How To Kill Viruses With Soap, Alcohol, Bleach, Lysol Sprays And Clorox Disinfectants

How To Kill Viruses To Prevent Infections In Humans


How To Kill Viruses With Alcohol, Bleach, Soap, Lysol Sprays, Copper, Vaccines, UV Light, Clorox Disinfectants And Hydrogen Peroxide

April 15, 2020 

Almost all cleaning products are in high demand in April 2020 because of allergies, the flu season and the coronavirus crisis. Buy the best EPA-approved disinfectants to kill the coronavirus here. Learn how to kill viruses in your home, water, laundry and body here. Get information on the best methods for killing viruses here. Find out how viruses are inhibited, inactivated and treated naturally, medicinally, chemically and scientifically. Read articles and take the "Influenza 101 Class" here.

Alcohol-Based Hand Sanitizer Compounders Protect Children By Using Denatured Ethanol Or Isopropyl Alcohol

The FDA provides guidance on the production of alcohol-based hand sanitizer to help boost supply and protect public health during the Coronavirus (COVID-19) crisis. The CDC and the FDA are helping to keep children safe by recommending that compounders use denatured alcohol and isopropyl alcohol to formulate and manufacture hand sanitizers and coronavirus disinfectants. Because denatured alcohol (ethanol/ethyl alcohol) tastes awful and it smells bad, this hand sanitizer ingredient discourages young children from eating coronavirus disinfectants. Denaturants in alcohol make it unfit for human consumption.

To protect young children from accidental poisoning caused by unintentionally ingesting coronavirus disinfectants and hand sanitizers, the CDC and FDA are recommending that compounders and consumers use denatured alcohol, isopropyl alcohol, hydrogen peroxide, glycerin (glycerol) and sterile water to prepare alcohol-based hand sanitizers for consumer use and for use as health care personnel hand rubs. Get updated core disinfection/cleaning guidance from the CDC here.

The USP Compounding Expert Committee (CMP EC) provides recommendations for compounding alcohol-based hand sanitizers for use during shortages associated with the COVID-19 pandemic. Download the USP recommendations here (PDF).

Coronavirus disinfectants ordered online at are used to clean the things that people touch the most such as phones, shopping carts, remote controls, tables, toilets, toothbrush holders, faucets, doorknobs, computer keyboards, light switches, desks, sinks and door handles.

Consumers and alcohol-based hand sanitizer manufacturers can order approved denatured alcohol (isopropyl alcohol and denatured ethyl alcohol), hydrogen peroxide, USP and FCC grade glycerin (glycerol)antiviral disinfectants, hospital grade disinfectants, raw materials for hand sanitizer ingredients and sterile water online at to make products to fight COVID-19.

Distilleries, compounders, sanitizer manufacturers, botanical makers and American households purchase disinfectants and other cleaning supplies online at to kill common viruses, mold, mildew, fungi, bacteria, pathogens and the novel coronavirus on contaminated surfaces.  Online orders of ingredients used to make coronavirus disinfectants, aerosol disinfectants and multipurpose cleaners surged in March of 2020.

To learn more about U.S. regulations concerning the use of denatured alcohol, please refer to the Electronic Code of Federal Regulations here. For guidance from the FDA for using denatured alcohol to make commercial hand sanitizers, please refer to this PDF titled, "Policy for Temporary Compounding of Certain Alcohol-Based Hand Sanitizer Products During the Public Health Emergency Immediately in Effect Guidance for Industry". 

Buy Ethanol To Make Your Own Hand Sanitizers, Surface Disinfectants And Household Cleaners To Use Against Coronavirus (SARS-CoV-2)

Properly made homemade hand sanitizer solutions can destroy the coronavirus. Ethanol Alcohol (ethyl alcohol) can be used at home to make your own hand sanitizer mixtures. Alcohol (ethanol) used for alcohol-based hand sanitizers is derived from distillation or fermentation processes typically used for consumable goods. Antiviral hand sanitizer ingredients are for sale online here. 60% ethanol or 70% isopropyl alcohol inactivates viruses. Help protect against coronavirus by cleaning and disinfecting frequently touched surfaces and objects in your home like tables, doorknobs, light switches, countertops, handles, desks, phones, keyboards, toilets, faucets, sinks, etc.

Canada's Interim Guide On The Production Of Ethanol For Use In Alcohol-Based Hand Sanitizers
May 8, 2020

On This Page 

This document provides information on the use of ethanol as an ingredient in alcohol-based hand sanitizers sold in Canada. Numerous Canadian entities and industries not currently regulated by Health Canada have expressed interest in providing additional and/or alternate sources of ethanol (also known as anhydrous alcohol, ethyl alcohol, or grain alcohol) for use in the production of hand sanitizers to support the national response to the supply shortage during the COVID-19 pandemic.

To help reduce the risk of infection or spreading infection to others, Health Canada recommends that individuals wash their hands often with soap and water, or use an alcohol-based hand sanitizer if soap and water are not available. Similarly, the World Health Organization (WHO) recommends that individuals regularly and thoroughly clean their hands with soap and water, or an alcohol-based hand rub, as part of proper hand hygiene.

On March 27, 2020, Health Canada released the Guide on Health Canada's Interim Expedited Licensing Approach for the Production and Distribution of Alcohol-Based Hand Sanitizers. The purpose of that Guide is to support companies that intend to manufacture, package, label and/or distribute alcohol-based hand sanitizers in response to the current shortage by providing a simplified and expedited pathway to obtaining the required authorizations.

This document provides further guidance on the quality requirements for ethanol to be used in the production of hand sanitizers. It also highlights key formulation aspects and points to additional flexibilities that can be leveraged during this emergency situation.

To protect the health and safety of Canadians, Health Canada remains committed to its mandate while balancing the need for exceptional measures during the COVID-19 pandemic. As such, the quality of ethanol used in manufacturing hand sanitizers must be fit for purpose and meet safety, efficacy and quality requirements.

This interim approach takes into account the current policies and best practices of foreign regulatory partners, including the United States (US) Food and Drug Administration (FDA), as well as the recommendations of the WHO and the US Pharmacopeia (USP).

Acceptable Quality Grades

Ethanol used for the production of hand sanitizers should conform to one of the identity and purity criteria published in any of the following quality standards, with any noted deviations provided in this interim guidance. For details on these quality standards, please refer to the weblinks provided below. Please note that some of these references may be accessed for free, while others require payment for full access:

The USP monograph specifies that ethanol must be 94.9% to 96.0% pure by volume, and provides the following concentration limits for impurities commonly found in ethanol:

  • Methanol: No more than 200 µL/L
  • Acetaldehyde and acetal: No more than 10 µL/L, expressed as acetaldehyde
  • Benzene: No more than 2 µL/L
  • Sum of all other impurities: No more than 300 µL/L

Recommended Formulation

All formulations must meet the safety and efficacy requirements established in Health Canada’s Antiseptic Skin Cleansers (Personal Domestic Use) monograph.

Health Canada recommends the manufacturing of ethanol‑based hand sanitizer as per the WHO formulation. Specifically, the WHO-recommended handrub formulations (2010) provides a recipe for the preparation of a hand sanitizer with a final concentration of 80% v/v ethanol. While Health Canada’s monograph stipulates a range of 60%-80 v/v ethanol, an 80% v/v concentration is recommended for increased efficacy.

Formulation For A 10-Litre Preparation 

Other Acceptable Formulations Include: 


Records must be maintained on how the hand sanitizer is prepared, including details on how the final ethanol dilution in the finished product was derived. The amount of ethanol needed in the formulation should be calculated using the following equation (as set out in the USP guidance):

How To Calculate The Amount Of Ethanol In A Hand Sanitizer Formulation

Non-Medicinal Ingredients (NMIs)

All NMIs added to a hand sanitizer product must be listed in Health Canada’s Natural Health Products Ingredient Database (NHPID), indicated with an acceptable purpose and comply with all listed restrictions (as per the NHPID). Additional information is outlined below on quality requirements for specific NMIs used in ethanol-based hand sanitizers, based on the WHO guidance:

NMI  Quality Requirements
Hydrogen Peroxide The low concentration of Hydrogen peroxide in the finished product (0.125%) is intended to help eliminate contaminating spores in the bulk solutions and recipients and is not an active substance for hand antisepsis.
Glycerol and other humectants or emollients

Glycerol (also known as glycerine or 1,2,3-Propanetriol) is added as a humectant at a final concentration of 1.45%, to increase the acceptability of the product and not to enhance viscosity.

Other humectants or emollients at a similar concentration may be used for skin care, provided that they are affordable, available locally, miscible (mixable) in water and alcohol, non-toxic, and not likely to cause an allergic reaction. Glycerol has been chosen because it is safe and relatively inexpensive. Lowering the percentage of glycerol may be considered to further reduce the stickiness of the handrub.

Use of proper
While sterile distilled water is preferred, boiled and cooled tap water may also be used as long as it is free of visible particles.
Addition of other additives It is strongly recommended that no ingredients other than those specified in this document be added to the formulations. All NMIs  (including denaturants) must be listed in the Product Licence application. If additions or substitutions of an NMI are made after the product licence is issued, documentation must be maintained on the safety of the additive and its compatibility with the other ingredients. These documents must be available upon request by Health Canada. Any substitutions should come from approved ingredients in the NHPID. If the NMI that you intend to use is not found in NHPID, you can complete a Natural Health Products Ingredients Database Issue Form and submit to this email to add the ingredient. The full list of ingredients must be provided on the product label.
Denaturants The use of denaturants is recommended to avoid the unintentional ingestion of hand sanitizers (particularly by children), but is not required under this interim approach. The NHPID includes a listing of acceptable denaturants that should be used if applicable in your formulation. Once this interim approach ceases to be in effect, to continue with the manufacture of hand sanitizer products, companies will be required to confirm with Health Canada that denaturants will be used from that point on.
Gelling agents No data are available to assess the suitability of adding gelling agents to WHO-recommended liquid formulations; any additives selected for this purpose must be listed in Health Canada’s NHPID and comply with listed restrictions. The addition of a gelling agent must be included in the list of ingredients on the product label.
Fragrances Adding fragrances, while not prohibited, is not recommended because of the risk of potential allergic reactions. As with other ingredients, a fragrance would be considered an NMI and must be included in the Product Licence application and be listed on the product label.


Formula Substitutions

Ingredients adhering to USP (or other acceptable standards, as listed above) should be used as the source of ingredients. However, given that there may currently be shortages of ingredients used to manufacture formulations of alcohol-based hand sanitizers, the following substitutions are acceptable:

  • When components meeting compendial quality standards are not obtainable, components of similar quality – such as those that are chemically pure, analytical reagent grade, or American Chemical Society-certified – may be used.
  • No ingredients should be added to enhance viscosity as they may decrease the effectiveness of the final preparation.

Disinfectant product ingredients, whether registered with the US Environmental Protection Agency or Health Canada, are not suitable as components for manufacturing hand sanitizers as they may not be safe for use on skin (i.e., may cause burns).

Use Of Non-USP Grade Alcohol

As per the Natural Health Products Regulations (NHPR), a Product Licence will not be issued if a product is likely to result in injury to the health of the consumer. Non-USP grade ethanol should be of a level of quality that is fit for human use in the finished hand sanitizer formulation.

For any products containing ethanol with specifications that deviate from the recommended standards, such as higher than permitted level of impurities in the above referenced standards, a risk assessment must be conducted and submitted to Health Canada for review. Each risk assessment will be evaluated on a case-by-case basis to determine if the ethanol is safe for use in hand sanitizer production. In the risk assessment, particular attention should be given to identify and quantify impurities, which are expected to be present (or likely to be present) as a result of manufacturing processes, starting materials, etc. An example of some impurities that would be expected in a non-USP or food grade ethanol product include acetaldehyde, benzene and methanol, though there may be others as well. Documentation including certificates of analysis (CoA) must be kept on record and made available at the request of Health Canada.

Excise Tax Implications

The Canada Revenue Agency (CRA) administers the Excise Act, 2001 which governs the federal taxation of several commodities, including spirits, and regulates activities involving the manufacture, possession and distribution of these products. For example, persons who produce and package spirits, persons who use non-duty-paid spirits in the manufacture of non-beverage spirit-based products such as cosmetics or hand sanitizers, and persons who operate warehouses to store non-duty-paid alcohol must possess an excise duty licence issued under the Excise Act, 2001.

Depending on the circumstances, a person may require a spirits licence, a user’s licence and/or a specially denatured alcohol registration in order to legally produce hand sanitizer using non-duty-paid alcohol in Canada. There are a number of ways hand sanitizer can be produced by licensees or registrants without incurring an excise duty liability, for example:

  • A user licensee can produce hand sanitizer in accordance with an approved formulation without the payment of excise duty on the final product.
  • There are also provisions that would allow a specially denatured alcohol registrant to possess and use certain grades of specially denatured alcohol to produce hand sanitizer without the payment of duty.
  • A spirits licensee is authorized under the Excise Act, 2001 to denature spirits according to specified criteria, which are not subject to excise duty.
  • Although it could be cost prohibitive, there is also the option to use duty-paid alcohol to produce hand sanitizer. 

The requirements under the Act will vary depending on the circumstances of each case and the proposed activities to be undertaken.

Obtaining A Licence, Registration And/Or Approved Formulation Under The Excise Act, 2001

A number of spirits licensees, licenced users and brewer licensees (excise licensees) have expressed an interest in using non-duty-paid alcohol to make hand sanitizer. These are existing excise licensees who are seeking to temporarily expand their operations in response to the shortage in supply as a result of the COVID-19 pandemic. In some cases, excise licensees are requesting specially denatured alcohol registrations to allow them to possess and use specially denatured alcohol for this purpose. In other cases, spirits or brewer licensees are requesting users’ licences and approved formulations. The CRA is also receiving enquiries from non-licensees who would like to apply for a specially denatured alcohol registration or user’s licence and approved formulation for the purpose of producing hand sanitizer. In response to the current circumstances, the CRA has implemented a streamlined process to expedite the review and approval of these applications.

Applications for users’ licences and specially denatured alcohol registrations should be submitted to your regional excise duty office using Form L63 Licence and Registration Application Excise Act, 2001. Applications for formulation approval should be submitted using Form Y15D - Request for Formula Approval. Note that a sample is not currently required for excise licensees applying for an approved formulation for the production of hand sanitizer. For questions or further information, please visit this website Excise Duties, Excise Taxes, Fuel Charge and Air Travellers Security Charge, which also includes the contact information for your regional excise duty office. These regional offices are your best source for information on excise taxes.

End Of Interim Approach

This interim approach is in effect immediately, and will be in effect until March 31, 2021 or until a notice is issued by Health Canada to licence holders (whichever is earliest). When the approach expires, production must cease, although existing product stock can be exhausted.

Contact Health Canada

If you have questions in relation to this Guide or the licensing of alcohol-based hand sanitizers, please contact Health Canada's Natural and Non-prescription Health Products Directorate at

Information On Hand Sanitizer Ingredients From Wikipedia

Hand sanitizer is a liquid, gel, or foam generally used to decrease infectious agents on the hands. In most settings, hand washing with soap and water is generally preferred. Hand sanitizer is less effective at killing certain kinds of germs, such as norovirus and Clostridium difficile and unlike soap and water, it cannot remove harmful chemicals. People may incorrectly wiped off hand sanitizer before it has dried, and some are less effective because their alcohol concentrations are too low.

In most healthcare settings alcohol-based hand sanitizers are preferable to hand washing with soap and water. Reasons include it being better tolerated and more effective. Hand washing with soap and water; however, should be carried out if contamination can be seen, or following the use of the toilet. The general use of non-alcohol-based hand sanitizers has no recommendations.

Alcohol-based versions typically contain some combination of isopropyl alcohol, ethanol (ethyl alcohol), or n-propanol, with versions containing 60% to 95% alcohol the most effective. Care should be taken as they are flammable. Alcohol-based hand sanitizer works against a wide variety of microorganisms but not spores. Compounds such as glycerol may be added to prevent drying of the skin. Some versions contain fragrances; however, these are discouraged due to the risk of allergic reactions. Non-alcohol based versions typically contain benzalkonium chloride or triclosan; but are less effective than alcohol-based ones. 

Alcohol has been used as an antiseptic at least as early as 1363 with evidence to support its use becoming available in the late 1800s. Alcohol-based hand sanitizer has been commonly used in Europe since at least the 1980s. The alcohol-based version is on the World Health Organization's List of Essential Medicines, the safest and most effective medicines needed in a health system. The wholesale cost in the developing world is about US$1.40–3.70 per liter bottle.


General Public 

The Clean Hands campaign by the US Centers for Disease Control and Prevention (CDC) instructs the public in hand washing. Alcohol-based hand sanitizer is recommended only if soap and water are not available.

When using an alcohol-based hand sanitizer:

  • Apply product to the palm of one hand.
  • Rub hands together.
  • Rub the product over all surfaces of hands and fingers until hands are dry.
  • Do not go near flame or gas burner or any burning object during applying hand sanitizer.
  • The current evidence for the effectiveness of school hand hygiene interventions is of poor quality.

Alcohol-based hand sanitizers may not be effective if the hands are greasy or visibly soiled. In hospitals, the hands of healthcare workers are often contaminated with pathogens, but rarely soiled or greasy. In community settings, on the other hand, grease and soiling is common from activities such as handling food, playing sports, gardening, and being active outdoors. Similarly, contaminants like heavy metals and pesticides (generally found outdoors) cannot be removed by hand sanitizers. Hand sanitizers may also be swallowed by children, especially if brightly-coloured.

Some commercially-available hand sanitizers (and online recipes for homemade rubs) have alcohol concentrations that are too low. This makes them less effective at killing germs. Poorer people in developed countries and people in developing countries may find it harder to get a hand sanitizer with an effective alcohol concentration. Fraudulent labelling of alcohol concentrations has been a problem in Guyana.

Health Care 

Hand sanitizers were first introduced in 1966 in medical settings such as hospitals and healthcare facilities. The product was popularized in the early 1990s.

Alcohol-based hand sanitizer is more convenient compared to hand washing with soap and water in most situations in the healthcare setting. Among healthcare workers, it is generally more effective for hand antisepsis, and better tolerated than soap and water. Hand washing should still be carried out if contamination can be seen or following the use of the toilet.

Hand sanitizer that contains at least 60% alcohol or contains a "persistent antiseptic" should be used. Alcohol rubs kill many different kinds of bacteria, including antibiotic resistant bacteria and TB bacteria. They also kill many kinds of viruses, including the flu virus, the common cold virus, coronaviruses, and HIV.

90% alcohol rubs are more effective against viruses than most other forms of hand washing. Isopropyl alcohol will kill 99.99 % or more of all non-spore forming bacteria in less than 30 seconds, both in the laboratory and on human skin.

The alcohol in hand sanitizers may not have the 10–15 seconds exposure time required to denature proteins and lyse cells in too low quantities (0.3 ml) or concentrations (below 60%). In environments with high lipids or protein waste (such as food processing), the use of alcohol hand rubs alone may not be sufficient to ensure proper hand hygiene.

For health care settings like hospitals and clinics, optimum alcohol concentration to kill bacteria is 70% to 95%. Products with alcohol concentrations as low as 40% are available in American stores, according to researchers at East Tennessee State University.

Alcohol rub sanitizers kill most bacteria, and fungi, and stop some viruses. Alcohol rub sanitizers containing at least 70% alcohol (mainly ethyl alcohol) kill 99.9% of the bacteria on hands 30 seconds after application and 99.99% to 99.999% in one minute.

For health care, optimal disinfection requires attention to all exposed surfaces such as around the fingernails, between the fingers, on the back of the thumb, and around the wrist. Hand alcohol should be thoroughly rubbed into the hands and on the lower forearm for a duration of at least 30 seconds and then allowed to air dry.

Use of alcohol-based hand gels dries skin less, leaving more moisture in the epidermis, than hand washing with antiseptic/antimicrobial soap and water.


There are certain situations during which hand washing with soap and water are preferred over hand sanitizer, these include: eliminating bacterial spores of Clostridioides difficile, parasites such as Cryptosporidium, and certain viruses like norovirus depending on the concentration of alcohol in the sanitizer (95% alcohol was seen to be most effective in eliminating most viruses). In addition, if hands are contaminated with fluids or other visible contaminates, hand washing is preferred as well as after using the toilet and if discomfort develops from the residue of alcohol sanitizer use. Furthermore, CDC states hand sanitizers are not effective in removing chemicals such as pesticides.


Alcohol gel can catch fire, producing a translucent blue flame. This is due to the flammable alcohol in the gel. Some hand sanitizer gels may not produce this effect due to a high concentration of water or moisturizing agents. There have been some rare instances where alcohol has been implicated in starting fires in the operating room, including a case where alcohol used as an antiseptic pooled under the surgical drapes in an operating room and caused a fire when a cautery instrument was used. Alcohol gel was not implicated.

To minimize the risk of fire, alcohol rub users are instructed to rub their hands until dry, which indicates that the flammable alcohol has evaporated. Igniting alcohol hand rub while using it is rare, but the need for this is underlined by one case of a health care worker using hand rub, removing a polyester isolation gown, and then touching a metal door while her hands were still wet; static electricity produced an audible spark and ignited the hand gel. Fire departments suggest refills for the alcohol-based hand sanitizers can be stored with cleaning supplies away from heat sources or open flames.

Research shows that alcohol hand sanitizers do not pose any risk by eliminating beneficial microorganisms that are naturally present on the skin. The body quickly replenishes the beneficial microbes on the hands, often moving them in from just up the arms where there are fewer harmful microorganisms.

However, alcohol may strip the skin of the outer layer of oil, which may have negative effects on barrier function of the skin. A study also shows that disinfecting hands with an antimicrobial detergent results in a greater barrier disruption of skin compared to alcohol solutions, suggesting an increased loss of skin lipids.

In the United States, the U.S. Food and Drug Administration (FDA) controls antimicrobial handsoaps and sanitizers as over-the-counter drugs (OTC) because they are intended for topical anti-microbial use to prevent disease in humans.

The FDA requires strict labeling which informs consumers on proper use of this OTC drug and dangers to avoid, including warning adults not to ingest, not to use in the eyes, to keep out of the reach of children, and to allow use by children only under adult supervision. According to the American Association of Poison Control Centers, there were nearly 12,000 cases of hand sanitizer ingestion in 2006. If ingested, alcohol-based hand sanitizers can cause alcohol poisoning in small children. However, the U.S. Centers for Disease Control recommends using hand sanitizer with children to promote good hygiene, under supervision, and furthermore recommends parents pack hand sanitizer for their children when traveling, to avoid their contracting disease from dirty hands.

There have been reported incidents of people drinking the gel in prisons and hospitals, where alcohol consumption is not allowed, to become intoxicated leading to its withdrawal from some establishments.


On April 30, 2015, the FDA announced that they were requesting more scientific data based on the safety of hand sanitizer. Emerging science suggests that for at least some health care antiseptic active ingredients, systemic exposure (full body exposure as shown by detection of antiseptic ingredients in the blood or urine) is higher than previously thought, and existing data raise potential concerns about the effects of repeated daily human exposure to some antiseptic active ingredients. This would include hand antiseptic products containing alcohol and triclosan.

Surgical Hand Disinfection

Hands must be disinfected before any surgical procedure by hand washing with mild soap and then hand-rubbing with a sanitizer. Surgical disinfection requires a larger dose of the hand-rub and a longer rubbing time than is ordinarily used. It is usually done in two applications according to specific hand-rubbing techniques, EN1499 (hygienic handwash), and EN 1500 (hygienic hand disinfection) to ensure that antiseptic is applied everywhere on the surface of the hand.


Some hand sanitizer products use agents other than alcohol to kill microorganisms, such as povidone-iodine, benzalkonium chloride or triclosan. The World Health Organization (WHO) and the CDC recommends "persistent" antiseptics for hand sanitizers. Persistent activity is defined as the prolonged or extended antimicrobial activity that prevents or inhibits the proliferation or survival of microorganisms after application of the product. This activity may be demonstrated by sampling a site several minutes or hours after application and demonstrating bacterial antimicrobial effectiveness when compared with a baseline level. This property also has been referred to as "residual activity." Both substantive and nonsubstantive active ingredients can show a persistent effect if they substantially lower the number of bacteria during the wash period.

Laboratory studies have shown lingering benzalkonium chloride may be associated with antibiotic resistance in MRSA. Tolerance to alcohol sanitizers may develop in fecal bacteria. Where alcohol sanitizers utilize 62%, or higher, alcohol by weight, only 0.1 to 0.13% of benzalkonium chloride by weight provides equivalent antimicrobial effectiveness.

Triclosan has been shown to accumulate in biosolids in the environment, one of the top seven organic contaminants in waste water according to the National Toxicology Program Triclosan leads to various problems with natural biological systems, and triclosan, when combined with chlorine e.g. from tap water, produces dioxins, a probable carcinogen in humans. However, 90–98% of triclosan in waste water biodegrades by both photolytic or natural biological processes or is removed due to sorption in waste water treatment plants. Numerous studies show that only very small traces are detectable in the effluent water that reaches rivers.

A series of studies show that photodegradation of triclosan produced 2,4-dichlorophenol and 2,8-dichlorodibenzo-p-dioxin (2,8-DCDD). The 2,4-dichlorophenol itself is known to be biodegradable as well as photodegradable. For DCDD, one of the non-toxic compounds of the dioxin family, a conversion rate of 1% has been reported and estimated half-lives suggest that it is photolabile as well. The formation-decay kinetics of DCDD are also reported by Sanchez-Prado et al. (2006) who claim "transformation of triclosan to toxic dioxins has never been shown and is highly unlikely."

Alcohol-free hand sanitizers may be effective immediately while on the skin, but the solutions themselves can become contaminated because alcohol is an in-solution preservative and without it, the alcohol-free solution itself is susceptible to contamination. However, even alcohol-containing hand sanitizers can become contaminated if the alcohol content is not properly controlled or the sanitizer is grossly contaminated with microorganisms during manufacture. In June 2009, alcohol-free Clarcon Antimicrobial Hand Sanitizer was pulled from the US market by the FDA, which found the product contained gross contamination of extremely high levels of various bacteria, including those which can "cause opportunistic infections of the skin and underlying tissues and could result in medical or surgical attention as well as permanent damage". Gross contamination of any hand sanitizer by bacteria during manufacture will result in the failure of the effectiveness of that sanitizer and possible infection of the treatment site with the contaminating organisms.


Alcohol-based hand rubs are extensively used in the hospital environment as an alternative to antiseptic soaps. Hand-rubs in the hospital environment have two applications: hygienic hand rubbing and surgical hand disinfection. Alcohol based hand rubs provide a better skin tolerance as compared to antiseptic soap. Hand rubs also prove to have more effective microbiological properties as compared to antiseptic soaps.

The same ingredients used in over-the-counter hand-rubs are also used in hospital hand-rubs: alcohols such ethanol and isopropanol, sometimes combined with quaternary ammonium cations (quats) such as benzalkonium chloride. Quats are added at levels up to 200 parts per million to increase antimicrobial effectiveness. Although allergy to alcohol-only rubs is rare, fragrances, preservatives and quats can cause contact allergies. These other ingredients do not evaporate like alcohol and accumulate leaving a "sticky" residue until they are removed with soap and water.

The most common brands of alcohol hand rubs include Aniosgel, Avant, Sterillium, Desderman and Allsept S. All hospital hand rubs must conform to certain regulations like EN 12054 for hygienic treatment and surgical disinfection by hand-rubbing. Products with a claim of "99.99% reduction" or 4-log reduction are ineffective in hospital environment, since the reduction must be more than "99.99%".

The hand sanitizer dosing systems for hospitals are designed to deliver a measured amount of the product for staff. They are dosing pumps screwed onto a bottle or are specially designed dispensers with refill bottles. Dispensers for surgical hand disinfection are usually equipped with elbow controlled mechanism or infrared sensors to avoid any contact with the pump.


In 2010 the World Health Organization produced a guide for manufacturing hand sanitizer, which received renewed interest because of shortages of hand sanitizer in the wake of the COVID-19 pandemic. Dozens of liquor and perfume manufactures switched their manufacturing facilities from their normal product to hand sanitizer. In order to keep up with the demand, local distilleries started using their alcohol to make hand sanitizer. Distilleries producing hand sanitizer originally existed in a legal grey area in the United States, until the Alcohol and Tobacco Tax and Trade Bureau declared that distilleries could produce their sanitizer without authorization.

There are cautions against making your own hand sanitizer. Some widely-circulated home recipes are ineffective or even poisonous.


World Health OrganizationThe has published a guide to producing large quantities of hand sanitizer from chemicals available in developing countries, where commercial hand sanitizer may not be available:

FORMULATION 1  10-L prep. Active ingredient (v/v) FORMULATION 2 10-L prep. Active ingredient (v/v)
Distilled water added to 10000 mL 18.425% Distilled water added to 10000 mL 23.425%
Ethanol 96% 8333 mL 80% Isopropyl alcohol 99.8% 7515 mL 75%
Glycerol 98% 145 mL 1.45% Glycerol 98% 145 mL 1.45%
Hydrogen peroxide 3% 417 mL 0.125% Hydrogen peroxide 3% 417 mL 0.125%


The WHO formulation are less viscous than commercial sanitizer gel, so like alcohol, they are a greater fire hazard.

Consumer alcohol-based hand sanitizers, and health care "hand alcohol" or "alcohol hand antiseptic agents" exist in liquid, foam, and easy-flowing gel formulations. Products with 60% to 95% alcohol by volume are effective antiseptics. Lower or higher concentrations are less effective; most products contain between 60% and 80% alcohol.

In addition to alcohol (ethanol, isopropanol or n-Propanol), hand sanitizers also contain the following:

Hydrogen peroxide may be added to inactivate spores within bottle of hand sanitizer but does not play a role when the hand sanitizer is used.

Coronavirus Outbreak - Use Ethanol (Ethyl Alcohol) To Make Household Surface Disinfectants And Commercial Cleaners To Control Coronavirus COVID-19 (SARS-CoV-2)

To increase the supply of hand sanitizers, the FDA issued guidance for manufacturers that would like to produce alcohol (ethanol or ethyl alcohol) for use in alcohol-based hand sanitizers for consumers and health care personnel. has addressed shortages of alcohol-based hand sanitizers associated with the COVID-19 pandemic by stocking the ingredients used to compound alcohol-based hand sanitizers. Buy safe chemical ingredients to make DIY homemade hand sanitizers and commercial cleaning solutions, here. Buy coronavirus disinfectants and sprays for household use, here. Prices for antiviral disinfectants, sanitizers and wipes start at $5.

Drinking methanol, ethanol or bleach DOES NOT prevent or cure COVID-19 and can be extremely dangerous. Methanol, ethanol, and bleach are poisons.

The World Health Organization (WHO) has reported an outbreak of disease caused by a novel coronavirus (referred to as 2019 Novel Coronavirus (2019-nCoV)).  This is an evolving situation, and it is recommended that all concerned consult the WHO, the United States Centers for Disease Control and Prevention (U.S. CDC) and the United States Environmental Protection Agency (U.S. EPA) websites frequently for the most updated information regarding the outbreak. 

Buy The Best Virus Disinfectants, Antimicrobial Sprays, Antibacterial Wipes And Household Cleaning Supplies Online

Buy 70% Ethyl Alcohol And 70% Isopropyl Alcohol For Sterilization And To Kill Viruses And Bacteria

Ethyl Alcohol (70%) is the most effective concentration for bactericidal and virucidal uses70% ethyl alcohol sold by is a potent cleaning agent used to kill viruses, destroy microbes, denature proteins and dissolves lipid (fat) membranes surrounding viruses. Alcohol denatures proteins by disrupting the side chain intramolecular hydrogen bonding. Read the CDC disinfection and sterilization guidelines for chemical disinfectants here. U.S. consumers can also buy 100% ethanol without a license at

Buy Coronavirus (COVID-19) Disinfectant Cleaners That Meet EPA Standards To Protect Yourself, Your Family, Your Employees And Customers

This website provides key EPA resources on the coronavirus disease (COVID-19). 70% antibacterial and antifungal denatured alcohol and ethanol sold online at are great virucidal disinfectants and hand sanitizers against non-enveloped viruses as well as single-stranded, positive-sense RNA viruses such as coronaviruses (CoVs). Coronavirus is enveloped which means that it has a coating on the outside

Ethanol and isopropyl alcohol are used throughout the world for disinfecting environmental surfaces in health care communities and for hand disinfection and hand rubbing. It has been noted that ethanol has a stronger and broader virucidal activity than propanols such as isopropanol.

Coronaviruses are host-specific and can infect humans as well as animals, cats and dogs causing a variety of clinical syndromes. Dogs can contract coronaviruses, most commonly the canine respiratory coronavirus. This specific novel coronavirus (COVID-19) is not a health threat to dogs, but dogs can test positive for the virus.

Coronaviruses are single-stranded, positive-sense RNA viruses with a genome of approximately 30 kb, the largest genome among RNA viruses. These viruses were named coronaviruses because by electron microscopy they have club-shaped surface projections that give them a crownlike appearance. Coronaviruses derive their name from the fact that under electron microscopic examination, each virion is surrounded by a “corona,” or halo.

Non-enveloped viruses do not have a lipid-bilayer membrane. Non-enveloped viruses reproduce by breaching the membrane of a target host cell to get access to cytoplasm of the cell. A virus encased within a lipid bilayer is called an enveloped virus and a virus that does not have a bilayer is classified as a non-enveloped virus.

Buy Coronavirus Disinfectants Online At For Infection Control In U.S. Households And Community Facilities

Due to the coronavirus outbreak, U.S. businesses and consumers order EPA recommended disinfectants and sanitizers in bulk at for cleaning and disinfecting for the coronavirus (SARS-CoV-2) and to kill germs on surfaces in households and community facilities.

The 70% ethyl alcohol sold by is a better virucide than the 70% isopropyl alcohol and is quickly antimicrobial against viruses, bacteria and fungi on hard surfaces. 

Isopropanol (isopropyl alcohol ) and ethyl alcohol in aqueous solutions between 60% and 90% alcohol with 10% to 40% purified water, kill bacteria and viruses by denaturing their proteins and dissolving their lipid membranes. When a bacterial cell is exposed to a solution of ethyl alcohol or isopropyl alcohol, the amphiphile alcohol molecules bond with the molecules of the bacteria's cell membrane, making it more soluble in water. This reaction causes the cell membrane to lose its structural integrity and then fall apart.

Buy Ethyl Alcohol And Isopropyl Alcohol At To Kill Coronaviruses And Be Sure To Also Use Soap And Water

Ethyl alcohol, isopropyl alcohol and soap all kill the coronavirus. Soap contains fat-like substances known as amphiphiles, which are structurally very similar to lipids in virus membranes. Soap loosens the bond between viruses and skin which helps decrease the spread of viruses. Soap also loosens the Velcro-like interactions that hold the proteins, lipids and RNA in the virus together. Alcohol-based disinfectant products sold at that contain a high-percentage alcohol solution (normally 70% ethanol and 70% isopropyl alcohol) kill viruses in the same way. Additionally, the mechanical action of hand washing with soap loosens viruses and bacteria from the skin.

The CDC recommends using an alcohol-based hand rub (ABHR) with greater than 60% ethanol or 70% isopropyl alcohol in healthcare environments. Unless hands are visibly soiled, an ABHR is recommended over soap and water in clinical situations because of evidence of better compliance compared to soap and water. Hand rubs are normally less irritating to hands and are effective in the absence of a sink.  Hands should be washed with soap and water for at least 20 seconds when visibly soiled, before eating, and after using the restroom. Learn more about hand hygiene in healthcare facilities here.

Buy Alcohol-Based Disinfectants At To Compound Hand Sanitizers And To Keep Viruses From Replicating

Alcohol-based hand sanitizer compounders protect children by using denatured ethanol or isopropyl alcohol. The FDA provides guidance on the production of alcohol-based hand sanitizer to help boost supply and protect public health during the Coronavirus (COVID-19) crisis. Viruses intricately interact with and modulate cellular membranes at several stages of their replication, but much less is known about the role of viral lipids compared to proteins and nucleic acids.

All animal viruses have to cross membranes for cell entry and exit, which occurs by membrane fusion (in enveloped viruses), by transient local disruption of membrane integrity, or by cell lysis. The CDC and the FDA are helping to keep children safe by recommending that compounders use denatured alcohol and isopropyl alcohol to formulate and manufacture hand sanitizers and coronavirus disinfectants. 

Viruses are obligatory intracellular parasites that are simple in structure and composition, but engage in multiple and complex interactions with their host. Virus replication occurs exclusively inside the respective host cell. Accordingly, viruses have to cross the host cell boundary at least twice during their replication cycle, for entry and exit. Because these viral membranes are derived from the host, they may contain a complement of membrane-bound host cell proteins.

Because denatured alcohol (ethanol/ethyl alcohol) tastes awful and it smells bad, this hand sanitizer ingredient discourages young children from eating coronavirus disinfectants. Denaturants in alcohol make it unfit for human consumption.

Buy 70% Denatured Alcohol And 70% Isopropyl Alcohol To Combat Coronavirus

Both 70% denatured ethanol (140 proof) and 70% isopropyl alcohol are excellent disinfectants for surface-cleaning uses. 70% isopropyl alcohol is frequently used as an antiseptic in hospitals. Because of an increased demand for alcohol-based hand sanitizers during the COVID-19 pandemic, many U.S. healthcare facilities are augmenting their cleaning supplies by ordering ethyl alcohol (70%) and 70% isopropyl alcohol at In April of 2020, tons of 70% alcohol were ordered online at for large-scale disinfection efforts against coronavirus and for household cleaningsanitation and sterilization purposes in the U.S.

Buy antimicrobial disinfectants such as ethanol 70%, sodium hypochlorite and isopropanol to control Methicillin-resistant Staphylococcus aureus (MRSA) infections in homes and healthcare settings. Buy ingredients for safe recipes for DIY homemade hand sanitizers hereBuy coronavirus disinfectants here. Buy hospital grade disinfectants online here.   



    There is scientific research that indicates that the following items can mitigate and inactivate viruses: soap, Clorox Disinfecting Bleach, EPA-registered disinfectants, Lysol Clean & Fresh Multi-Surface Cleaner, hydrogen peroxide, Clorox Toilet Bowl Cleaner with Bleach, Microban, antiviral hand sanitizer ingredients, 70% alcohol, sodium hypochlorite, Clorox Pet Solutions Stain & Odor Remover, household cleaners, herbs, antiviral drugs, food, hydroxychloroquine, chloroquine, UV light, copper, essential oils, detergents, chlorine and vaccines. Study the basics of the flu virus and influenza surveillance reports here.



    Many Americans wonder how to kill viruses on their hands, in the air, in their laundry, in their cars and in water. Alcohol-based hand sanitizers can quickly reduce the number of microbes on hands in some situations, but sanitizers do not eliminate all types of germs. Soap kills viruses on hands. The CDC states that you can kill viruses in your laundry by washing clothes in a machine with detergent. You can use isopropyl alcohol to kill viruses in your car without damaging interior surfaces. Air purifiers can remove flu viruses from the air.

    Frightened citizens hope that their immune system can defeat SARS-CoV-2. They want to use safe high purity chemicals, hand sanitizers and EPA-registered disinfectants to avoid contracting SARS-CoV-2. Tiny infectious agents can wreak havoc globally. Millions of people around the globe want to use high grade (A+) household cleaning products to slay viruses in their home, in their cars and on their toothbrush.

    Since ancient times, Homo sapiens have used food, herbs and plants to prevent and eliminate viruses in their body. Turmeric has been used in Chinese and Ayurvedic medicine to terminate viruses for 4,000 years. Now, millennials try to find out how to annihilate viruses on their iPhone and on their clothes. Concerned parents want to know how to decimate viruses on dishes, carpets and computers. Viruses 101 delves into the world of microscopic killers.

    Our bodies and our immune responses are constantly fighting off viruses. Antibodies remove viruses in our body before they get a chance to cause infection. Clorox wipes, Lysol spray and other EPA-approved products can kill viruses in your home and car. Households should be cleaned and disinfected to limit the survival of viruses.

    Medicines, antiviral drugs, antiretroviral drugs and antiretroviral therapy (ATV) are used to kill and treat HIV, genital herpes, flu, shingles, Ebola, colds, HPV and Hepatitis B. Viruses are not directly killed by antiviral medications. These drugs trap the virus in human cells and stop it from replicating.

    Scientists study how to inactivate viruses in humans with radiation, electricity, UV light, frequency and ultrasonic energy. Folks go online to study the science of soap to find out how it rubs out the coronavirus. Nobody wants to get sick. Doctors want to save lives. There is a global quest to comprehend, mitigate, and prevent COVID-19

    Isopropyl Alcohol For Coronavirus 

    If your local store is out of hand sanitizer, buy isopropyl alcohol (better known as rubbing alcohol) at to make do-it-yourself sanitizers. Tests have confirmed that two hand sanitizer formulations recommended by the World Health Organization (WHO) inactivate the virus that causes coronavirus disease 19 (COVID-19). Hand sanitizer can be made out of either ethyl alcohol, like the ethanol in alcoholic beverages, or isopropyl alcohol. Rubbing alcohol that's at least 70% alcohol will also kill coronavirus on surfaces; 60% for your hands. 

    ExxonMobil makes isopropyl alcohol to help with the coronavirus effort. The firm recently reconfigured a facility to manufacture medical-grade hand sanitizer, which will be donated to health care providers and first responders. 

    How To Make Your Own Hand Sanitizer | Dr. Ian Smith


    Does Hydrogen Peroxide Kill Coronavirus?

    Yes, in all probability, SARS-CoV-2 can be efficiently inactivated with surface disinfection procedures that use hydrogen peroxide ordered at That being said, no hydrogen product exists in the U.S. market that has been tested to kill SARS-CoV-2 and approved by U.S. regulatory agencies such as the EPA or FDA.

    Vaporized hydrogen peroxide is an effective decontamination method for masks and N95 respirators that have been contaminated by SARS-CoV-2. The U.S. Food and Drug Administration issued an emergency use authorization (EUA) to decontaminate compatible N95 or N95-equivalent respirators with vaporized hydrogen peroxide sterilizers.

    3% hydrogen peroxide purchased online at is used as a spray sanitizer to kill rhinovirus on surfaces. Because scientists claim that coronaviruses are easier to kill than rhinovirus, hydrogen peroxide should kill SARS-CoV-2. Hydrogen peroxide should not be used to treat COVID-19, which is the disease caused by the novel coronavirus.

    Because the first confirmation of a case of 2019-nCoV (original name) was just confirmed on January 21, 2020, scientific studies and research to unequivocally validate that hydrogen peroxide will completely inactivate the SARS-CoV-2 virus are still ongoing. However, many products on the EPA List N Disinfectants For Use Against SARS-CoV-2 contain hydrogen peroxide. Duke University and Health System, will begin using hydrogen peroxide vapor to decontaminate and reuse N95 respirators.

    Hydrogen peroxide is active against a wide range of microorganisms, including bacteria, yeasts, fungi, viruses, and spores. The CDC provides information on the effectiveness of hydrogen peroxide solutions against viruses. The hydrogen peroxide solutions listed on the CDC website include 0.5% accelerated hydrogen peroxide, 3% concentration, 6% hydrogen peroxide, 10% hydrogen peroxide solution, 7% stabilized hydrogen peroxide and 13.4% hydrogen peroxide.

    Buy Coronavirus Disinfectants For Professional Cleaning Staffs

    Cleaning professionals use coronavirus disinfection products ordered online at to clean and safely disinfect for the novel coronavirus (SARS-CoV-2). The ISSA (Worldwide Cleaning Industry Association) offers education, training, and business resources to help cleaning workers manage the COVID-19 outbreak. Learn how to get trained to clean and disinfect for coronavirus here.

    Clorox Disinfecting Wipes, Bleach Free Cleaning Wipes Fresh, Fresh Scent

    Clorox Disinfecting Wipes, Bleach Free Cleaning Wipes Fresh, Fresh Scent

    Advanced Fresh Scent formula. Removes tough soap scum. Eliminate 99.9% of household germs. DISINFECTING WIPES: Clean and disinfect with a powerful antibacterial wipe killing 99.9% of bacteria and viruses and remove common allergens around your home. ALL PURPOSE WIPE: The canister allows you to keep the cleaning wipes easily accessible where and when you need to clean up a mess. MULTI-SURFACE CLEANER: Germs and messes occur on more than kitchen counters and bathroom surfaces - conveniently tackle any tough surface including finished wood, sealed granite and stainless steel. DISPOSABLE WIPES: This 35 count canister of disposable, antibacterial wipes features a Fresh Scent (do not flush wipes). NO BLEACH: Disinfect and deodorize with the fresh smell of Clorox disinfecting wipes for a bleach-free, all-in-one cleaning alternative. Safely wipe down toys, remotes, or clean up car spills with these sanitizing wipes. Packaging May Vary. Clorox Disinfecting Wipes is an all-purpose wipe that cleans and disinfects with antibacterial power killing 99.9% of viruses and bacteria in a Fresh Scent. These disposable wipes remove common allergens, germs and messes on kitchen counters, bathroom surfaces and more. Each wipe can kill cold and flu viruses and bacteria including Human Coronavirus, Influenza A2 Virus, Staph, E. coli, MRSA, Salmonella, Strep and Kleb that can live on surfaces for up to 48 hours. Conveniently and safely tackle any tough surface including finished wood, sealed granite and stainless steel. Use on hard, nonporous, non-food-contact surfaces found in the home, office, classroom, pet area, dorm and locker room. Disinfect and deodorize with the fresh smell of Clorox clean in this bleach-free formula that you can keep anywhere dirt or germs may build up. Clean with the trusted power of Clorox Disinfecting Wipes.

    Clorox Disinfecting Bathroom Cleaner, Spray Bottle, 30 Ounces


    Clorox Disinfecting Bathroom Cleaner, Spray Bottle, 30 Ounces

    Clorox Disinfecting Bathroom Spray cleaner has been proven to cut through dirt, grime and soap scum faster than the leading bathroom cleaner. It also kills germs commonly found in the bathroom such as Salmonella choleraesuis (Salmonella), Staphylococcus aureus (Staph), Rhinovirus Type 37 and Influenza A virus (Hong Kong). This cleaner leaves behind no dull residue and is perfect for freshening and cleaning tubs, tile, toilets, sinks and counters. The Smart Tube technology insures you spray every stain fighting drop. Behind every sparkling clean bathroom, there is Clorox Disinfecting Bathroom Spray. BATHROOM CLEANER: Make your bathroom sparkle with Clorox Disinfecting Bathroom Cleaner in a spray bottle that cleans, disinfects and kills 99.9% of viruses and bacteria.



    EPA-registered disinfectantsrubbing alcoholhousehold cleaning productschemicalssodium hypochloritetea tree oilsolvents (like hexane and methanol) and bleach kill viruses. California’s comprehensive and safe drinking water standards require a multi-step treatment process that includes filtration and disinfection. This process removes and kills viruses, including coronaviruses such as COVID-19, as well as bacteria and other pathogens.



    Plant extracts, organic acids, antiviral compounds (AVCs), disinfectants, UV light, food, solvent/detergent (S/D) treatments, pasteurization, antiviral drugs, spices, alcohol, copper, herbal medicinesCRISPR and vaccines inactivate viruses and inhibit their ability to enter and infect human cells

    Many exerts say that viruses can’t die because they are not alive in the first place, or are they? Viruses challenge our idea of what "living" means. Although the COVID-19 pandemic has killed thousands of people around the globe, viruses are crucial to life on earth. Many viruses, including HIV and hepatitis C, have thwarted vaccine developers. Learn how viruses can be destroyed to prevent infections and to preserve public health. 

    Viruses straddle the definition of life. Viruses lie somewhere between supra molecular complexes and very simple biological entities. Scientists are not sure whether viruses are living or non-living. So how do you get rid of viruses? 



    The scientific community uses the terms "inactivate" and "deactivate" when describing methods to prevent viruses from harming people. Viral inactivation is a process of enhancing viral safety in which viruses are intentionally “killed”. Consumer product manufacturers use the word "kill" when describing the antiviral disinfectants and antiviral hand sanitizers they market. Some purists postulate that you can not kill something that is not alive. This is not the time or place to debate the semantics of "killing viruses." In April of 2020, the entire world wants to know how to kill, destroy, inactivate - and simply get rid of viruses. The global Coronavirus pandemic has killed more than 30,000 people. Find out how to kill viruses to protect your health, save lives and minimize human suffering.



    Buy the best rated medical disinfectant solutions and sprays online at Buy common restaurant sanitizers, chlorine based sanitizers, sanitizing chemicals and quaternary based sanitizers online at LabAlley.comLearn about disinfectant efficacy protocols and studies here. Learn about FDA disinfectant efficacy here.

    A new therapeutic approach for suppressing seasonal influenza that involves synthetic phage shells that interfere with pathogen adhesion is immediately being tested for use on coronaviruses in response to the global COVID-19 pandemic. The research findings were published in Nature Nanotechnology on March 30, 2020. 

    List N: Products With Emerging Viral Pathogens And Human Coronavirus Claims For Use Against SARS-CoV-2

    The Best Ways To Inhibit, Inactivate And Treat Viruses

    What Does Not Kill The Coronavirus

    About EPA Approved Disinfectants

    Important Virus And Infection Protection Information For The Public



    Buy The Best Coronavirus Disinfectants Online | Soap, Bleach, Clorox Wipes, Hospital Grade Disinfectants, Concentrated Multipurpose Cleaners, Isopropyl And Ethyl Alcohol, Lysol Sprays And Hydrogen Peroxide At



    The Most Popular Virus Disinfectants And Antiviral Chemical Compounds Sold Online At

    Buy Virus Disinfectants Online Here Or By Phone: 512-668-9918

    If you have questions about ordering the best rated medical disinfectants, solutions, sprays, lab supplies and chemical ingredients to make your own Coronavirus disinfectants online here at or would like to place an order, call 512-668-9918 or email to talk with an Disinfectant Specialist. Lab Alley is a coronavirus disinfectant wholesale supplier and online retailer based in Austin, Texas.

    Use A 10% Discount Code To Order Virus Disinfectants

    Use this 10% discount code to buy virus disinfectants online or by phone in the U.S: LAB10OFF.  


    Types of Disinfectants With Examples | Microbiology with Sumi 

    The "Microbiology With Suma" YouTube channel cover various topics related to several branches of microbiology including virology


    U.S. Tariffs On Antiviral Chemicals And Sanitizers

    U.S. medical supply firms and online retailers of antiviral hospital grade sanitizers and coronavirus disinfectants such as, have been challenged by U.S. tariffs on imports of hand sanitizers and chemical disinfectants such as glutaraldehyde, used to fight the COVID-19 pandemic.

    Learn About The U.S. National Pandemic Strategy 

    These documents guide the United States’ preparedness and response in an influenza pandemic, with the intent of stopping, slowing or otherwise limiting the spread of a pandemic to the United States; limiting the domestic spread of a pandemic, mitigating disease, suffering and death; and sustaining infrastructure and mitigating impact to the economy and the functioning of society. 

    Copper’s Virus-Killing Powers Were Known Even to the Ancients 

    The SARS-CoV-2 virus endures for days on plastic or metal but disintegrates soon after landing on copper surfaces. Here’s why.

    How Can Light Kill Viruses?

    Laser therapy and light studies show that a virus can be killed with purple laser light. Learn more about how laser therapy can fight viruses.

    How To Inactivate Viruses

    There are a variety of methods to reduce virus, such as treatments with dry heat, steam or at pH 4. For virus inactivation in proteins, such as Factor VIII or van Willebrand factor, a solvent/detergent treatment is the method of choice to inactivate lipid-coat enveloped viruses. Read more here.

    Antimicrobial Products That Are Effective Against Norovirus (Norwalk-Like Virus)
    April 8, 2020

    For pesticide registration information, review this list from the EPA, "List G: EPA’s Registered Antimicrobial Products Effective Against Norovirus (Norwalk-Like Virus)". 

    Notes About This List

    • All EPA-registered pesticides must have an EPA registration number, which consists of a company number and a product number (e.g., 123-45). Alternative brand names have the same EPA registration number as the primary product.
    • When purchasing a product for use against a specific pathogen, check the EPA Reg. No. versus the products included on this list.
    • In addition to primary products, distributors may also sell products with formulations and efficacy identical to the primary products. Distributor products frequently use different brand names, but you can identify them by their three-part EPA registration number (e.g., 123-45-678, which represents a distributor product identical to the product example listed above, EPA Reg. No. 123-45).
    • If you would like to review the product label information for any of these products, please visit the EPA product label system.
    • Information about listed products is current as of the date on this list.
    • Inclusion on this list does not constitute an endorsement by EPA.

    View more information about EPA lists of registered antimicrobial products here. You may need a PDF reader to view some of the files on this page. See EPA’s About PDF page to learn more. 

    • Download List G: EPA’s Registered Antimicrobial Products Effective Against Norovirus (PDF)(6 pp, 130 K, March 4, 2020)
    • Contact the EPA about pesticide labels, to ask a question, provide feedback, or report a problem. 

    About The EPA Pesticide Product and Label System

    The Pesticide Product and Label System (PPLS) provides a collection of pesticide product labels (Adobe PDF format) that have been accepted by EPA under Section 3 of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). New labels were added to PPLS on April 08, 2020.

    • Search EPA Registration, Distributor Product, or Special Local Need Number Here
    • The EPA Registration Number (EPA Reg. No.) appears on all registered pesticides sold in the United States. It is usually found on the back panel of the label along with the detailed instructions for use.
    • Enter the company number (the first set of digits before the dash) to see all products marketed by that company or the entire number (including the dash) to view the label for a particular product.
    • To search by Special Local Need Number, please enter two-letter state abbreviations with or without 6 digit number (i.e. OH123456).
    • Search Buy Product or Alternative Brand Name: Enter the name of the product. As you type, options will be presented to you. Keep in mind that product names may vary, so if you don’t find the product you are looking for, try the EPA Registration Number Search.
    • Search By Company Name: Enter the name of the company. Some companies may have several divisions that manufacture and market pesticides products. You can select among these divisions using the drop-down list or choose the root of the company name (e.g., "Bayer" or "3M") to see products associated with all of the divisions.
    • Search By Company Number: Enter the company number. Please use digit without dash.
    • Search By Chemical Name (Active Ingredient): Enter the name of the chemical (Active Ingredients only) you are interested in. Because there are many naming conventions for chemicals, you can enter the common chemical name of the chemical or other variants, including scientific names or partial names. This search function will help guide you to products that contain that active ingredient.
    • Search By CAS Number Or PC Code: Enter the CAS Number or PC Code you are interested in. You may use the % wild card before and/or after your entry to enter a partial value.

    About Pesticide Labels

    Regulation Of Pesticide Labels

    Information On Pesticide Product Label Topics

    Get Help With Pesticide Label Issues

    Coronavirus In NY: Amazon Pilots Disinfectant Fog At Staten Island Warehouse
    April 7, 2020 | New York Post Inc told Reuters it is piloting the use of disinfectant fog starting on Tuesday at a warehouse on Staten Island, New York, within days of protests at the worksite over health concerns during the coronavirus pandemic. The world’s largest online retailer said it is testing the practice commonly used by airlines and hospitals to clean facilities further, on top of introducing temperature checks and masks for staff. Last week, 15 workers at the New York warehouse known internally as JFK8 protested to demand the building’s closure following a case of the coronavirus that was reported among staff. An additional demonstration took place Monday. Read more here.

    Guide to Local Production: WHO-recommended Handrub Formulations

    This Guide to Local Production of WHO-recommended Handrub Formulations is separated into two discrete but interrelated sections. Part A provides a practical guide for use at the pharmacy bench during the actual preparation of the formulation. Users may want to display the material on the wall of the production unit. Part B summarizes some essential background technical information and is taken from WHO Guidelines on Hand Hygiene in Health Care (2009). Within Part B the user has access to important safety and cost information and supplementary material relating to dispensers and distribution. Read more here.

    How To Make (And Use) A Disinfectant Against Coronavirus
    New York Times | April 7, 2020

    Here's a guide to working with sprays, wipes and a bleach-based solution to clean surfaces of the pathogen. 

    The coronavirus that causes Covid-19 may survive for several days on some surfaces. Estimates of its life span vary, but the virus can clearly hang around long enough to make disinfecting frequently touched surfaces a priority. Normally, disinfectants, like Lysol and Clorox wipes, are available and would do the trick in cleaning most surfaces of contagions, but many of these items have been widely out of stock across the United States. If you cannot find any of these products, you can make an effective homemade disinfectant from a mixture of water and bleach. Read more here.

    Guide to Local Production: WHO-recommended Handrub Formulations

    This Guide to Local Production of WHO-recommended Handrub Formulations is separated into two discrete but interrelated sections. Part A provides a practical guide for use at the pharmacy bench during the actual preparation of the formulation. Users may want to display the material on the wall of the production unit. Part B summarizes some essential background technical information and is taken from WHO Guidelines on Hand Hygiene in Health Care (2009). Within Part B the user has access to important safety and cost information and supplementary material relating to dispensers and distribution. Read more here.

    16 Safer Disinfectants To Use Against Coronavirus
    April 7, 2020

    Both the United States Environmental Protection Agency (EPA) and the American Chemistry Council have lists (here and here) of products that do one of two things. Each product either complies with the EPA’s emerging viral pathogen guidance, with demonstrated efficacy against viruses harder to kill than SARS-CoV-2 (the virus that causes COVID-19), or have demonstrated efficacy against another human coronavirus similar to SARS-CoV-2. Read more here.

    Guide to Local Production: WHO-recommended Handrub Formulations

    This Guide to Local Production of WHO-recommended Handrub Formulations is separated into two discrete but interrelated sections. Part A provides a practical guide for use at the pharmacy bench during the actual preparation of the formulation. Users may want to display the material on the wall of the production unit. Part B summarizes some essential background technical information and is taken from WHO Guidelines on Hand Hygiene in Health Care (2009). Within Part B the user has access to important safety and cost information and supplementary material relating to dispensers and distribution. Read more here.

    EPA Announced New Surface Disinfectant Products Added to List N in Effort to Combat COVID-19
    The National Law Review | Saturday, April 4, 2020

    On April 2, 2020, the U.S. Environmental Protection Agency (EPA) announced the addition of new surface disinfectants on EPA’s List N: Disinfectants for Use Against SARS-CoV-2 (List N) that may be used to combat SARS-CoV-2, the novel coronavirus that causes COVID-19. List N now contains 357 products. The webpage for List N also now has enhanced functionality to allow users to sort these products by surface type and use site. EPA states that it continues to expedite the review process for new disinfectants.

    Previously, all products on List N had to have either an EPA emerging viral pathogen claim or have demonstrated efficacy against another human coronavirus. EPA now has expanded List N to include products on EPA’s List G: EPA’s Registered Antimicrobial Products Effective against Norovirus and List L: Products Effective against the Ebola Virus, as these products also meet EPA’s criteria for use against SARS-CoV-2.

    EPA has updated List N to include the types of surfaces on which products can be used (e.g., hard or soft) and use sites (e.g., hospital, institutional or residential). Products applied via fogging or misting are now noted in the formulation column. This additional information allows the public to choose products that are appropriate for their specific circumstances.

    Additionally, EPA has updated the Frequently Asked Questions (FAQ) EPA has posted about disinfectants related to coronavirus. The FAQ update provides new information on pesticide safety, enforcement, and pesticide devices. It also includes enhanced explanations of why List N products are qualified for use against SARS-CoV-2 and how these products can be used most effectively.

    EPA states that it has continued to adapt its processes to ensure the supply of disinfectants keeps pace with demand. EPA recently announced additional flexibility that allows manufacturers of already-registered EPA disinfectants to obtain certain active and inert ingredients from any source of suppliers without prior approval by EPA. EPA also added 48 additional chemicals to its list of commodity inert ingredients. EPA states that this regulatory flexibility aims to help ease the production and availability of EPA-registered disinfectants.

    EPA also is expediting all requests for company numbers and establishment numbers to enable new pesticide-producing establishments to come online as quickly as possible. 

    Additional information on EPA’s efforts to address the novel coronavirus is available here.

    DIY Hand Sanitizers, Face Masks And Disinfecting Sprays | DIY Alternatives for When Stores Are Out of Coronavirus-Fighting Products
    April 4, 2020

    DIY hand sanitizers were the index species in the current wave of shelf extinctions, with usually plentiful supplies of Purell gel and similar products vanishing fast. Even without sanitizers, epidemiologists stress there is an exceedingly reliable alternative that works just as well: wash your hands with soap and water. Read more here.

    Do Air Purifiers Kill Viruses?

    An air purifier equipped with a HEPA (high-efficiency particulate air)-rated filter can technically capture a portion of airborne virus-sized particles. Once trapped, viruses cannot multiply on their own or remain infectious for long.  But NO air purifier can completely protect you from a virus. 

    CleanSmart Disinfectant Spray Mist Kills 99.9% Of Viruses, Bacteria, Germs, Mold And Fungus

    CleanSmart Disinfectant Spray Mist leaves no chemical residue and is great to clean and sanitize CPAP masks and parts. Simply spray, no rinsing, no wiping, air dry. Safe for food contact on counters and all appliances. Free of alcohol, ammonia, bleach, fragrances and dyes. 100% safe to spray and store around children and it breaks down to saline after use. Read more here.

    Chemical Disinfection Of Virus‐Contaminated Surfaces

    Chemical disinfection is widely practiced as a means of controlling and preventing the spread of infectious diseases. Although disinfection of bacteria has been widely studied, much less attention has been paid to the virucidal potential of commonly used disinfectants in spite of the low infective dose of many human pathogenic viruses. This review considers what is known about the disinfection of viruses and the virucidal properties of different classes of disinfectant chemicals. It focuses on virus disinfection from a practical viewpoint and also critically evaluates the testing techniques currently used for examining the efficacy of disinfectant products. Read more here.

    Factors In The Selection Of Surface Disinfectants For Use In A Laboratory Animal Setting

    Because surface disinfectants are an important means of pathogen control within laboratory animal facilities, these products must have an appropriate spectrum of antimicrobial activity. However, many other factors must also be considered, including effects on human health, environmental safety, and animal behavior. Aqueous solutions of sodium hypochlorite often are considered to be the ‘gold standard’ for surface disinfection, but these products can be corrosive, caustic, and aversive in odor. Read more here.

    ViruScrub Coronavirus Disinfectant, Mildewcide, Fungicide & Virucide Cleaner

    For use as a general, hospital, medical disinfectant, fungicide and virucide cleaner. Kills HIV, HBV and HCV on pre-cleaned hard, non-porous surfaces/objects previously soiled with blood/body fluids. This product can also be used as a non-acid toilet bowl and urinal disinfectant/cleaner. Cleans and disinfects shower rooms, locker room and other large, open areas with floor drains.

    Applicable Locations:
    Ideal for hospitals, medical and dental offices and clinics, healthcare facilities, nursing homes, day care centers and nurseries, kindergartens, and preschools, restaurants and bars, kitchens, cafeterias, fast food operations, supermarkets, convenience stores, retail and wholesale establishments. Institutional facilities, laboratories, factories, business and office buildings, restrooms, hotels and motels, schools, colleges, churches, athletic facilities and locker rooms, exercise facilities, gymnasiums. Read more here.

    Does Lysol Kill The Novel Coronavirus (SARS-CoV-2)?

    The EPA has established a list of disinfectants (List N) that meet their criteria for use against SARS-CoV-2, the cause of COVID-19. The following Lysol products are those that meet either the EPA Viral Emerging Pathogen Policy or have human coronavirus claims. Listed below are Lysol products with their EPA registration numbers.



    Buy EPA Certified Lysol Disinfectant Sprays To Kill Viruses 

    Buy EPA Certified Lysol Disinfecting Wipes To Kill Viruses 

    Buy EPA Certified Lysol Multi-Purpose Cleaners To Kill Viruses

    Buy Lysol Bathroom Cleaners To Kill Viruses

    Lysol Laundry Sanitizer To Kill Bacteria

    Please Refer To The CDC Website For Additional Information

    Coronavirus Pandemic Sparks Price Surge for Alcohol Used in Hand Sanitizer
    April 4, 2020 

    A leap in demand for isopropyl alcohol pushes prices to record highs in U.S. and Europe. A key ingredient in hand sanitizers and medical disinfectants has become hard to obtain, triggering its price to surge to an all-time high. Isopropyl-alcohol prices have more than tripled in the U.S. since March 10. Read more here.

    Protection For U.S. Consumers From Fraudulent Coronavirus Disinfectant Claims
    Posted on April 4, 2020 

    U.S. Environmental Protection Agency (EPA) Administrator Andrew Wheeler hosted an interactive telephone call with U.S. retailers and third-party marketplace platforms to discuss imposter disinfectant products and those that falsely claim to be effective against the novel coronavirus, SARS-CoV-2, the cause of COVID-19. The E.P.A. has threatened legal proceedings against vendors of bogus coronavirus (COVID-19) cleaners, disinfectants and sanitizers. While such products might not be harmful, they offer the public a dangerously false sense of protection that could deter social distancing and promote the spread of COVID-19. The federal government is asking online retailers to take unregistered products that falsely claim protection from coronavirus off the market. The EPA has continued to add new surface disinfectant products to List N in an effort to combat COVID-19. Any brand that claims to kill or repel bacteria or viruses should be tested and registered by the E.P.A. and with the federal government. 

    Herbal Plants And Natural Antiviral Agents Kill Viruses



    What Is A Virus?

    A virus is an infectious agent that can only replicate within a host organism. Viruses can infect a variety of living organisms, including bacteria, plants, and animals. Viruses are so small that a microscope is necessary to visualize them, and they have a very simple structure. When a virus particle is independent from its host, it consists of a viral genome, or genetic material, contained within a protein shell called a capsid. In some viruses, the protein shell is enclosed in a membrane called an envelope. Viral genomes are very diverse, since they can be DNA or RNA, single- or double-stranded, linear or circular, and vary in length and in the number of DNA or RNA molecules.

    The viral replication process begins when a virus infects its host by attaching to the host cell and penetrating the cell wall or membrane. The virus's genome is uncoated from the protein and injected into the host cell. Then the viral genome hijacks the host cell's machinery, forcing it to replicate the viral genome and produce viral proteins to make new capsids. Next, the viral particles are assembled into new viruses. The new viruses burst out of the host cell during a process called lysis, which kills the host cell. Some viruses take a portion of the host's membrane during the lysis process to form an envelope around the capsid.

    Following viral replication, the new viruses may go on to infect new hosts. Many viruses cause diseases in humans, such as influenza, chicken pox, AIDS, the common cold, and rabies. The primary way to prevent viral infections is vaccination, which administers a vaccine made of inactive viral particles to an unaffected individual, in order to increase the individual's immunity to the disease.

    Immunoprophylaxis Prevents Viral Diseases In Humans

    Immunoprophylaxis is the prevention of disease by administration of vaccines. Immunoprophylaxis against viral illnesses includes the use of vaccines or antibody-containing preparations to provide a susceptible individual with immunologic protection against a specific disease. Immunization against viral illnesses can be either active or passive. Read more here.

    What Is A Virucide?

    A virucide (pronounced /ˈvī-rə-ˌsīd/ and alternatively spelled viricide and viruscide) is any physical or chemical agent that deactivates or destroys viruses. This differs from an antiviral drug, which inhibits the proliferation of the virus.

    What Is A Virus, And How Does It Become A Danger To Human Life?
    By Molly Edmonds

    To understand viruses, it may help to consider the French emperor Napoleon Bonaparte. In the early 19th century, Bonaparte invaded much of Europe in order to establish French dominance over the continent. He's also known for being somewhat short in stature (however unfair that reputation may be).

    Like our idea of Napoleon, viruses are very small -- 100 times smaller than the average bacterium, so small that they can't be seen with an ordinary microscope. Viruses can only exert influence by invading a cell, because they're not cellular structures. They lack the ability to replicate on their own, so viruses are merely tiny packets of DNA or RNA genes enfolded in a protein coating, on the hunt for a cell they can dominate.

    Viruses can infect every living thing -- from plants and animals down to the smallest bacterium. For this reason, they always have the potential to be dangerous to human life. Still, they don't become truly treacherous until they infect a cell within the body. This infection can happen several ways: by air (thanks to coughing and sneezing), via carrier insects like mosquitoes, or by transmission of body fluids such as saliva, blood or semen.

    Once a virus infects a cell, it tries to take over its host completely, much as Napoleon spread the French influence with every country he fought. A virus lodged in a cell replicates and reproduces as much as possible; with each new replication, the host cell produces more viral material than it does normal genetic material. Left unchecked, the virus will cause the death of the host cell. Viruses will also spread to nearby cells and begin the process again.

    The human body does have some natural defenses against a virus. A cell can initiate RNA interference when it detects viral infection, which works by decreasing the influence of the virus's genetic material in relation to the cell's usual material. The immune system also kicks into gear when it identifies a virus by producing antibodies that bind to the virus and render it unable to replicate. The immune system also releases T-cells, which work to kill the virus. Antibiotics have no effect on viruses, though vaccinations will provide immunity.

    Unfortunately for humans, some viral infections outpace the immune system. Viruses can evolve much more quickly than the immune system can, which gives them a leg up in uninterrupted reproduction. And some viruses, such as HIV, work essentially by tricking the immune system. Viruses cause many diseases, including colds, measles, chicken pox, HPV, herpes, rabies, SARS and the flu. Though they're small, they pack a big punch -- and they can only sometimes be sent into exile.

    Demand For Antiviral Compounds And Bioactive Compounds Surges

    March 31, 2020

    COVID-19 is novel type of coronavirus that is affecting the entire planet. Viral infections such as COVID-19, continuously imperil worldwide public health because of a shortage of good antiviral therapeutics. Antiviral compounds are deployed against fatal viruses like HIV, Hepatitis C, Human herpesvirus 6 and Hepatitis B

    Antiviral compounds (AVCs) are a category of antimicrobial drugs used specially for treating viral infections by inhibiting the development of the viral pathogen inside the host cell. Review a list of antiviral drugs here. Several potent and selective antiviral agents against herpes virus infections have been developed. Research other methods for killing viruses here

    Some natural small molecules that could reduce the infectivity of SARS-CoV-2, possibly by inhibiting viral lipid-dependent attachment to host cells, are currently being studied. Companies such as R&D Systems (a brand of Bio-Techne) and Lab Alley sell antiviral compounds online. Firms such as BioGems (PeproTech brand), CPC Scientific, Sigma-Aldrich and R&D Systems sell antiviral compounds and products such as bioactive small molecules, small drug molecules and antimicrobial peptides (AMPs). Enveloped viruses can be killed by antimicrobial peptides.

    The four FDA-approved antiviral flu drugs recommended by CDC to treat the flu are oseltamivir (Tamiflu), zanamivir (Relenza), baloxavir marboxil (trade name Xofluza®) and peramivir (Rapivab). The FDA assists sponsors in the development of antiviral drugs and biological products. 

    A bioactive compound is a type of chemical found in small amounts in plants and certain foods. Studies are being conducted to evaluate the medicinal potential of bioactive compounds against COVID-19. Bioactive compounds have actions in the body that may promote good health. They are being studied in the prevention of diseases. Bioactive compounds are substances that have biological activity, related to their ability to modulate one or more metabolic processes. Bioactive compounds such as fatty acids have an effect on the body as a whole or specific tissues or cells. Bioactive compounds have a positive role in human health.

    Medium-chain saturated and long-chain unsaturated fatty acids are highly active against enveloped viruses. Bioactive compounds sold online at include saturated fatty acids such as stearic acid and palmitic acid

    Hydroxychloroquine For COVID-19 Treatment

    Doctors and pharmacists from more than half a dozen large healthcare systems in New York, Louisiana, Massachusetts, Ohio, Washington and California told Reuters they are routinely using hydroxychloroquine on patients hospitalized with COVID-19. At the same time, several said they have seen no evidence that the drug, used for years to treat malaria and autoimmune disorders, has any effect on the virus. Use of hydroxychloroquine has soared as the United States has quickly become the epicenter of the pandemic. The Food and Drug Administration has not approved hydroxychloroquine as a COVID-19 treatment, but the agency has provided an emergency use authorization for the anti-malarial drugs to be used in clinical trials or for hospitalized patients when a doctor deems it appropriate. Read more here.

    Chemical Inactivation Of Viruses

    Many viruses contain lipid or protein coats that can be inactivated by chemical alteration. Viral inactivation is different from viral removal because, in the former process, the surface chemistry of the virus is altered and in many cases the (now non-infective) viral particles remain in the final product. Read more here.

    Thermal Inactivation Of Viruses

    The thermal inactivation point (TIP) is defined as the lowest temperature required for complete inactivation of a virus in crude sap heated for 10 min. In the case of an unidentified virus, virus-containing sap is first exposed to temperatures at 10 °C intervals. Read more here.

    Inactivation Of Viruses By Germicides

    The inactivation of virus-contaminated nonporous inanimate surfaces was investigated using adenovirus type 8, a common cause of epidemic keratoconjunctivitis. A 10-μl inoculum of adenovirus was placed onto each stainless steel disk (1-cm diameter), and the inoculum was allowed to air dry for 40 min. Twenty-one different germicides (including disinfectants and antiseptics) were selected for this study based on their current uses in health care. Read more here.

    Pathogens Cause Infectious Diseases Like COVID-19

    Infectious diseases are caused by pathogens, which include bacteria, fungi, protozoa, worms, viruses, and even infectious proteins called prions. Many viruses, such as the Coronavirus (COVID-19), have a pathogenic relationship with their hosts – meaning they cause diseases ranging from a mild cold to serious conditions like severe acute respiratory syndrome (SARS). A pathogen is defined as an organism causing disease to its host, with the severity of the disease symptoms referred to as virulence. Pathogens are taxonomically widely diverse and comprise viruses and bacteria. Viruses work by invading the host cell, taking over its cellular machinery and releasing new viral particles that go on to infect more cells and cause illness.

    Chemistry, biochemistry and virology labs team up to look for action against deadly human viruses. There are anecdotal case reports of chloroquine helping COVID-19 patients. The World Health Organization has added chloroquine and hydroxychloroquine to a shortlist for clinical trials in Covid-19 patients. The antiviral drug, remdesivir is being used in new clinical trials for Covid-19. Repurposed drugs may help scientists fight the new coronavirus.

    All viruses are obligate pathogens as they are dependent on the cellular machinery of their host for their reproduction. Obligate pathogens are found among bacteria, including the agents of tuberculosis and syphilis, as well as protozoans (such as those causing malaria) and macroparasites. However, not all viruses are bad for you. Viruses matter to life. Some viruses can actually kill bacteria, while others can fight against more dangerous viruses. So like protective bacteria (probiotics), we have several protective viruses in our body. First seen as poisons, viruses today are thought of as being in a gray area between living and nonliving: they cannot replicate on their own but can do so in truly living cells and can also affect the behavior of their hosts profoundly. Repurposed drugs may help scientists fight the new coronavirus.

    How To Control Viruses

    Some claim that viruses can not be killed because they are not alive, but nobody questions that some viruses need to be controlled through inactivation. Many viral diseases are controlled by reducing exposure to the virus by (1) eliminating nonhuman reservoirs, (2) eliminating the vector, and (3) improving sanitation.

    For most viral infections, treatments can only help with symptoms while you wait for your immune system to fight off the virus. Antibiotics do not work for viral infections. There are antiviral medicines to treat some viral infections. Vaccines can help prevent you from getting many viral diseases. Learn how to inactivate viruses below.

    Viral Inactivation

    Viral inactivation renders viruses inactive, or unable to infect. The novel virus is one of the easiest virus types to deactivate. Viral inactivation effectively kills or destroys viruses for all practical purposes. Sodium hypochlorite is effective in killing viruses, including influenza virus. Viral inactivation is important when manufacturing human blood plasma products.

    The main idea behind viral processing is to stop the viruses in a given sample from contaminating the desired product. The two most widely used methods of viral processing are viral removal and viral inactivation. The former is a method in which all viruses are simply removed from the sample completely. The latter method is one in which the viruses may remain in the final product, but in a non-infective form. These techniques are used widely in the food and blood plasma industries, as those products can be harmed by the presence of viral particles. Some of the more common viruses removed by these methods are the HIV-1 and HIV-2 viruses; hepatitis A, B, and C; and parvoviruses.

    How To Render Viruses Inactive 

    Viral inactivation renders viruses inactive, or unable to infect. Many viruses contain lipid or protein coats that can be inactivated by chemical alteration. Viral inactivation is different from viral removal because, in the former process, the surface chemistry of the virus is altered and in many cases the (now non-infective) viral particles remain in the final product. Rather than simply rendering the virus inactive, some viral inactivation processes actually denature the virus completely. Viral inactivation is used widely in the blood plasma industry.

    In order to achieve inactivation of the viruses in the sample, it is necessary to perform "special" purification processes that will chemically alter the virus in some way. Some of the more widely used processes are as follows:

    In some cases viral inactivation is not a viable removal alternative because even the denatured or otherwise inactivated viral particles can have deleterious effects on the process stream or the product itself.

    Solvent/Detergent (S/D) Inactivation Of Viruses 

    This process, developed by the New York Blood Center, is the most widely used viral inactivation method to date. It is predominantly used in the blood plasma industry, by over 50 organizations worldwide and by the American Red Cross. This process is only effective for viruses enveloped in a lipid coat, however. The detergents used in this method interrupt the interactions between the molecules in the virus's lipid coating. Most enveloped viruses cannot exist without their lipid coating so are destroyed when exposed to these detergents. Other viruses may not be destroyed but they are unable to reproduce rendering them non-infective. The solvent creates an environment in which the aggregation reaction between the lipid coat and the detergent happen more rapidly. The detergent typically used is Triton X-100, which is made with Polyethylene glycol (PEG), an eco-friendly solvent.

    This process has many of the advantages of the "traditional" removal techniques. This process does not denature proteins, because the detergents only affect lipids and lipid derivatives. There is a 100% viral death achieved by this process and the equipment is relatively simple and easy to use. Equipment designed to purify post-virus inactivated material would be necessary to guard against contamination of subsequent process streams.

    S/D treatment utilizes readily available and relatively inexpensive reagents, but these reagents must be removed from the product prior to distribution which would require extra process steps. Because this process removes/inactivates the lipid coating of a virus, viruses without any sort of lipid envelope will be unaffected. There is also no inactivation effect by the buffers used in this process.

    How To Use Pasteurization To Kill Viruses

    Inactivation of viruses by means of pasteurization can be very effective if the proteins that you are trying to protect are more thermally resistant than the viral impurities with which they are in solution. Some of the more prominent advantages of these types of processes are that they require simple equipment and they are effective for both enveloped and non-enveloped viruses. Because pasteurization involves increasing the temperature of solution to a value that will sufficiently denature the virus, it does not matter whether the virus has an envelope or not because the envelope alone cannot protect the virus from such high temperatures. However, there are some proteins which have been found to act as thermal stabilizers for viruses. Of course, if the target protein is not heat-resistant, using this technique could denature that target protein as well as the viral impurity. Typical incubation lasts for 10 hours and is performed at 60°C.

    How To Use Acidic pH To Inactivate Viruses

    Some viruses, when exposed to a low pH, will denature spontaneously. Similar to pasteurization, this technique for viral inactivation is useful if the target protein is more resistant to low pHs than the viral impurity. This technique is effective against enveloped viruses, and the equipment typically used is simple and easy to operate. This type of inactivation method is not as effective for non-enveloped viruses however, and also requires elevated temperatures. So in order to use this method, the target protein must be resistant to low pHs and high temperatures which is unfortunately not the case for many biological proteins. Incubation for this process typically occurs at a pH of 4 and lasts anywhere between 6 hours and 21 days.

    How To Use Ultraviolet (UV) Light To Inactivate Viruses

    UV rays can damage the DNA of living organisms by creating nucleic acid dimers. However, the damages are usually not important due to low penetration of UVs through living tissues. UV rays can be used, however, to inactivate viruses since virus particules are small and the UV rays can reach the genetic material, inducing the dimerisation of nucleic acids. Once the DNA dimerised, the virus particules cannot replicate their genetic material which prevent them from spreading. UV light in combination with riboflavin has been shown to be effective in reducing pathogens in blood transfusion products. Riboflavin and UV light damages the nucleic acids in viruses, bacteria, parasites, and donor white blood cells rendering them unable to replicate and cause disease.

    Virus Removal 

    This overarching process, which has come to be known simply as virus removal, is one in which all of the viruses in a given sample are removed by traditional extraction or [full energy] methods. Some of the more prominent methods include:

    These extraction processes are considered "traditional processes" because they do not chemically affect the virus in any way; they simply remove it physically from the sample.

    How To Use Nanofiltration To Remove Viruses 

    Virus removal processes using nanofiltration techniques remove viruses specifically by size exclusion. This type of process is typically used for parvoviruses and other viruses containing a protein coat. A typical HIV virion is 180 nm and a typical parvovirus can vary between 15 and 24 nm, which is very small. One great advantage of filtration, as opposed to methods involving extremes of temperature or acidity, is that filtration will not denature the proteins in the sample. Nanofiltration is also effective for most types of proteins. Since it is not chemically selective, no matter what the surface chemistry of the viral particle is, viral removal processes using nanofiltration techniques will still be effective. Another great advantage of this technique is its ability to be performed on a lab scale and then effectively scaled up to production standards. It is important to consider, however, the fact that the level of removal of the viruses is dependent on the size of the pores of the nanofilter. In some cases, very small viruses will not be filtered out. It is also necessary to consider the possible effects of pressure and flow rate variation.

    Some of the filters used for to perform these types of processes are Planova 15N, Planova 20N, BioEX, VAG - 300, Viresolve 180, Viresolve 70TM, and the Virosart range.

    How To Use Chromatography To Remove Viruses

    Chromatographic methods of removing viruses are great for purifying the protein and are also effective against all types of viruses, but the level of virus removal is dependent on the column composition and the reagents that are used in the process. It is also worthy to note that the effectiveness of this process can vary greatly between viruses and that the efficiency of the process can change based on the buffer that is used. Sanitation between batches is also a concern when performing this procedure.

    Viral Inactivation Low pH

    Viral inactivation by low pH has been reliably demonstrated to inactivate more than >4log10 of large enveloped viruses (e.g., X-MuLV) in several commercial purification processes. This clearance step can be applied to monoclonal antibodies that have purification process steps that include a low pH step. Read more here.

    Cupric And Ferric Ions Inactivate HIV

    Human immunodeficiency virus (HIV-1) was inactivated by either cupric or ferric ions when the virus was free in solution and also 3 hr after cell infection. Fifty percent inactivation of cell-free HIV was achieved with Cu(II) at a concentration between 0.16 and 1.6 mM, or by 1.8 to 18 mM Fe(III). Thus, the dose to inactivate 50% of infectious HIV (D50) by Cu(II) or Fe(III) is higher than that reported for glutaraldehyde (0.1 mM); between the D50 reported for sodium hypochlorite (1.3 mM) and sodium hydroxide (11.5 mM), and significantly lower than that required for HIV inactivation by ethanol (360 mM). Treatment of infected cells for 30 min at 20 degrees C with 6 mM Cu(II) or Fe(III) completely inhibited the formation of syncytia and the synthesis of virus-specific p24 antigen in HIV-infected cells, while still preserving cell viability. The virucidal properties of cupric and ferric ions could be exploited for the development of novel virucidal formulations efficient against HIV.

    Virucidal Efficacy Of A Disinfectant Solution Composed of Citric acid, Malic Acid And Phosphoric Acid Against Avian Influenza Virus

    Highly pathogenic avian influenza virus (HPAIV) damages vital organs and tissues, frequently leading to death in birds, and causes serious economic losses in the poultry industry. In addition, HPAIV can infect humans and other mammals, often with fatal outcomes. In this study, the virucidal efficacy of Clean-Zone®, which contains citric acid, malic acid and phosphoric acid, against avian influenza virus (AIV, H9N2) was investigated. Virucidal efficacy was determined by examining the viability of AIV after contact with the disinfectant in the allantoic membrane of chicken embryos. The disinfectant and AIV were reacted under hard water (HW) and organic matter suspension (OM) condition. AIV was inactivated with 200- and 50-fold dilutions of the disinfectant under HW and OM conditions, respectively. As the disinfectant, Clean-Zone®, has a virucidal efficacy against AIV, it can be used to prevent the spread of animal viral diseases. It is possible that the virucidal efficacy of Clean-Zone® was superior to citric acid alone because the interaction of citric acid, malic acid and phosphoric acid has a synergistic effect against AIV. Read more here.

    Quinine And Synthetic Derivatives Are Antiviral, Bactericidal, Antibacterial, Antimicrobial And Antimalarial

    • Quinine sulfate (Quinine Hydrogen Sulfate) is a organic sulfate salt obtained from guanethidine and sulfuric acid in a 2:1 ratio. It has a role as an antimalarial. It contains a quinine and a quinine(1+).
    • Chloroquine is a semisynthetic derivative of quinine.
    • Currently in 2020, the synthetic form of quinine, Chloroquine is being researched and studied to see if it can effectively treat infectious diseases such as coronavirus (COVID-19). 
    • Some scientists theorize that chloroquine interferes with ACE2 receptor glycosylation thus preventing SARS-CoV-2 binding to target cells. The sythetic form of quinine, chloroquine has been shown to improve the clinical outcome of patients infected by SARS-CoV-2 (COVID-19)
    • FDA approved drugs such as quinine sulfate inhibit Dengue virus (DENV) replication.

    4 Log Inactivation Of Viruses

    Inactivation is a function of the disinfectant concentration and the amount of time the water spends in contact with the disinfectant before the first service connection, which is called “contact time” or CT. The credit to remove or inactivate 99.99% of virus is called “4-log virus credit.” Read more here.

    Inactivation Of Avian Influenza Virus Using Common Detergents And Chemicals

    Six disinfectant chemicals were tested individually for effectiveness against low pathogenic avian influenza virus (LPAIV) A/H7N2/Chick/MinhMa/04. The tested agents included acetic acid (C2H4O2), citric acid (C6H8O7), calcium hypochlorite (Ca(ClO)2), sodium hypochlorite (NaOCl), a powdered laundry detergent with peroxygen (bleach), and a commercially available iodine/acid disinfectant. Four of the six chemicals, including acetic acid (5%), citric acid (1% and 3%), calcium hypochlorite (750 ppm), and sodium hypochlorite (750 ppm) effectively inactivated LPAIV on hard and nonporous surfaces. The conventional laundry detergent was tested at multiple concentrations and found to be suitable for inactivating LPAIV on hard and nonporous surfaces at 6 g/L. Only citric acid and commercially available iodine/acid disinfectant were found to be effective at inactivating LPAIV on both porous and nonporous surfaces.

    Use Benzalkonium Chloride To Deactivate Viruses

    Benzalkonium chloride (as Roccal or Zephiran) was found to inactivate influenza, measles, canine distemper, rabies, fowl laryngotracheitis, vaccinia, Semliki Forest, feline pneumonitis, meningopneumonitis, and herpes simplex viruses after 10 minutes of exposure at 30 C or at room temperature. Read more here

    Type A influenza viIrus was inactivated by concentrations of benzalkoniunm chloride as low as 0.025 mng/iml. Measles and canine distemper viruses were also sensitive to the quaternary. Feline pneuiinonitis and miieningopneumionitis agents were inactivated by benzalkonium chloride after 10 minutes of exposure at room temperature. Rabies, fowl laryngotracheitis, Seliliki Forest, and herpes simplex viruses were rapidly inactivated by low concentrations of benzalkonium chloride. Review more information on the virucidal activity of benzalkonium chloride for 13 viruses here.

    Is Benzalkonium Chloride An Antiviral?

    Benzalkonium Chloride Demonstrates Concentration-Dependent Antiviral Activity Against Adenovirus In Vitro. Benzalkonium chloride (BAK) is a common preservative in ophthalmic medications and is the active ingredient in some skin disinfectants and hand sanitizers. Read more here.

    Inactivation Of Viruses By Aziridines

    Ethyleneimine (EI) and N-acetylethyleneimine (AEI) have been shown to inactivate viruses belonging to most of the families described by the International Committee for the Taxonomy of Viruses. The mechanism by which they inactivate the viruses has not been established. Read more here.

    The Effect Of Cicloxolone Sodium On The Replication In Cultured Cells Of Adenovirus Type 5, Reovirus Type 3, Poliovirus Type 1, Two Bunyaviruses And Semliki Forest Virus

    The effect of cicloxolone sodium (CCX) on the replication of typical representatives of different virus families [adenovirus type 5 (Ad-5), reovirus type 3 (Reo-3), Bunyamwera and Germiston viruses, poliovirus type 1 (Polio-1) and Semliki Forest virus (SFV)] in tissue culture was investigated. The Golgi apparatus inhibitor monensin (Mon) and CCX were shown to have analogous effects on some aspects of virus replication. Although the Mon-like effect of CCX played no role in the antiviral activity against Ad-5, Reo-3 or Polio-1, it could entirely account for the antiviral activity against the Bunyamwera and Germiston viruses, for which inhibition of glycoprotein processing was responsible for the antiviral activity. In the case of SFV, the Mon-like activity of CCX caused cytoplasmic assembly of fully infectious SFV within vacuoles and thus impaired virus release without altering total infectious virus yield. Fewer Ad-5 and Reo-3 progeny were produced in the presence of the drug. CCX had a dose-dependent biphasic effect on the particle:p.f.u. ratio of the Reo-3 yield. At low CCX concentration (less than 50 microM) the virus yield contained poor quality, non-infectious virus, but at higher CCX concentration (greater than or equal to 100 microM) low quality virus could no longer be successfully assembled. We conclude that the antiviral effect can be manifested in three ways: (i) by a reduction in the virus particle yield produced; (ii) by a loss of quality (relative infectivity); (iii) by a virucidal effect of the drug. We have previously defined three CCX sensitivity classes. Mechanisms (i), (ii) and (iii) operate against viruses belonging to class CCXs-1 [herpes simplex virus (HSV) type 1, HSV-2 and vesicular stomatitis virus], but essentially only (i) and (ii) affect Reo-3 (CCXs-2), whereas (i) and possibly (iii) affect Ad-5 (CCXs-2). In the case of SFV (CCXs-3) none of these mechanisms operate, but relocation of assembled virus is found.

    Novel Amphiphilic Compounds Effectively Inactivate The Vaccinia Virus

    Recent studies demonstrated the ability of artificial ribonucleases (aRNases, small organic RNA cleaving compounds) to inactivate RNA-viruses via the synergetic effect of viral RNA cleavage and disruption of viral envelope. Herein, we describe the antiviral activity of aRNases against DNA-containing vaccinia virus: screening of aRNases of various structures revealed that amphiphilic compounds built of positively charged 1,4-diazabicyclo[2.2.2] octane substituted at the bridge nitrogen atoms with aliphatic residues efficiently inactivate this virus. The first stage was the destruction of viral membrane and structure of surface proteins (electron microscopy data). Thus, 1,4-diazabicyclo[2.2.2] octane-based aRNases are novel universal agents inactivating both RNA- and DNA-containing viruses. Read more here.

    Magnesium-mediated Reversal of the Apparent Virucidal Effect of Ascorbic Acid or Congo Red Reacted In Vitro With The Human Immunodeficiency Virus 

    The mechanism of in vitro inactivation of cell-free human immunodeficiency virus (CFHIV) with ascorbic acid (M) or Congo red (CR) was investigated with specific regard to the impact of an excess of magnesium ions on the viral inactivation. Quadruplicate reaction mixtures containing CFHIV were mixed with a virus-inactivating dose of 500 micrograms/ml ascorbic acid in RPMI medium devoid of fetal bovine serum and incubated for 3 h at 4 degrees C in two parallel sets of experiments. AA-free CFHIV and virion-free AA were included in each experiment as the positive and negative controls, respectively. After adding 10(6) MT2 cells to capture the surviving virons, the mixtures were incubated for 1 h at 37 degrees C. The cells from the first set were washed three times with Hanks balanced salt solution (HBSS) only, and those from the second set were washed with HBSS fortified with MgCl2 (1.0 mg/ml). Similarly, inactivation of CFHIV by increasing amounts of CR ranging between 12.5-100 micrograms/ml was also tested for the effect of MgCl2, except that (i) the assay was performed in subdued light, (ii) CFHIV-CR mixtures were incubated at 37 degrees C for 1 h in the dark and (iii) H9 cells were used instead of the MT-2 cells to capture the surviving virions in the test mixtures. The cells were cultured in RPMI with 20% FBS for 5 days at 37 degrees C. The absence of p24 antigen in the culture supernatant of MT2 or H9 cells indicated HIV inactivation by AA or CR, respectively. Remarkably, the cultured cells that were washed with HBSS + MgCl2 consistently expressed p24 antigen at levels comparable with those from the untreated virus control. Therefore, the apparent in vitro inactivation of CFHIV by either AA or CR was reversible as validated by washing of the cells with HBSS + MgCl2 following capture of the virions from CFHIV-AA or CFHIV-CR inactivation mixtures. These observations underscore the need for including extra magnesium ions as a control in validating various protocols used for assessing the in vitro virucidal activity of reverse transcriptase inhibitors, membrane binding dyes, or other candidate chemical agents.

    Glycerol Inactivates Viruses

    Effect of glycerol on intracellular virus survival: implications for the clinical use of glycerol-preserved cadaver skin. 

    Glycerol has long been used for the preservation of skin allografts. The antimicrobial activity of glycerol has not been fully documented. This paper reports the results of an investigation of a model studying the effect of glycerol on the inactivation of intracellular viruses. Two viruses--herpes simplex type I (HSV-1) and poliovirus--were cultured within human dermal fibroblasts. These intracellular viruses were incubated with 50 per cent, 85 per cent and 98 per cent glycerol at 4 degrees C and 20 degrees C for 4 weeks. Each week, the cultures in glycerol and controls in fibroblast maintenance medium were assayed for virus infectivity by examining the ability of harvested viruses to infect further fibroblasts. At 4 degrees C, 85 per cent glycerol could not fully inactivate intracellular HSV-I or poliovirus even after 4 weeks; 98 per cent glycerol inactivated intracellular HSV-I (after 3 weeks) but could not fully inactivate intracellular poliovirus after 4 weeks. At 20 degrees C, 85 per cent glycerol inactivated intracellular HSV-I (within 1 week) but could not fully inactivate intracellular poliovirus after 4 weeks; 98 per cent glycerol inactivated intracellular HSV-I (within 1 week) and inactivated intracellular poliovirus (after 2 weeks). It is suggested that, on the basis of this study, glycerol can reduce intracellular virus infectivity but that its effects are very dependent on concentration, time and temperature such that we would recommend that allograft skin be exposed to 98 per cent glycerol for a minimum of at least 4 weeks at a minimum temperature of 20 degrees C before clinical use.

    Monolaurin, also known as glycerol monolaurate (GML), glyceryl laurate or 1-lauroyl-glycerol, is a monoglyceride. It is the mono-ester formed from glycerol and lauric acid. Monolaurin is known to inactivate lipid-coated viruses by binding to the lipid-protein envelope of the virus, thereby preventing it from attaching and entering host cells, making infection and replication impossible. Other studies show that Monolaurin disintegrates the protective viral envelope, killing the virus.Monolaurin has been studied to inactivate many pathogens including Herpes simplex virus and Chlamydia trachomatis. Read more here.

    Inactivation Of Enveloped Viruses In Human Bodily Fluids By Purified Lipids

    Antimicrobial lipids are found in mucosal secretions and are one of a number of nonimmunologic and nonspecific protective factors found at mucosal surfaces. Lipids can inactivate enveloped viruses, bacteria, fungi, and protozoa. Lipid-dependent antimicrobial activity at mucosal surfaces is due to certain monoglycerides and fatty acids that are released from triglycerides by lipolytic activity. Medium chain length antiviral lipids can be added to human blood products that contain HIV-1 and HIV-2 and reduce the cell-free virus concentration by as much as 11 log10 TCID50/ml. The presence of lipids does not interfere with most clinical assays performed on human blood samples. Antimicrobial lipids can disrupt cell membranes and therefore lyse leukocytes which potentially carry virus. Genital mucosal epithelial cells should be protected from damage by the mucous layer. Preliminary studies indicate that lipids decrease sperm motility and viability suggesting that lipids may potentially be used as combination spermicidal and virucidal agents.

    Inactivation Of Enveloped Viruses And Killing Of Cells By Fatty Acids And Monoglycerides

    Lipids in fresh human milk do not inactivate viruses but become antiviral after storage of the milk for a few days at 4 or 23 degrees C. The appearance of antiviral activity depends on active milk lipases and correlates with the release of free fatty acids in the milk. A number of fatty acids which are normal components of milk lipids were tested against enveloped viruses, i.e., vesicular stomatitis virus, herpes simplex virus, and visna virus, and against a nonenveloped virus, poliovirus. Short-chain and long-chain saturated fatty acids had no or a very small antiviral effect at the highest concentrations tested. Medium-chain saturated and long-chain unsaturated fatty acids, on the other hand, were all highly active against the enveloped viruses, although the fatty acid concentration required for maximum viral inactivation varied by as much as 20-fold. Monoglycerides of these fatty acids were also highly antiviral, in some instances at a concentration 10 times lower than that of the free fatty acids. None of the fatty acids inactivated poliovirus. Antiviral fatty acids were found to affect the viral envelope, causing leakage and at higher concentrations, a complete disintegration of the envelope and the viral particles. They also caused disintegration of the plasma membranes of tissue culture cells resulting in cell lysis and death. The same phenomenon occurred in cell cultures incubated with stored antiviral human milk. The antimicrobial effect of human milk lipids in vitro is therefore most likely caused by disintegration of cellular and viral membranes by fatty acids. Studies are needed to establish whether human milk lipids have an antimicrobial effect in the stomach and intestines of infants and to determine what role, if any, they play in protecting infants against gastrointestinal infections. Read more here.

    Azodicarbonamide Inhibits HIV-1 Replication By Targeting The Nucleocapsid Protein

    Nucleocapsid p7 (NCp7) proteins of human immunodeficiency virus type 1 (HIV-1) contain two zinc binding domains of the sequence Cys-(X)2-Cys-(X)4-His-(X)4-Cys (CCHC). The spacing pattern and metal-chelating residues (3 Cys, 1 His) of these nucleocapsid CCHC zinc fingers are highly conserved among retroviruses. These CCHC domains are required during both the early and late phases of retroviral replication, making them attractive targets for antiviral agents. Toward that end, we have identified a number of antiviral chemotypes that electrophilically attack the sulfur atoms of the zinc-coordinating cysteine residues of the domains. Such nucleocapsid inhibitors were directly virucidal by preventing the initiation of reverse transcription and blocked formation of infectious virus from cells through modification of CCHC domains within Gag precursors. Herein we report that azodicarbonamide (ADA) represents a new compound that inhibits HIV-1 and a broad range of retroviruses by targeting the the nucleocapsid CCHC domains. Vandevelde et al. also recently disclosed that ADA inhibits HIV-1 infection via an unidentified mechanism and that ADA was introduced into Phase I/II clinical trials in Europe for advanced AIDS. These studies distinguish ADA as the first known nucleocapsid inhibitor to progress to human trials and provide a lead compound for drug optimization.

    Effective Inactivation Of Human Immunodeficiency Virus With Chlorhexidine

    Antiseptics Containing Detergents And Alcohol The antiseptics 4% chlorhexidine gluconate detergent formulation containing 4% isopropyl alcohol (Hibiclens/Hibiscrub) and 0.5% chlorhexidine gluconate in 70% isopropyl alcohol with emollients (Hibistat/Hibisol) efficiently inactivated human immunodeficiency virus (HIV) produced in cell culture within 15 seconds. These antiseptics were completely effective at 1:100 and 1:5 dilutions, respectively. Therefore, use of these products according to the manufacturer's instructions (i.e. undiluted) for routine disinfection of hands following contact with HIV-contaminated materials, as well as immediate disinfection of abrasions or cuts exposed to HIV, should have significant protective effects.

    How Viruses Work and How to Prevent and Eliminate Them Naturally
    Urology of Virginia | 03-13-2020

    We have identified more than 2,000 viruses, though only 10% infect humans. Scientists used to think human viruses do not affect animals and animal viruses do not affect humans, but we now know that viruses not only jump species, sometimes they combine to create new strains. New strains can present a clear threat to human survival.

    In 1918 the Spanish flu pandemic was a global killer. Estimates of the dead range from 20-100 million, up to 5% of the population–all within one year. Unlike previous flu pandemics and epidemics, this flu strain killed healthy adults, whereas most flu strains targeted children, the elderly, and the infirmed. More people died in this one-year pandemic than the four years of the bubonic plague.

    We often hear that many dangerous strains of influenza begin in China. This belief is based on the dense population of humans living in close proximity to high populations of animals. Many dangerous viral strains have been found to originate in China jumping from birds or pigs to the human population. Birds alone have been found to carry as many as 15 viral strains.

    A virus is a pathogenic, parasitic organism that isn’t classified as being alive, since a cell is an essential to our definition of life. A virus has no cell membrane, no metabolism, no respiration and cannot replicate outside of a living cell. A virus is a creepy half-live, single strand or double strand of DNA or RNA or both, looking for a cell to invade. Once inside, it reprograms the cell with its DNA or RNA and multiplies on mass, bursting through the cell with a thousand or more new virus strands seeking new cells to invade. RNA viruses mutate more easily than DNA viruses. (SARS, bird flu, West Nile virus, swine flu, hepatitis, measles, polio, yellow fever, and Ebola are among the many RNA viruses).

    If two viruses invade the same cell (a bird virus and a human virus, for instance) their DNA can combine to form a new virus, a potentially virulent one. The same is true if two animal viruses combine and jump species to humans.

    Viruses have two life cycles: the lytic cycle and the lysogenic cycle. In the lytic cycle, the virus focuses on reproduction. It invades a cell, inserts its DNA and creates thousands of copies of itself, bursts through the cell membrane, killing the cell, and each new viral strand invades new cells replicating the process.

    In the lysogenic cycle, viruses remain dormant within its host cells. The virus may remain dormant for years. Herpes and chickenpox are good examples. (Chicken pox can cause shingles in later life when the dormant virus reactivates.)

    Our bodies fight off invading organisms, including viruses, all the time. Our first line of defense is the skin, mucous, and stomach acid. If we inhale a virus, mucous traps it and tries to expel it. If it is swallowed, stomach acid may kill it. If the virus gets past the first line of defense, the innate immune system comes into play. The phagocytes wage war and release interferon to protect surrounding cells. If they cannot destroy the invading force, the phagocytes call the lymphocytes into play.

    Our lymphocytes, T cells and B cells, retain a memory of any previous infection that was serious enough to bring them into the battle. Antibodies were formed and the body knows how to fight any infection it recognizes. (This is how vaccinations work. The body has fought a similar infection). But viruses can mutate, sometimes so much that they body cannot recognize them as a similar infection they fought in the past. They can also be so fast acting, they can kill before the lymphocytes are brought into play.

    Antiviral medications do not directly kill the virus; they trap it within the cell, keeping it from reproducing. The only catch is that the anti-viral has to be taken with 48 hours of symptom onset or it doesn’t work.

    Antibiotics don’t kill viruses. They kill bacteria, not viruses. And they kill good bacteria that we need to keep our gut in balance. Taking antibiotics when you have a viral infection can cause an immediate overgrowth of Candida, giving the immune system an additional system-wide infection to deal with when it needs all of its resources to fight a viral infection.

    Conventional treatment is supportive treatment–fluids, medications for symptoms (such as asthma medication), but no medications have ever been developed to kill the virus itself.

    Don’t panic. Most viruses don’t affect us. But still, it brings up a point. Viral infections are a symptom of a weak immune system. Your immune system is wholly dependant on your gut health. A sick gut has an abundance of fungi and other pathogens, and a healthy gut has a wide variety of beneficial bacteria. The supplements listed below are a half measure. A healthy nutrient dense diet, a healthy lifestyle, and a body void of as many toxins as possible is the first and foremost defense. If you want to skip the shortcuts and truly fortify your immune system, read the following articles:

    A healthy immune system begins in the gut with a healthy balance of beneficial bacteria. For far too many Americans, Candida overgrowth compromises the immune system, as it is constantly fighting the battle to keep Candida in control.

    If you do become ill, DO NOT feed the virus or the Candida with sugar. Yes, you need to drink a lot of fluids, but don’t drink sodas and sugary juices at this time. Cranberry lemonade sweetened with stevia is a good choice. Try it warm or cold.

    Gargle. Gargle. Gargle. Gargling lowers the viral load, leaving your body with fewer invaders to replicate. Gargle with organic apple cider vinegar. Even better, sip on this Mother Earth Organic Root Cider. Cold’s and flu often start in the throat or the nasal cavities. At the first sign of a sore throat or sinus infection, sip on the root cider! If you don’t have it, use apple cider vinegar.

    Also, remember that a fever is one of nature’s means to fight infection. Of course, you don’t want it to get too high (higher than 102) and drink plenty of fluids to prevent dehydration.

    Vitamin A, vitamin D, vitamin E, and vitamin C are all vital nutrients for the immune system. If you take high doses of vitamin C to fight a virus, remember that you should not abruptly stop taking vitamin C. You should titrate down. Vitamin C is needed by the immune system to make interferon, which the immune system produces to protect healthy cells from viral invasion.

    Zinc has been proven to be effective against the common cold and to be effective as a topical treatment for herpes sores. It is believed to be effective due to preventing replication of the virus. The immune system needs selenium to work properly and to build up the white blood cell count.

    Berberine is an alkaloid compound found in several different plants, including European barberry, goldenseal, goldthread, Oregon grape, Phellodendron, and Coptis chinensis. It has antibacterial, anti-inflammatory, antiviral, anti-parasitic, and immune-enhancing properties. It’s been proven effective against a vast array of bacteria, protozoa, and fungi. It can be used topically on cuts and other wounds, and it’s perhaps most commonly used to treat gastrointestinal issues.

    Probiotics are always helpful in maintaining gut health, especially when the body is under a viral attack that involves the digestive system. Probiotic foods and drinks without added sugar can help maintain a healthy balance of bacteria.

    Garlic is anti-viral, anti-fungal, and antibacterial. You can take garlic in a tonic or if you can handle it, chew raw garlic. It not only will help fight the virus, it will help kill any secondary infections trying to take root.

    Echinacea not only supports the immune system, it also has been proven to reduce the severity and duration of viral infections.

    Colloidal silver is believed to interfere with the enzymes that allow viruses (bacteria and fungi as well) to utilize oxygen.

    A double-blind trail showed elderberry extract’s ability to reduce symptoms of influenza and speed recovery. It also showed elderberry’s ability to enhance immune response with higher levels of antibodies in the blood. It is believed to inhibit a virus’s ability to penetrate healthy cells and protect cells with powerful antioxidant S. Elderberry has also been shown to inhibit replication in four strains of herpes viruses and reduce infectivity of HIV strains.

    The flavonoids in green tea are believed to fight viral infections by preventing the virus from entering host cells and by inhibiting replication.

    Though double-blind clinical trials are needed, olive leaf extract has been shown to inhibit replication of viruses. In one study, 115 of 119 patients had a full and rapid recovery from respiratory tract infections while 120 of 172 had a full and rapid recovery from viral skin infections such as herpes.

    Pau d’arco has been used in indigenous medicine for generations. One of its compounds, lapachol, has proven effective against various viruses, including influenza, herpes simplex types I and II and poliovirus. It is believed to inhibit replication.

    Studies have shown that glycyrrhizin, a compound found in licorice root was more effective in fighting samples of coronavirus from SARS patients than four antiviral drugs. It reduces viral replication, cell absorption, and the virus’s ability to penetrate cells. It is also being used to treat HIV.

    St. John’s Wort has been proven effective against influenza, herpes simplex, and HIV.

    If you’re prone to viral infections or are dealing with a chronic infection like HIV, as mentioned above, the first step is to get your gut in shape. This is absolutely imperative. The best article to do that with is Best Supplements To Kill Candida and Everything Else You Ever Wanted To Know About Fungal Infections & Gut Health. Everyone who is chronically ill has an abundance of Candida. Yes, everyone.

    Provided your gut is healthy, or if you just feel the need to skip that part, here are the supplements to take in order to make sure your immune system is able to fight off viruses:

    While there are most supplements listed above, the combination of these listed here is more than enough to balance out the body and ward off viral infection.

    In the Kitchen: Prevent the Spread of Infection 

    Bacteria can spread anywhere in the kitchen. So it's important to wash your hands and kitchen surfaces before and after making food. Bacteria can spread from one surface to another without you knowing it. If the bacteria get into food, they can cause foodborne illnesses.

    Sources Of Contamination 

    Hand-to-hand or hand-to-food contact. Most viruses and bacteria that cause colds, flu, and foodborne illnesses are spread this way. People with hepatitis A, noroviruses, or the bacteria staphylococcus and streptococcus can pass these illnesses on to others by handling food. 

    Raw meats, poultry, and fish. These carry many harmful bacteria. One of the most serious is E.coli. This is the organism found mostly in undercooked hamburger. It is one of the most common causes of foodborne illness, according to the CDC. This type of bacteria causes hemolytic uremic syndrome. This is an often-deadly disease that strikes mostly children. Older adults are also at high risk. 

    Chicken, turkey, and poultry. These are linked to shigella, salmonella, and campylobacter. These are bacteria that cause diarrhea, cramping, and fever. Most meat can be contaminated with toxoplasmosis. This is a parasitic disease dangerous to both pregnant women and unborn babies.

    Seafood, particularly oysters, clams, and other shellfish. These can be contaminated with the vibrio species of bacteria that causes diarrhea. Or they can be contaminated with hepatitis A virus.

    Unpasteurized cheese and some meat. These can be contaminated with a strain of bacteria (Listeria monocytogenes) that can cause disease in people. It can also cause miscarriage or damage to a developing baby during pregnancy. Listeria is often found in soft cheeses such as brie. It's found more often in imported cheeses than in U.S. cheeses. Listeria is one of the few bacteria that grow well in the 40°F (4°C) temperature of a refrigerator.

    Contaminated fruits and vegetables. These can carry many organisms and parasites, depending on where they were grown and how they were processed.

    Contaminated Kitchen Gadgets 

    Items in the kitchen can be contaminated by contact with contaminated people, foods, pets, or other environmental sources. 

    The main way that contamination spreads in the kitchen is by our hands. Too often, people don't wash their hands before making food. And people often don't wash their hands between handling possibly contaminated foods such as meat and other foods that are less likely to be contaminated, such as vegetables. This cross-contamination is a main cause of foodborne disease. 

    Kitchen items that often become contaminated include: 

    • Can openers
    • Cutting boards
    • Countertops. Most people use their countertops not only for food prep, but also for possibly contaminated items such as grocery bags, mail, or household objects.
    • Dishrags, towels, sponges, and scrubbers
    • Garbage disposals
    • Sink drains and the J-shaped pipe under the sink (called a P-trap). This holds some water to block sewer gas from seeping back up through the sink.
    • Refrigerators
    • Complex appliances such as food processors, blenders, and eggbeaters

    Cleaning vs. Disinfecting 

    Many people think that if something looks clean, it's safe. A kitchen can look perfectly clean. But it can be contaminated with a lot of organisms that cause diseases. Cleaning and disinfecting are 2 different things. Cleaning removes grease, food residues, and dirt, as well as a large number of bacteria. But cleaning may also spread other bacteria around. Disinfecting kills organisms (bacteria, virus, and parasites). 

    Disinfectants and sanitizers are widely available as liquids, sprays, or wipes. Any of these works well, killing almost all the bacteria and viruses. You can also make your own inexpensive disinfectant. Just add 1 tablespoon liquid chlorine bleach to 1 gallon of water. Store the solution in a spray bottle and make a new solution every 2 to 3 days. 

    You should clean thoroughly before you disinfect. Food or grease buildup won't allow the disinfectant to get through. 

    How you dry your dishes and utensils also plays an important role in kitchen sanitation. From least effective to most effective, drying processes can be ranked: 

    • Drying with a dishtowel (least effective)
    • Drying with a paper towel
    • Air drying
    • Drying in the dishwasher
    • Sterilizing cycle in dishwasher, if available (most effective)

    Cleaning Hands And Disinfecting The Gadgets

    Always wash your hands before eating, before making food, and after cleaning up the food prep area.

    Outside the kitchen, you should wash your hands:

    • After using the bathroom
    • After handling pets or cleaning up after them
    • After caring for another sick person
    • Any time that you think your hands might be contaminated

    To wash your hands, use soap and water. Always clean the palms, the top surfaces, between the fingers, and up the wrists. Short fingernails help maintain cleanliness. 

    According to the CDC, plain soap works the best. Studies have shown that antibacterial soaps and cleaners are possibly linked to antibiotic-resistant infections. And they don't kill germs much better than regular soap. Alcohol-based antibacterial hand sanitizers can come in handy when there is no water for washing. Follow this method for good handwashing: 

    • Use soap and warm running water.
    • Lather your hands well.
    • Wash all surfaces, including between your fingers, the palms and backs of your hands, wrists, and under your fingernails.
    • Wash thoroughly for 20 seconds. (Ask your children to say their ABCs while they wash—that way they'll spend enough time washing.)
    • Rinse well.
    • Make this a habit, especially before meals and after using the bathroom, whether you're sick or not.

    If soap and water are not available, an alcohol-based hand sanitizer that contains at least 60% alcohol can be used to clean your hands. When using these products: 

    • Apply the gel to the palm of one hand.
    • Rub your hands together.
    • Rub the product over all surfaces of your hands and fingers until they are dry.

    Here are some tips to prevent infections from kitchen gadgets: 

    • Can openers, handheld and electric. Clean after each use. After cleaning, wipe with your bleach solution (or commercial disinfectant). Let air dry.
    • Cutting boards. If practical, keep 2 cutting boards. Use 1 for meat and 1 for fruits and vegetables. Clean after each use. The meat cutting board should be sprayed or wiped with your bleach solution and allowed to air dry. Rinse the board in clear water before the next use. This helps remove remaining bleach taste from the board.
    • Countertops. Clean them well. Then spray or wipe with bleach solution. Allow to air dry. If there is a remaining "frost" from the bleach, it may be wiped off with a clean cloth.
    • Dishrags, towels, sponges, and scrubbers. These are often highly contaminated. You shouldn't use a sponge in the kitchen. Use a clean dishcloth daily. After use, rinse thoroughly and air dry. If you use the dishcloth for wiping the floor or wiping up after pets or any general cleaning, put it in the laundry and get a clean one. Scrubbers (metal or plastic) should be washed in the dishwasher each time you run it. If you don't have a dishwasher, rinse them well to remove any visible food residue. Then soak them in your bleach solution for 10 minutes.
    • Garbage disposals. The film that builds up on the inside of the disposal is filled with bacteria. Use a long-handled angled brush and a chlorinated cleansing powder to scrub the inside walls of the disposal and the underside of the rubber splash guard. Let the cleanser to remain in place (don't rinse) until the next time the disposal is used. This gives the chlorinated disinfectant time to kill the bacteria. This should be done at least once a month. Make sure the disposal is off and can't be turned on during this procedure.
    • Sink drains and P-trap. Before going to bed, pour 1 cup of hot water into the drain. Wait a minute for the drain to soak up heat from the water. Then pour in 1 cup of chlorine bleach (undiluted). Let this stand overnight. This should be done every 1 to 2 weeks. This will help sanitize the drain and keep odors down. But it will also help keep the drain running freely.
    • Refrigerators. The fridge should be cleaned thoroughly from time to time. After cleaning, it should be wiped with your bleach solution. Then the food should be put back in. Spills should be cleaned up right away. Don't let food get moldy or decay in the fridge.
    • Complex appliances, such as food processors, blenders, and eggbeaters. The dishwasher is the best way to clean these items. First check the items well and remove any bits of food. Then put the washable parts of these items in the dishwasher. 

    Interferons And Cytokines With Antiviral Activity

    Interferon (IFN) is a protein which is classically designated as inducing an antiviral state in cells. Four cytokines, IL-1beta, TNF-alpha, IL-4 and IL-13 appear to induce an antiviral state in these cells in the 100 to 800 pg/ml range independent of exogenous IFNs. Read more here.

    Inactivation Of Enterovirus By Glutaraldehyde

    Glutaraldehyde has been studied as a disinfectant against a number of bacteria and bacterial spores, but the literature on the effect on viruses seems very limited. Prompted by the need for disinfectants for use where chlorine compounds and formalin seems less desirable, the present study was carried out using an apparently very stable strain of coxsackievirus B3. The effect of glutaraldehyde was studied at different pH values, at different temperatures, in the presence or absence of serum, and using different concentrations. Each of these parameters was followed keeping the others at constant value. Thus a rather intensive practical study was carried out, but no attempt to elucidate the nature of the inactivating process was made. Klein and Deforest (5) studied the inactivation of seven different viruses using, among other substances, bicarbonate-buffered glutaraldehyde. Their description is very brief, but it may be concluded that at room temperature
    and presumably at pH 7.4 all viruses examined were inactivated by 2% glutaraldehyde.

    Glutaraldehyde Inactivation Of Enveloped DNA Viruses In The Preparation Of Haemoglobin-Based Oxygen Carriers

    Glutaraldehyde (GA), used medically as a disinfectant and as a crosslinker for haemoglobin (Hb)-based oxygen carriers (HBOCs), was investigated for its ability to inactivate viruses during the preparation of these artificial blood substitutes. Porcine parvovirus (PPV; a non-enveloped DNA virus) and porcine pseudorabies virus (PRV; an enveloped DNA virus) were used as the virus indicators. Upon treatment with 0.1 mM GA, the titer of PRV decreased from 9.62 log10 to 2.62 log10 within 0.5 h, whereas that of PPV decreased from 7.00 log10 to 2.30 log10 in 5 h. Following treatment with 1.0 mM GA, the titer of PRV decreased from 11.00 log10 to 1.97 log10 within 0.5 h, whereas that of PPV decreased from 7.50 log10 to 3.43 log10 in 4.5 h. During the polymerization of Hb with GA, the GA concentration decreased to 1.0 and 0.1 mM within 30 and 50 min, respectively, at a GA:Hb molar ratio of 10:1, whereas at a GA:Hb molar ratio of 30:1, GA decreased to those same concentrations in 1.5 and 2.5 h, respectively. This rapid decrease in GA concentration during its polymerization with Hb indicates that GA must be added into the Hb solution in a short time in order to get as high a initial concentration as possible. In this study, the GA can only inactivate PRV effectively, given that a longer time (4.5 h) was required for it to inactivate the PPV titer. This study therefore demonstrates that GA inactivates the enveloped DNA virus only during the preparation of HBOCs.

    Can UV Light Fight the Spread of Influenza?

    Scientists have known for decades that broad-spectrum germicidal UV light, which has wavelengths between 200 and 400 nanometers (nm), is highly effective at killing bacteria and viruses by destroying the molecular bonds that hold their DNA together. Read more here.

    Sulfated Polysaccharide, Curdlan Sulfate, Efficiently Prevents Entry/Fusion and Restricts Antibody-Dependent Enhancement of Dengue Virus Infection In Vitro: A Possible Candidate for Clinical Application

    Curdlan sulfate (CRDS), a sulfated 1→3-β-D glucan, previously shown to be a potent HIV entry inhibitor, is characterized in this study as a potent inhibitor of the Dengue virus (DENV). CRDS was identified by in silico blind docking studies to exhibit binding potential to the envelope (E) protein of the DENV. CRDS was shown to inhibit the DENV replication very efficiently in different cells in vitro. Minimal effective concentration of CRDS was as low as 0.1 µg/mL in LLC-MK2 cells, and toxicity was observed only at concentrations over 10 mg/mL. CRDS can also inhibit DENV-1, 3, and 4 efficiently. CRDS did not inhibit the replication of DENV subgenomic replicon. Time of addition experiments demonstrated that the compound not only inhibited viral infection at the host cell binding step, but also at an early post-attachment step of entry (membrane fusion). The direct binding of CRDS to DENV was suggested by an evident reduction in the viral titers after interaction of the virus with CRDS following an ultrafiltration device separation, as well as after virus adsorption to an alkyl CRDS-coated membrane filter. The electron microscopic features also showed that CRDS interacted directly with the viral envelope, and caused changes to the viral surface. CRDS also potently inhibited DENV infection in DC-SIGN expressing cells as well as the antibody-dependent enhancement of DENV-2 infection. Based on these data, a probable binding model of CRDS to DENV E protein was constructed by a flexible receptor and ligand docking study. The binding site of CRDS was predicted to be at the interface between domains II and III of E protein dimer, which is unique to this compound, and is apparently different from the β-OG binding site. Since CRDS has already been tested in humans without serious side effects, its clinical application can be considered.

    Chlorine Dioxide And Sodium Hypochlorite Produces Potent Antiviral Activity

    We evaluated the antiviral activity of a chlorine dioxide gas solution (CD) and sodium hypochlorite (SH) against feline calicivirus, human influenza virus, measles virus, canine distemper virus, human herpesvirus, human adenovirus, canine adenovirus and canine parvovirus. CD at concentrations ranging from 1 to 100 ppm produced potent antiviral activity, inactivating >or= 99.9% of the viruses with a 15 sec treatment for sensitization. The antiviral activity of CD was approximately 10 times higher than that of SH. Read more here.

    In Vitro Virucidal Effects Of Allium Sativum (Garlic) Extract And Compounds

    Garlic (Allium sativum) has been shown to have antiviral activity, but the compounds responsible have not been identified. Using direct pre-infection incubation assays, we determined the in vitro virucidal effects of fresh garlic extract, its polar fraction, and the following garlic associated compounds: diallyl thiosulfinate (allicin), allyl methyl thiosulfinate, methyl allyl thiosulfinate, ajoene, alliin, deoxyalliin, diallyl disulfide, and diallyl trisulfide. Activity was determined against selected viruses including, herpes simplex virus type 1, herpes simplex virus type 2, parainfluenza virus type 3, vaccinia virus, vesicular stomatitis virus, and human rhinovirus type 2. The order for virucidal activity generally was: ajoene > allicin > allyl methyl thiosulfinate > methyl allyl thiosulfinate. Ajoene was found in oil-macerates of garlic but not in fresh garlic extracts. No activity was found for the garlic polar fraction, alliin, deoxyalliin, diallyl disulfide, or diallyl trisulfide. Fresh garlic extract, in which thiosulfinates appeared to be the active components, was virucidal to each virus tested. The predominant thiosulfinate in fresh garlic extract was allicin. Lack of reduction in yields of infectious virus indicated undetectable levels of intracellular antiviral activity for either allicin or fresh garlic extract. Furthermore, concentrations that were virucidal were also toxic to HeLa and Vero cells. Virucidal assay results were not influenced by cytotoxicity since the compounds were diluted below toxic levels prior to assaying for infectious virus. These results indicate that virucidal activity and cytotoxicity may have depended upon the viral envelope and cell membrane, respectively. However, activity against non-enveloped virus may have been due to inhibition of viral adsorption or penetration.

    Virus Inactivation Mechanisms: Impact of Disinfectants On Virus Function And Structural Integrity

    Oxidative processes are often harnessed as tools for pathogen disinfection. Although the pathways responsible for bacterial inactivation with various biocides are fairly well understood, virus inactivation mechanisms are often contradictory or equivocal. In this study, we provide a quantitative analysis of the total damage incurred by a model virus (bacteriophage MS2) upon inactivation induced by five common virucidal agents (heat, UV, hypochlorous acid, singlet oxygen, and chlorine dioxide). Each treatment targets one or more virus functions to achieve inactivation: UV, singlet oxygen, and hypochlorous acid treatments generally render the genome nonreplicable, whereas chlorine dioxide and heat inhibit host-cell recognition/binding. Using a combination of quantitative analytical tools, we identified unique patterns of molecular level modifications in the virus proteins or genome that lead to the inhibition of these functions and eventually inactivation. UV and chlorine treatments, for example, cause site-specific capsid protein backbone cleavage that inhibits viral genome injection into the host cell. Combined, these results will aid in developing better methods for combating waterborne and foodborne viral pathogens and further our understanding of the adaptive changes viruses undergo in response to natural and anthropogenic stressors.

    Supporting Information 

    A description of the reagents and organisms used; protocols for the disinfection by FC and ClO2; the production of [15N] metabolically labeled MS; and qRT-PCR protocols; tables containing degradation rate constants for viral infectivity and functions; degradation rate constants for individual genome segments, CP peptides and AP peptides; description of protein regions covered by MALDI; primer sequences and genome segments for qRT-PCR analysis; CP and AP peptides detected by MALDI; illustration of the decay of virus infectivity, binding function, injection function, and replication function with UV treatment; illustration of the disinfection kinetics by all five treatments; MALDI spectra showing CP cleavage upon disinfection by FC; example of calibration curve used to track C/C0 for CP and AP peptides; example of the first-oder decay of a peptide. This material is available free of charge via the Internet at

    Evaluation Of Hypochlorite-Releasing Disinfectants Against The Human Immunodeficiency Virus (HIV)

    Using a quantitative suspension test method, the antiviral activity of sodium hypochlorite (NaOCl) and sodium dichloroisocyanurate (NaDCC) against human immunodeficiency virus (HIV) was investigated. Viral suspensions were prepared containing 104–105 syncitial forming units ml−1 in 0·9% saline or 0·9% saline containing 10% Math Eq plasma to simulate clean and dirty conditions. A syncitial inhibition assay on C8166 lymphoblastoid line was used to determine viral titre. Results indicate that satisfactory disinfection (3–4 log reduction in 2 min) can be achieved using NaDCC and NaOCl at concentrations of 50 ppm and 2500 ppm available chlorine (AvCl2) for clean and soiled conditions respectively. For treatment of blood spillages, the addition of NaDCC and NaOCl solutions (10 000 ppm) to equal volumes of contaminated blood (giving a final AvCl2 concentration of 5000 ppm of blood) was sufficient to produce total kill within 2 min. For treatment of spillage material, chlorine-releasing powder formulations—which produce higher AVCl2 concentrations and achieve containment of spillage material—offer an effective alternative.

    Effect Of Formaldehyde Inactivation On Poliovirus

    We show that inactivation with formaldehyde has an effect on early steps of viral replication as it reduces the ability of PV to bind to hPVR, decreases the sensitivity of PV to convert to 135S particles, and abolishes the infectivity of its viral RNA. Read more here.

    Evaluation Of Inactivation Methods For Severe Acute Respiratory Syndrome Coronavirus In Noncellular Blood Products

    Severe acute respiratory syndrome coronavirus (SARS-CoV) has been detected in the blood of infected individuals, which may have the potential to contaminate donated blood and plasma-derived products in the event of a future outbreak. Effective methods for inactivating the SARS-CoV in protein solutions are described in this report.

    Study Design And Methods:
    Heat, ultraviolet (UV) irradiation, octanoic acid, and solvent/detergent (S/D) methods were tested individually for their ability to inactivate SARS-CoV in protein solutions appropriately mimicking blood-derived products. Treated samples were tested for inactivation in a tissue culture growth assay.

    Viral inactivation by heat treatment at 60 degrees C required 15 to 30 minutes to inactivate the SARS-CoV. UVC efficiently inactivated SARS-CoV in 40 minutes, whereas UVA required the addition of psoralen to enhance inactivation of the virus. The presence of bovine serum albumin limited the ability of UVC and UVA to inactivate SARS-CoV and octanoic acid treatment does not reduce the infectivity of SARS-CoV-spiked protein solutions. S/D treatment required 2, 4, and up to 24 hours for Triton X-100, Tween 80, and sodium cholate inactivation, respectively.

    Heat, UVC irradiation, and S/D treatments effectively inactivate SARS-CoV, whereas octanoic acid treatment is insufficient for inactivation of the virus. Read more here.

    Photodynamic Inactivation Of Viruses

    Photodynamic inactivation (PDI) has been used to inactivate microorganisms through the use of photosensitizers. The inactivation of mammalian viruses and bacteriophages by photosensitization has been applied with success since the first decades of the last century. Due to the fact that mammalian viruses are known to pose a threat to public health and that bacteriophages are frequently used as models of mammalian viruses, it is important to know and understand the mechanisms and photodynamic procedures involved in their photoinactivation. The aim of this review is to (i) summarize the main approaches developed until now for the photodynamic inactivation of bacteriophages and mammalian viruses and, (ii) discuss and compare the present state of the art of mammalian viruses PDI with phage photoinactivation, with special focus on the most relevant mechanisms, molecular targets and factors affecting the viral inactivation process. Read more here.

    Propylene Glycol Kills Viruses 

    Propylene Glycol (90% aqueous solution) inactivates (kills) the influenza virus within 3 minutes. It has been found that propylene glycol vapor dispersed into the air of an enclosed space produces a marked and rapid bactericidal effect on microorganisms introduced into such an atmosphere in droplet form. Concentrations of 1 gm. of propylene glycol vapor in two to four million cc. of air produced immediate and complete sterilization of air into which pneumococci, streptococci, staphylococci, H. influenzae, and other microorganisms as well as influenza virus had been sprayed.

    Does Propylene Glycol Kill Bacteria?

    The test concluded that air containing propylene glycol kills off bacteria of all kinds, including disease-causing ones and that PG vapour is invisible, odourless, and non-irritating. It added that PG is essentially non-toxic. Read more here.

    Formalin Virus Inactivation

    Formalin is the chemical most commonly used for inactivation to manufacture viral vaccines such as hepatitis A virus, polio, influenza virus, rabies virus, and simian immunodeficiency virus. Read more here.

    Do Natural Killer Cells Kill Viruses?

    NK cells are activated in response to interferons or macrophage-derived cytokines. They serve to contain viral infections while the adaptive immune response generates antigen-specific cytotoxic T cells that can clear the infection. NK cells work to control viral infections by secreting IFNγ and TNFα. Read more here.

    How Infection Works

    There is a close connection between microbes and humans. Experts believe about half of all human DNA originated from viruses that infected and embedded their nucleic acid in our ancestors’ egg and sperm cells.

    Microbes occupy all of our body surfaces, including the skin, gut, and mucous membranes. In fact, our bodies contain at least 10 times more bacterial cells than human ones, blurring the line between where microbes end and humans begin. Microbes in the human gastrointestinal tract alone comprise at least 10 trillion organisms, representing more than 1,000 species, which are thought to prevent the gut from being colonized by disease-causing organisms. Among their other beneficial roles, microbes synthesize vitamins, break down food into absorbable nutrients, and stimulate our immune systems.

    The vast majority of microbes establish themselves as persistent “colonists,” thriving in complex communities within and on our bodies. In many cases, the microbes derive benefits without harming us; in other cases, both host and microbe benefit.

    And though some microbes make us sick and even kill us, in the long run they have a shared interest in our survival. For these tiny invaders, a dead host is a dead end.

    The success of microorganisms is due to their remarkable adaptability. Through natural selection, organisms that are genetically better suited to their surroundings have more offspring and transmit their desirable traits to future generations. This process operates far more efficiently in the microbial world than in people. Humans produce a new generation every 20 years or so; bacteria do it every 20 to 30 minutes, and viruses even faster. Because they reproduce so quickly, microorganisms can assemble in enormous numbers with great variety in their communities. If their environment suddenly changes, the community’s genetic variations make it more likely that some will survive. This gives microbes a huge advantage over humans when it comes to adapting for survival.

    Types of Microbes
    There are five major categories of infectious agents: Viruses, bacteria, fungi, protozoa, and helminths.

    Viruses are tiny, ranging in size from about 20 to 400 nanometers in diameter (see page 9). Billions can fit on the head of a pin. Some are rod shaped; others are round and 20 sided; and yet others have fanciful forms, with multisided “heads” and cylindrical “tails.”

    Viruses are simply packets of nucleic acid, either DNA or RNA, surrounded by a protein shell and sometimes fatty materials called lipids. Outside a living cell, a virus is a dormant particle, lacking the raw materials for reproduction. Only when it enters a host cell does it go into action, hijacking the cell’s metabolic machinery to produce copies of itself that may burst out of infected cells or simply bud off a cell membrane. This lack of self-sufficiency means that viruses cannot be cultured in artificial media for scientific research or vaccine development; they can be grown only in living cells, fertilized eggs, tissue cultures, or bacteria.

    Viruses are responsible for a wide range of diseases, including the common cold, measles, chicken pox, genital herpes, and influenza. Many of the emerging infectious diseases, such as AIDS and SARS, are caused by viruses.

    Bacteria are 10 to 100 times larger than viruses and are more self-sufficient. These single-celled organisms, generally visible under a low-powered microscope, come in three shapes: spherical (coccus), rodlike (bacillus), and curved (vibrio, spirillum, or spirochete).

    Most bacteria carry a single circular molecule of DNA, which encodes (or programs) the essential genes for reproduction and other cellular functions. Sometimes they carry accessory small rings of DNA, known as plasmids, that encode for specialized functions like antibiotic resistance. Unlike more complex forms of life, bacteria carry only one set of chromosomes instead of two. They reproduce by dividing into two cells, a process called binary fission. Their offspring are identical, essentially clones with the exact same genetic material. When mistakes are made during replication and a mutation occurs, it creates variety within the population that could—under the right circumstances—lead to an enhanced ability to adapt to a changing environment. Bacteria can also acquire new genetic material from other bacteria, viruses, plants, and even yeasts. This ability means they can evolve suddenly and rapidly instead of slowly adapting.

    Bacteria are ancient organisms. Evidence for them exists in the fossil record from more than 3 billion years ago. They have evolved many different behaviors over a wide range of habitats, learning to adhere to cells, make paralyzing poisons and other toxins, evade or suppress our bodies’ defenses, and resist drugs and the immune system’s antibodies. Bacterial infections are associated with diseases such as strep throat, tuberculosis, staph skin infections, and urinary tract and bloodstream infections.

    Other Infectious Agents
    The other three major types of infectious agents include fungi (spore-forming organisms that range from bread mold to ringworm to deadly histoplasmosis), protozoa (such as the agents behind malaria and dysentery), and helminths (parasitic worms like those that cause trichinosis, hookworm, and schistosomiasis).

    A newly recognized class of infectious agents—the prions, or proteinaceous infectious particles—consist only of protein. Prions are thought to cause variant Creutzfeldt-Jakob disease in humans and “mad cow disease” in cattle. These proteins are abnormally folded and, when they come in contact with similar normal proteins, turn them into prions like themselves, setting off a chain reaction that eventually riddles the brain with holes. Prions evoke no immune response and resist heat, ultraviolet light, radiation, and sterilization, making them difficult to control.

    Encountering Microbes
    Microbes have inhabited the earth for billions of years and may be the earliest life forms on the planet. They live in every conceivable ecological niche—soil, water, air, plants, rocks, and animals. They even live in extreme environments, such as hot springs, deep ocean thermal vents, and Antarctic ice. Indeed microbes, by sheer mass, are the earth’s most abundant life form and are highly adaptable to external forces.

    New Meeting Places
    Any changes that create new intersections between microbes and people pave the way for disease-causing agents to enter our species. One such change that has put us at risk is the global human population explosion—from about 1.6 billion people in 1900 to nearly 7 billion today. Humans have cleared forests for agriculture and suburbanization, leading to closer contact with environments that may harbor novel (or newly introduced) pathogens. Through much of the world’s developing tropical regions, the massive expansion of roads and human settlements has also created transition zones filled with opportunities for contact with potential disease-causing agents.

    Human travel and commerce have brought other risks. Almost 2 million passengers, each a potential carrier of infection, travel daily by aircraft to international destinations. International commerce, especially in foodstuffs, adds to the global traffic of disease-causing microbes. Because the transit times of people and goods are often shorter than the incubation periods of infection, carriers of disease can arrive at their destination before the infection they harbor is detectable. International trade and travel are associated with the emergence of such infectious agents as the SARS coronavirus and West Nile virus.

    Entering the Human Host
    Microorganisms capable of causing disease—pathogens—usually enter our bodies through the mouth, eyes, nose, or urogenital openings, or through wounds or bites that breach the skin barrier. Organisms can spread—or be transmitted—by several routes.

    Contact: Some diseases spread via direct contact with infected skin, mucous membranes, or body fluids. Diseases transmitted this way include cold sores (herpes simplex virus type 1) and sexually transmitted diseases such as AIDS. Pathogens can also be spread by indirect contact when an infected person touches a surface such as a doorknob, countertop, or faucet handle, leaving behind microbes that are then transferred to another person who touches that surface and then touches his or her eye, mouth, or nose. Droplets spread by sneezes, coughs, or simply talking can transmit disease if they come in contact with mucous membranes of the eye, mouth, or nose of another person. SARS, tuberculosis, and influenza are examples of diseases spread by airborne droplet transmission.

    Common vehicles: Contaminated food, water, blood, or other vehicles may spread pathogens. Microorganisms like E. coli and Salmonella enter the digestive system in this manner.

    Vectors: Creatures such as fleas, mites, ticks, rats, snails, and dogs—called vectors—can also transmit disease. The most common vector for human infection is the mosquito, which transmits malaria, West Nile virus, and yellow fever.

    Airborne transmission: Pathogens can also spread when residue from evaporated droplets or dust particles containing microorganisms are suspended in air for long periods of time. Diseases spread by airborne transmission include measles and hantavirus pulmonary syndrome.

    How Pathogens Make Us Sick
    Infection does not necessarily lead to disease. Infection occurs when viruses, bacteria, or other microbes enter your body and begin to multiply. Disease, which typically happens in a small proportion of infected people, occurs when the cells in your body are damaged as a result of infection, and signs and symptoms of an illness appear.

    In response to infection, your immune system springs into action. White blood cells, antibodies, and other mechanisms go to work to rid your body of the foreign invader. Indeed, many of the symptoms that make a person suffer during an infection—fever, malaise, headache, rash—result from the activities of the immune system trying to eliminate the infection from the body.

    Pathogenic microbes challenge the immune system in many ways. Viruses make us sick by killing cells or disrupting cell function. Our bodies often respond with fever (heat inactivates many viruses), the secretion of a chemical called interferon (which blocks viruses from reproducing), or by marshaling the immune system’s antibodies and other cells to target the invader. Many bacteria make us sick the same way, but they also have other strategies at their disposal. Sometimes bacteria multiply so rapidly they crowd out host tissues and disrupt normal function. Sometimes they kill cells and tissues outright. Sometimes they make toxins that can paralyze, destroy cells’ metabolic machinery, or precipitate a massive immune reaction that is itself toxic.

    Other classes of microbes attack the body in different ways:

    • Trichinella spiralis, the helminth that causes trichinosis, enters the body encased in cysts residing in undercooked meat. Pepsin and hydrochloric acid in our bodies help free the larvae in the cysts to enter the small intestine, where they molt, mature, and ultimately produce more larvae that pass through the intestine and into the bloodstream. At that point they are free to reach various organs. Those that reach skeletal muscle cells can survive and form new cysts, thus completing their life cycle.
    • Histoplasma capsulatum, a fungus that transmits histoplasmosis, grows in soil contaminated with bird or bat droppings. Spores of the fungus emerge from disturbed soil and, once inhaled into the lungs, germinate and transform into budding yeast cells. In its acute phase, the disease causes coughing and flu-like symptoms. Sometimes histoplasmosis affects multiple organ systems and can be fatal unless treated.
    • The protozoa that cause malaria, which are members of the genus Plasmodium, have complex life cycles. Sporozoites, a cell type that infects new hosts, develop in the salivary glands of Anopheles mosquitos. They leave the mosquito during a blood meal, enter the host’s liver, and multiply. Cells infected with sporozoites eventually burst, releasing another cell form, merozoites, into the bloodstream. These cells infect red blood cells and then rapidly reproduce, destroying the red blood cell hosts and releasing many new merozoites to do further damage. Most merozoites continue to reproduce in this way, but some differentiate into sexual forms (gametocytes) that are taken up by the female mosquito, thus completing the protozoan life cycle.

    These and many other ingenious pathways to causing disease demonstrate pathogens’ rich evolutionary legacy and their continued inventiveness. In the next section, we look more closely at how some of these organisms have learned to thrive—often at humans’ expense. Read more here.

    Does Copper Kill Germs?
    Ashley Laderer | March 25, 2020 |

    Yes, it's effective against COVID-19 within 4 hours. While you may think that antiseptic wipes or sprays are necessary to kill germs, there's actually a metal that kills germs on contact — no cleaning supplies necessary.

    Believe it or not, the use of copper for health purposes dates all the way back to Ancient Egypt, and scientists today are still learning about the amazing benefits of copper. Here's what you need to know.

    Copper Does Kill Germs
    Copper has antimicrobial properties, meaning it can kill microorganisms like bacteria and viruses. However, the microorganism has to come in contact with the copper in order for it to be killed. This is referred to as "contact killing."

    According to Edward Bilsky, Ph.D., Provost and Chief Academic Officer at Pacific Northwest University of Health Sciences, copper can kill germs in a few ways:

    • It disrupts bacterial cell membranes — copper ions damage cell membranes or "envelopes" and can destroy the DNA or RNA of the microbe
    • It generates oxidative stress on bacterial cells and creates hydrogen peroxide that can kill the cell
    • It interferes with proteins that operate important functions that keep bacterial cells alive

    The exact mechanism of how copper interferes with proteins in bacterial cells is not fully understood yet, but the current hypothesis is mis-metalation, thanks to the fact that copper is a stable metal.

    "Mis-metalation is the ability of a metal to basically replace another metal," says Michael D. L. Johnson, Ph.D., Assistant Professor of Immunobiology at the University of Arizona College of Medicine in Tucson. "Copper can just replace some of the other metals that are present in some of these other proteins [in bacteria] and by doing so, it blocks the function of those proteins."

    When you block a protein's function, it starts a bacteria-killing chain reaction. "By blocking the function of the protein, you block the function of the pathway. When you block the function of the pathway, you block the function of the organism, and then the organism is just dead in the water," says Johnson.

    Copper Can Kill Viruses And Bacteria
    Studies have shown that copper can kill many types of germs on contact. According to a 2015 study published in Health Environments Research and Design Journal, some of the common germs copper has been proven to kill are:

    • MRSA
    • E. coli
    • Influenza A
    • Norovirus

    Brand new research published in the New England Journal of Medicine found that copper can be effective against SARS-CoV-2, the virus responsible for the coronavirus pandemic. The study showed that after four hours, the virus was no longer infectious on copper's surface. In comparison, coronavirus was still infectious on plastic surfaces after 72 hours.

    The Applications Of Antimicrobial Copper
    One of the main applications of copper is in hospitals, although the use is not widespread. In the same study as above, researchers determined the germiest surfaces in a hospital room – bed rails, call buttons, chair arms, tray table, data input, and IV pole – and replaced them with copper components.

    The results were very promising. Compared to the rooms made with traditional materials, there was an 83% reduction in bacterial load on the surfaces in the rooms with copper components. Additionally, infection rates of patients were reduced by 58%.

    Technically, you can use copper at home. However, according to Johnson, the majority of copper products for the home have a treatment on it to prevent the oxidation that causes the beautiful original color of the copper to turn to a greenish-blue over time. This treatment prevents you from getting the beneficial antimicrobial properties of copper. That being said, copper still has the ability to be toxic to bacteria when it's at this oxidized greenish state, however, according to Johnson, scientists still don't know exactly how this mechanism works.

    According to current research, the downside of using copper is that it isn't as effective at destroying viruses as it is at killing bacteria – particularly if it's an airborne virus. Much of this has to do with the fact that viruses are technically not living organisms — they are infection agents, which are not "alive" like cells are, and as such they are more durable.

    "Viruses are different in that they are not cells but rather infect healthy cells that allows them to replicate. The virus can come in direct contact with the upper respiratory tract and eyes and enter healthy cells, so a copper strategy would be largely ineffective [in that case]," says Bilsky.

    Another downside is that there are some unsubstantiated claims that may mislead people. Some companies try to market copper jewelry or copper-infused socks as antimicrobial protection for the wearer, but these are ineffective.

    Hopefully, more research will continue to be conducted so we can better understand the antimicrobial properties of copper and the most effective ways to use it in everyday life to keep us healthy.

    How To Use Alcohol (Ethanol) To Kill Viruses

    Efficacy Of Ethanol Against Viruses In Hand Disinfection

    Ethanol is used worldwide in healthcare facilities for hand rubbing. It has been reported to have a stronger and broader virucidal activity compared with propanols. The aim of this review was to describe the spectrum of virucidal activity of ethanol in solution or as commercially available products. A systematic search was conducted. Studies were selected when they contained original data on reduction of viral infectivity from suspension tests (49 studies) and contaminated hands (17 studies). Ethanol at 80% was highly effective against all 21 tested, enveloped viruses within 30 s. Murine norovirus and adenovirus type 5 are usually inactivated by ethanol between 70% and 90% in 30 s whereas poliovirus type 1 was often found to be too resistant except for ethanol at 95% (all test viruses of EN 14476). Ethanol at 80% is unlikely to be sufficiently effective against poliovirus, calicivirus (FCV), polyomavirus, hepatitis A virus (HAV) and foot-and-mouth disease virus (FMDV). The spectrum of virucidal activity of ethanol at 95%, however, covers the majority of clinically relevant viruses. Additional acids can substantially improve the virucidal activity of ethanol at lower concentrations against, e.g. poliovirus, FCV, polyomavirus and FMDV although selected viruses such as HAV may still be too resistant. The selection of a suitable virucidal hand rub should be based on the viruses most prevalent in a unit and on the user acceptability of the product under frequent-use conditions.

    Virucidal Agents

    Virucidal agents are chemical substances that attack and inactivate viral particles outside the cell (virions). In general this is accomplished by damaging their protein shells (capsid) or the substance penetrates the core itself, where it destroys the genetic material. Damage to the virion structure is also possible.

    These agents are used not only for traditional surface disinfection or sterilization of blood, blood products, and other medicinal products as well as in antiviral chemotherapy. They have also been used in recent times for inactivation of viruses in foodstuffs, detergents or cosmetics. Below is given an overview of the data currently available on the performance of these substances when used for the latter applications (cleaning and cosmetics). These include:

    • hydrogen peroxide, hypochlorites, cupric and ferric ions, per-acids
    • ethanol, parachlorometaxylenol in a sodium C14-16 olefin sulfonate, glutaraldehyde, quaternary ammonium salts, chlorhexidine and chlorhexidine gluconate, curdline sulphate, glycerol, lipids, azodicarbonamide, cicloxolone sodium, dichlorisocyanuric acid (sodium salt), benzalkonium salts, disulfate benzamides and benzisothiazolones, congo red, ascorbic acid, nonoxynol-9, para-aminobenzoic acid, bis(monosuccinamide) derivative of p,p’-bis(2-aminoethyl) diphenlyi-C60) (fullerene).
    • merocyanine, benzoporphyrin derivative monoacid ring A, rose bengal, hypericin, hypocrellin A, anthraquinones extracted from plants, sulfonated anthraquinones and other anthraquinone derivatives 
    • gramicidine, gossypol, garlic (Allium sativum) extract and its components: ajoene, diallyl thiosulfinate (allicin), allyl methyl thioulfinate, methyl allyl thiosulfinate, extracts of ledium, motherworth, celandine, black currant, coaberry and bilberry, extract of Cordia salicifolia, steam distillate from Houttuynia cordata (Saururaceae) and its component, 5,6,7-trimethoxyflavone from Calicarpa japonica, isoscullarein (5,7,8,4’-tetrahydroxyflavone) from Scutellaria baikalensis and isoscutellarein-8-methylether, alkaloids and phytosteryl ester compounds.

    Virucidal agents represent chemical substances (individual compounds or compositions) attacking and inactivating (decreasing the infectivity of) the extracellular viral particles (virions). Principally, virucidals damage the virion protein capsid or supercapsidal membrane, or penetrating into the virion destroy the viral genome. The viral particle integrity could also be affected.

    Four major application fields of the virucidal agents could be distinguished, namely:

    • Disinfection of the environment - historically this is the oldest and still widely developing field.
    • Sterilization of biological products for parenteral administration: blood, blood products, medicinals.
    • Antiviral chemotherapy - some antiviral agents could exert virucidal mode of action as a specific or secondary effect.
    • Elimination of viruses from food, sanitary products and cosmetics. This is the newest and most prospective field of application.

    The following literary update involves substances manifesting distinct virucidal properties making them potentially suitable to be used in sanitation and cosmetics. Some of them have been already registered as disinfectants or blood products sterilyzing agents.

    Use Inorganic Compounds To Kill Viruses

    Hydrogen peroxide (known as a disinfectant) in solution (3%-6%) showed a very low virucidal effect towards enteroviral virions (1 min treatment in the surface test vs. poliovirus 1 dried suspension) or lack of effect (1 min in the suspension test) [1].

    High concentrations (9200 ppm avCl2) were effective (a >4 lg reduction) against a dried enterovirus (poliovirus 1) suspension (in the surface test) in 1 min. Lower hypochlorite concentrations (1000 ppm avCl2) were less effective .

    Cupric And Ferric Ions
    These metal ions were able to inactivate a comparatively wide spectrum of enveloped or nonenveloped, ss- or ds RNA or DNA viruses, e.g. Junin (arenavirus), herpes simplex viruses 1 and 2, and different phages (X174, T7, 6). The virucidal effect of these metals was enhanced by the addition of peroxide, particularly for copper (II). The combinations mentioned above should be able to inactivate most, if not all, viruses that have been found contaminating medical devices .

    Per-acid based disinfectants are known as powerful virucides. Some commercial preparatives (e.g. “Peral-S” disinfectant) revealed a strong virucidal activity on enterovirus (Coxsackie B6 virus) and herpesvirus (herpes simplex virus 1) at 0.1% concentration within 30 seconds only. The so-called “floating technique” was applied in this study .

    Organic compounds

    At 70% this compound showed variable results in a virucidal testing (surface test) vs. the enterovirus polio 1, while in the suspension test was ineffective in 1 min.

    Parachlorometaxylenol in a sodium C14-16 olefin sulfonate
    At 0.5% this composition proposed as soap (for a health care personnel hand wash) demonstrated a strong virucidal effect against HIV1 in the presence of 50% whole human blood within 30-60 sec. More than 99.9% of the virus was inactivated at 1:5 - 1:30 dilutions.

    At 2% this compound was effective in the surface test on poliovirus 1 (> 4 lg reduction) for 1 min. A 2% alkaline glutaraldehyde was efficient as a virucidal and bactericidal agent against a mixture of some picornaviruses (hepatitis A and poliovirus 1) and some bacteria (Pseudomonas aeruginosa, Mycobacterium bovis and Mycobacterium gordonae) in the so called carrier test (with a contact time 10 min at 20oC). The criterion of efficacy was a minimum of 3-log reduction in the infectivity titers of the oreganisms tested. In this case the use of the compound was endoscopes disinfection via baths.

    Quaternary Ammonium Salts
    A newer generation of quaternary ammonium compounds showed a distinct virucidal effect against calici-, parvo- and herpesviruses (causative agents of diseases in domestic cats and dogs) for à 10-min contact at room temperature.

    Chlorhexidine And Chlorhexidine Gluconate
    Chlorhexidine could be considered as efficient vaginal virucidals preventing heterosexual transmission of HIV. The gluconate derivative at 0.12% concentration (proposed for a mouthrinse preparative) was effective on a unusually wide spectrum of viruses: influenza A, parainfluenza, HSV, CMV and HBV. The poliovirus was unsensitive. The contact time was 30 sec. The probable mode of action is an interaction with the virion envelope, and the deferences in the virucidal effects are based on differences in the physical/chemical structures of the virus envelopes.

    Curdline Sulfate
    This newly synthesized sulfated polysaccharide preventing the binding of HIV to the surface of H9 cells exhibited a weak virucidal activity.

    This substance known as a viral preservation medium in tissue samples at a 50% concentration for a short period of time, applied at higher concentrations showed a strong virucidal activity at different temperatures (4, 20 and 37oC) against HIV, HSV1 and polioviruses. Both a dehydrating action and an influence on the enzymatic processes of nucleic acid breakdown are discussed as the possible base of the glycerol action. Otherwise, glycerol is known to dehydrate the skin, the extracted water being replaced by glycerol, preserving the original structure .

    Purified lipids can inactivate enveloped viruses, bacteria, fungi, and protozoa. This activity is atributed to certain monoglycerides and fatty acids that are released from triglycerides by lipolytic activity. Medium chain length antiviral lipids can be added to human blood products that contain HIV-1 and HIV-2 and redice the cell-free virus concentration by as much as 11 lg TCID50/ml. Antimicrobial lipids can disrupt cell membranes and subsequently lyse leukocytes which potentially carry virus. Preliminary studies indicate that lipids decrease sperm motility and viability suggesting that lipids may potentially be used as combination spermicidal and virucidal agents.

    This compound is a nucluocapsid inhibitor efficient against HIV-1 and other retroviruses, and its virucidal effect is based on the prevention of reverse transcription initiation and a block of infectious virion formation from cells.

    Cicloxolone Sodium
    This compound manifested a wide-spectrum virucidal effect: towards HSV-1, HSV-2, VSV, adenoviruses (type 5). A relocation of assembled virus is presumed. Besides, a very well pronounced inhibitory effect on the replication of different virus families (picorna-, reo-, toga-, bunya- and adenoviruses) was established.

    Dichlorisocyanuric Acid (Sodium Salt)
    The compound revealed a marked virucidal activity against ectromelia virus (poxvirus family). It is proposed for use as a water disinfectant.

    Benzalkonium Salts
    This group of positively charged surface active alkylamine biocides interacts with guanine nucleotide triphosphate-binding proteins. Benzalkonium salts have antiproliferative effects on a variety of cells, affect cytokine gene expression, and are also effective virucidal, bactericidal and fungicidal agents. Virucidal actiivity was found against HIV, papillomaviruses and herpesviruses.

    Disulfate Benzamides And Benzisothiazolones
    A group of 4 derivatives possesses anti-HIV virucidal activity based on an ejection of zinc from the virus nucleocapside protein.

    Congo Red
    This membrane-binding dye inactivates HIV in the presence of magnesium dichloride (Mg++ ions) only. This effect was found to be revesible as validated by washing of the cells by Hanks’ solution + MgCl2 following capture of the virions from cell-free HIV-Congo red inactivation mixture.

    Ascorbic Acid
    Vitamine C demonstrated a virucidal effect on HIV in the presence of Mg++ ions. Its virucidal properties are closed to those of Congo red.

    This a virucidal and spermicidal agent used for vaginal treatment preventing heteroxual transmission of HIV or for impregnation of surgical gloves serving as a barrier for HIV infection.

    Para-Aminobenzoic Acid
    This compound showed a marked anti-herpesvirus (HSV-1) activity both in vitro and in vivo, and virucidal mode of action was presumed.

    Bis(monosuccinamide) derivative of p,p’-bis(2-aminoethyl) diphenyl-C60 (Fullerene) 
    This substance showed activity against HIV-1 and HIV-2. Its virucidal properties were confirmed by the contact (virus-inactivating) test. In cell-free system fullerene manifested comparable activity against HIV-1 reverse transcriptase and DNA polymerase (alpha), and a selective activity towards HIV-1 protease.

    Photosensitizing Virucidal Agents 

    This pyrimidinone derivative, a lipophilic dye, is a photosensitizing virucidal agent efficient vs. lipid-containing, enveloped, viruses, e.g. HSV. Its activity was proved initially on bacteriophages as surrogate for animal viruses.

    Benzoporphyrin Derivative Monoacid Ring A
    This compound destroyed enveloped viruses (HIV) in blood and blood products when activated by light. Its eliminates the virus but did not damage blood cells or blood components.

    Rose Bengal
    Virucidal spectrum of this compound envolves various groups of enveloped viruses: orthomyxo- (influenza A), paramyxo (Sendai), rhabdo- (VSV) and retroviruses (HIV, Friend leukemia virus). HIV and VSV were photodynamically inactivated by this dye at nanomolar concentrations. The non-enveloped viruses are unsusceptible. The compound inactivated influenza virus upon exposure to light. It was established that the virucidal activity of photodynamic agents against enveloped viruses may be generally due to inactivation of their fusion protein(s).

    Concentrations required for inactivation were found to depend upon the ratio of rose bengal to virus, rather than on nominal aqueous concentration. The HA2 portion of influenza fusion protein HA underwent two different apparently mutually exclusive modifications upon illumination with rose bengal. Inactivation of the viral fusion was inhibited by oxygen removal or addition of azide or beta-carotene, and was enhanced by D2O, consistent with partial involvement of singlet oxygen. A direct interaction between the viral fusion protein and the photoactivated dye is also possible.

    This natural polycyclic anthrone, first isolated from the plant St. Johnswort manifested is a strong photosensitizing lipophilic virucidal agent. Its effectivity was found upon influenza A virus, Sendai virus, VSV, HIV and other retroviruses (murine Friend leukemia virus, radiation leukemia virus and Moloney mouse leukemia virus, equine infectious anemia virus), HSV-1, HSV-2 and vaccinia virus. The compound photodynamic virucidal efficiency vs. HIV and VSV was found at nanomolar coincentration. Hyperacin did not showed selective antiviral activity against HSV, influenza A, adeno- or poliovirus. When virus was incubated hypericin before infecting cells, the drug was virucidal to all enveloped viruses tested (influenza A, Moloney mouse leukemia virus, HSV). The compound was not virucidal to the none-enveloped viruses (polio, human rhinovirus, adeno) tested. Evidently, the mechanism of viral inactivation for hypericin is dependent upon the presence of a viral lipid envelope. The chemiluminescent oxidation of luciferin by a plant luciferase was found to generate sufficiently intense and long- lived emission to induce virucidal activity of hypericin. Hypericin bind cellmembranes (and by inference, virus membranes) and crosslinks virus capsid proteins. Its anti-retrovirus action results in a loss of infectivity and an inability to retrieve the reverse transcriptase enzymatic activity from the virion. Hypericin is convinient for use as virucidal (vs. HIV) treatment of blood products. Addition of small amounts of Tween-80 to solutions containing hypericin enhanced by up to 2.6 lg hypericin’s virucidal activity.

    Hypocrellin A
    This compound displays photoinduced virucidal activity, in particular against HIV. Hypocrellin A like hypericin executes an excited-state intramolecular proton transfer, and defferes from hypericin in two important ways: a. hypocrellin A absolutely requires oxigen for its virucidal activity; b. hypocrellin A does not acidify its surrounding medium in the presence of light.

    Anthraquinones Extracted From Plants
    Several virucidal compounds from this class were isolated from different plants (Rheum officinale , Aloe barbadensis, Rhamnus frangula, Rhamnus purshuanus, Cassia angustifolia), namely emodin, aloe-emodin, emodin anthrone and emodin bianthrone. Hypericin is also a member of this class. Their virucidal spectrum envolves a large scope of enveloped viruses: influenza, parainfluenza, VSV, herpesviruses HSV-1, HSV-2, VZV and PsRV. The compound effective concentrations were less than 1 mcg/ml in the so-called contact (direct pre-infection incubation) test. The activity of these substances were lower than that of hypericin, By their virucidal effects the compounds could be arranged as follows: emodin bianthrone > emodin anthrone > emodin. Aloe-emodin inactivated all of the viruses mentioned above; adenovirus and rhinovirus were insensitive.

    Sulfonated Anthraquinones And Other Anthraquinone Derivatives
    Anthraquinone derivatives acid blue 40 and 129, acid black 48, alizarin violet R and reactive blue 2 manifested a marked virucidal activity upon human CMV strains.

    Natural products

    This polypeptide antibiotic derived from Bacillus brevis is a weak anti-HIV virucidal (thousand-fold less active than nonoxyol-9 and gossypol [20].

    This substance, a polyphenolic aldehyde extracted from cotton seed, demonstrated several biological effects: a pronounced interferon-inducing activity, a contraceptive (spermicide) and an anti-HIV virucidal effects. The latter was proved in cell-free reverse transcriptase system.

    Garlic (Allium sativum) extract and its components: ajoene, diallyl thiosulfinate (allicin), allyl methyl thioulfinate, methyl allyl thiosulfinate

    Garlic has been shown to have antiviral activity. In the contact test the fresh garlic extract and several garlic associated compounds as mentioned above demonstrated a strong virucidal activity against wide spectrum of viruses - enveloped (parainfluenza virus type 3, VSV, HSV-1, HSV-2), non-enveloped (human rhinovirus type 2) and vaccinia virus as well. The order for virucidal activity of the garlic extract compounds was: ajoene > allicin > allyl methyl thiosulfinate > methyl allyl thiosulfinate. Ajoene was found in oil-macerates of garlic but not in fresh garlic extracts. No activity was found for the garlic polar fraction, alliin, deoxyalliin, diallyl disulfate, and diallyl trisulfate. Fresh garlic extract, in which thiosulfinates appeared to be the active components, was virucidal to each virus mentioned above. Experimental data demonstrated that virucidal activity and cytotoxicity may have dependedupon the viral envelope and cell membrane, respectively.

    Extracts of Ledium, Motherworth, Celandine, Black Currant, Coaberry and Billberry

    The aqueous extracts of these plants manifested a virucidal effect towards tick-born encephalitis virus and induced resistance in mice infected with this virus.

    Extract of Cordia Salicifolia
    A partially purified extract of this plant nas been shown to have a direct virucidal activity against HSV-1, to which could be attributed the inhibitory effect of this extract on viral replication.

    Steam Distillate From Houttuynia Cordata (Saururaceae) and Its Component

    The steam distillate prepared from fresh plants was found to have virucidal activity against several enveloped viruses: influenza A virus, HIV and HSV-1. Three major componenets of the distillate, methyl-n-nonyl ketone, lauryl aldehyde, and capryl aldehyde, also inactivated these viruses. Ithe data obtained demonstrate that the essential oils provide virucidal activity against enveloped viruses by interfering with the function of the virus envelope.

    5,6,7-Trimethoxyflavone from Calicarpa Japonica 

    This naturally occuring flavone exibited relatively high inhibitory effect on replication of poliovirus 1 and herpesviruses HSV-1 and CMV. The anti-HSV-1 action is not due to the inhibition of virus adsorption, entry, and viral protein synthesis, but might involve, at least in part, a virucidal activity, which results in a suppression of viral binding to host cells at an early replication stage.

    Isoscullarein (5,7,8,4’-tetrahydroxyflavone) from Scutellaria baikalensis and isoscutellarein-8-methylether

    These substances isolated from the plant leaf demonstrated both an inhibitory effect on the influenza A virus neuraminidase and a potent virucidal activity against this virus in ovo and in vivo. The virus-inhibitory effect of flavone and methylether were identical, but the flavone’s virucidal activity was stronger.

    Alkaloids and Phytosteryl Ester Compounds
    These substances (marigenol-concentrates comprising taxol and/or taxan esters as active principles) manifested an anti-tumor and antiviral/virucidal activity.

    This was in general lines the virucidal agents’ spectrum before the appearance of the pioneer of a new generation rubs, Manorapid Synergy®. 

    How To Use Virucidal Chemicals And Disinfectants To Kill Viruses

    CDC Guideline for Disinfection and Sterilization in Healthcare Facilities (2008)


    In the healthcare setting, “alcohol” refers to two water-soluble chemical compounds—ethyl alcohol and isopropyl alcohol—that have generally underrated germicidal characteristics. FDA has not cleared any liquid chemical sterilant or high-level disinfectant with alcohol as the main active ingredient. These alcohols are rapidly bactericidal rather than bacteriostatic against vegetative forms of bacteria; they also are tuberculocidal, fungicidal, and virucidal but do not destroy bacterial spores. Their cidal activity drops sharply when diluted below 50% concentration, and the optimum bactericidal concentration is 60%–90% solutions in water (volume/volume).

    Mode of Action.
    The most feasible explanation for the antimicrobial action of alcohol is denaturation of proteins. This mechanism is supported by the observation that absolute ethyl alcohol, a dehydrating agent, is less bactericidal than mixtures of alcohol and water because proteins are denatured more quickly in the presence of water. Protein denaturation also is consistent with observations that alcohol destroys the dehydrogenases of Escherichia coli, and that ethyl alcohol increases the lag phase of Enterobacter aerogenes and that the lag phase effect could be reversed by adding certain amino acids. The bacteriostatic action was believed caused by inhibition of the production of metabolites essential for rapid cell division.

    Microbicidal Activity.
    Methyl alcohol (methanol) has the weakest bactericidal action of the alcohols and thus seldom is used in healthcare. The bactericidal activity of various concentrations of ethyl alcohol (ethanol) was examined against a variety of microorganisms in exposure periods ranging from 10 seconds to 1 hour. Pseudomonas aeruginosa was killed in 10 seconds by all concentrations of ethanol from 30% to 100% (v/v), and Serratia marcescens, E, coli and Salmonella typhosa were killed in 10 seconds by all concentrations of ethanol from 40% to 100%. The gram-positive organisms Staphylococcus aureus and Streptococcus pyogenes were slightly more resistant, being killed in 10 seconds by ethyl alcohol concentrations of 60%–95%. Isopropyl alcohol (isopropanol) was slightly more bactericidal than ethyl alcohol for E. coli and S. aureus.

    Ethyl alcohol, at concentrations of 60%–80%, is a potent virucidal agent inactivating all of the lipophilic viruses (e.g., herpes, vaccinia, and influenza virus) and many hydrophilic viruses (e.g., adenovirus, enterovirus, rhinovirus, and rotaviruses but not hepatitis A virus (HAV) or poliovirus). Isopropyl alcohol is not active against the nonlipid enteroviruses but is fully active against the lipid viruses. Studies also have demonstrated the ability of ethyl and isopropyl alcohol to inactivate the hepatitis B virus(HBV) and the herpes virus, and ethyl alcohol to inactivate human immunodeficiency virus (HIV), rotavirus, echovirus, and astrovirus.

    In tests of the effect of ethyl alcohol against M. tuberculosis, 95% ethanol killed the tubercle bacilli in sputum or water suspension within 15 seconds. In 1964, Spaulding stated that alcohols were the germicide of choice for tuberculocidal activity, and they should be the standard by which all other tuberculocides are compared. For example, he compared the tuberculocidal activity of iodophor (450 ppm), a substituted phenol (3%), and isopropanol (70%/volume) using the mucin-loop test (106 M. tuberculosis per loop) and determined the contact times needed for complete destruction were 120–180 minutes, 45–60 minutes, and 5 minutes, respectively. The mucin-loop test is a severe test developed to produce long survival times. Thus, these figures should not be extrapolated to the exposure times needed when these germicides are used on medical or surgical material.

    Ethyl alcohol (70%) was the most effective concentration for killing the tissue phase of Cryptococcus neoformans, Blastomyces dermatitidis, Coccidioides immitis, and Histoplasma capsulatum and the culture phases of the latter three organisms aerosolized onto various surfaces. The culture phase was more resistant to the action of ethyl alcohol and required about 20 minutes to disinfect the contaminated surface, compared with <1 minute for the tissue phase.

    Isopropyl alcohol (20%) is effective in killing the cysts of Acanthamoeba culbertsoni (560) as are chlorhexidine, hydrogen peroxide, and thimerosal.

    Alcohols are not recommended for sterilizing medical and surgical materials principally because they lack sporicidal action and they cannot penetrate protein-rich materials. Fatal postoperative wound infections with Clostridium have occurred when alcohols were used to sterilize surgical instruments contaminated with bacterial spores. Alcohols have been used effectively to disinfect oral and rectal thermometers, hospital pagers, scissors, and stethoscopes. Alcohols have been used to disinfect fiberoptic endoscopes but failure of this disinfectant have lead to infection. Alcohol towelettes have been used for years to disinfect small surfaces such as rubber stoppers of multiple-dose medication vials or vaccine bottles. Furthermore, alcohol occasionally is used to disinfect external surfaces of equipment (e.g., stethoscopes, ventilators, manual ventilation bags) 506, CPR manikins, ultrasound instruments 508 or medication preparation areas. Two studies demonstrated the effectiveness of 70% isopropyl alcohol to disinfect reusable transducer heads in a controlled environment. In contrast, three bloodstream infection outbreaks have been described when alcohol was used to disinfect transducer heads in an intensive-care setting.

    The documented shortcomings of alcohols on equipment are that they damage the shellac mountings of lensed instruments, tend to swell and harden rubber and certain plastic tubing after prolonged and repeated use, bleach rubber and plastic tiles and damage tonometer tips (by deterioration of the glue) after the equivalent of 1 working year of routine use. Tonometer biprisms soaked in alcohol for 4 days developed rough front surfaces that potentially could cause corneal damage; this appeared to be caused by weakening of the cementing substances used to fabricate the biprisms. Corneal opacification has been reported when tonometer tips were swabbed with alcohol immediately before measurement of intraocular pressure. Alcohols are flammable and consequently must be stored in a cool, well-ventilated area. They also evaporate rapidly, making extended exposure time difficult to achieve unless the items are immersed.

    Chlorine and Chlorine Compounds

    Hypochlorites, the most widely used of the chlorine disinfectants, are available as liquid (e.g., sodium hypochlorite) or solid (e.g., calcium hypochlorite). The most prevalent chlorine products in the United States are aqueous solutions of 5.25%–6.15% sodium hypochlorite (see glossary), usually called household bleach. They have a broad spectrum of antimicrobial activity, do not leave toxic residues, are unaffected by water hardness, are inexpensive and fast acting, remove dried or fixed organisms and biofilms from surfaces465, and have a low incidence of serious toxicity. Sodium hypochlorite at the concentration used in household bleach (5.25-6.15%) can produce ocular irritation or oropharyngeal, esophageal, and gastric burns. Other disadvantages of hypochlorites include corrosiveness to metals in high concentrations (>500 ppm), inactivation by organic matter, discoloring or “bleaching” of fabrics, release of toxic chlorine gas when mixed with ammonia or acid (e.g., household cleaning agents), and relative stability. The microbicidal activity of chlorine is attributed largely to undissociated hypochlorous acid (HOCl). The dissociation of HOCI to the less microbicidal form (hypochlorite ion OCl‑) depends on pH. The disinfecting efficacy of chlorine decreases with an increase in pH that parallels the conversion of undissociated HOCI to OCl‑. A potential hazard is production of the carcinogen bis(chloromethyl) ether when hypochlorite solutions contact formaldehyde and the production of the animal carcinogen trihalomethane when hot water is hyperchlorinated. After reviewing environmental fate and ecologic data, EPA has determined the currently registered uses of hypochlorites will not result in unreasonable adverse effects to the environment.

    Alternative compounds that release chlorine and are used in the health-care setting include demand-release chlorine dioxide, sodium dichloroisocyanurate, and chloramine-T. The advantage of these compounds over the hypochlorites is that they retain chlorine longer and so exert a more prolonged bactericidal effect. Sodium dichloroisocyanurate tablets are stable, and for two reasons, the microbicidal activity of solutions prepared from sodium dichloroisocyanurate tablets might be greater than that of sodium hypochlorite solutions containing the same total available chlorine. First, with sodium dichloroisocyanurate, only 50% of the total available chlorine is free (HOCl and OCl–), whereas the remainder is combined (monochloroisocyanurate or dichloroisocyanurate), and as free available chlorine is used up, the latter is released to restore the equilibrium. Second, solutions of sodium dichloroisocyanurate are acidic, whereas sodium hypochlorite solutions are alkaline, and the more microbicidal type of chlorine (HOCl) is believed to predominate. Chlorine dioxide-based disinfectants are prepared fresh as required by mixing the two components (base solution [citric acid with preservatives and corrosion inhibitors] and the activator solution [sodium chlorite]). In vitro suspension tests showed that solutions containing about 140 ppm chlorine dioxide achieved a reduction factor exceeding 106 of S. aureus in 1 minute and of Bacillus atrophaeus spores in 2.5 minutes in the presence of 3 g/L bovine albumin. The potential for damaging equipment requires consideration because long-term use can damage the outer plastic coat of the insertion tube. In another study, chlorine dioxide solutions at either 600 ppm or 30 ppm killed Mycobacterium avium-intracellulare within 60 seconds after contact but contamination by organic material significantly affected the microbicidal properties.

    The microbicidal activity of a new disinfectant, “superoxidized water,” has been examined The concept of electrolyzing saline to create a disinfectant or antiseptics is appealing because the basic materials of saline and electricity are inexpensive and the end product (i.e., water) does not damage the environment. The main products of this water are hypochlorous acid (e.g., at a concentration of about 144 mg/L) and chlorine. As with any germicide, the antimicrobial activity of superoxidized water is strongly affected by the concentration of the active ingredient (available free chlorine). One manufacturer generates the disinfectant at the point of use by passing a saline solution over coated titanium electrodes at 9 amps. The product generated has a pH of 5.0–6.5 and an oxidation-reduction potential (redox) of >950 mV. Although superoxidized water is intended to be generated fresh at the point of use, when tested under clean conditions the disinfectant was effective within 5 minutes when 48 hours old. Unfortunately, the equipment required to produce the product can be expensive because parameters such as pH, current, and redox potential must be closely monitored. The solution is nontoxic to biologic tissues. Although the United Kingdom manufacturer claims the solution is noncorrosive and nondamaging to endoscopes and processing equipment, one flexible endoscope manufacturer (Olympus Key-Med, United Kingdom) has voided the warranty on the endoscopes if superoxidized water is used to disinfect them. As with any germicide formulation, the user should check with the device manufacturer for compatibility with the germicide. Additional studies are needed to determine whether this solution could be used as an alternative to other disinfectants or antiseptics for hand washing, skin antisepsis, room cleaning, or equipment disinfection (e.g., endoscopes, dialyzers). In October 2002, the FDA cleared superoxidized water as a high-level disinfectant.

    Mode of Action.
    The exact mechanism by which free chlorine destroys microorganisms has not been elucidated. Inactivation by chlorine can result from a number of factors: oxidation of sulfhydryl enzymes and amino acids; ring chlorination of amino acids; loss of intracellular contents; decreased uptake of nutrients; inhibition of protein synthesis; decreased oxygen uptake; oxidation of respiratory components; decreased adenosine triphosphate production; breaks in DNA; and depressed DNA synthesis. The actual microbicidal mechanism of chlorine might involve a combination of these factors or the effect of chlorine on critical sites.

    Microbicidal Activity.
    Low concentrations of free available chlorine (e.g., HOCl, OCl–, and elemental chlorine-Cl2) have a biocidal effect on mycoplasma (25 ppm) and vegetative bacteria (<5 ppm) in seconds in the absence of an organic load. Higher concentrations (1,000 ppm) of chlorine are required to kill M. tuberculosis using the Association of Official Analytical Chemists (AOAC) tuberculocidal test. A concentration of 100 ppm will kill ≥99.9% of B. atrophaeus spores within 5 minutes and destroy mycotic agents in <1 hour. Acidified bleach and regular bleach (5,000 ppm chlorine) can inactivate Clostridium difficile spores in ≤10 minutes. One study reported that 25 different viruses were inactivated in 10 minutes with 200 ppm available chlorine. Several studies have demonstrated the effectiveness of diluted sodium hypochlorite and other disinfectants to inactivate HIV. Chlorine (500 ppm) showed inhibition of Candida after 30 seconds of exposure. In experiments using the AOAC Use-Dilution Method, 100 ppm of free chlorine killed S. aureus, Salmonella choleraesuis, and P. aeruginosa in <10 minutes. Because household bleach contains 5.25%–6.15% sodium hypochlorite, or 52,500–61,500 ppm available chlorine, a 1:1,000 dilution provides about 53–62 ppm available chlorine, and a 1:10 dilution of household bleach provides about 5250–6150 ppm.

    Data are available for chlorine dioxide that support manufacturers’ bactericidal, fungicidal, sporicidal, tuberculocidal, and virucidal label claims. A chlorine dioxide generator has been shown effective for decontaminating flexible endoscopes but it is not currently FDA-cleared for use as a high-level disinfectant. Chlorine dioxide can be produced by mixing solutions, such as a solution of chlorine with a solution of sodium chlorite. In 1986, a chlorine dioxide product was voluntarily removed from the market when its use caused leakage of cellulose-based dialyzer membranes, which allowed bacteria to migrate from the dialysis fluid side of the dialyzer to the blood side.

    Sodium dichloroisocyanurate at 2,500 ppm available chlorine is effective against bacteria in the presence of up to 20% plasma, compared with 10% plasma for sodium hypochlorite at 2,500 ppm.

    “Superoxidized water” has been tested against bacteria, mycobacteria, viruses, fungi, and spores. Freshly generated superoxidized water is rapidly effective (<2 minutes) in achieving a 5-log10 reduction of pathogenic microorganisms (i.e., M. tuberculosis, M. chelonae, poliovirus, HIV, multidrug-resistant S. aureus, E. coli, Candida albicans, Enterococcus faecalis, P. aeruginosa) in the absence of organic loading. However, the biocidal activity of this disinfectant decreased substantially in the presence of organic material (e.g., 5% horse serum). No bacteria or viruses were detected on artificially contaminated endoscopes after a 5-minute exposure to superoxidized water 551 and HBV-DNA was not detected from any endoscope experimentally contaminated with HBV-positive mixed sera after a disinfectant exposure time of 7 minutes.

    Hypochlorites are widely used in healthcare facilities in a variety of settings. 328 Inorganic chlorine solution is used for disinfecting tonometer heads and for spot-disinfection of countertops and floors. A 1:10–1:100 dilution of 5.25%–6.15% sodium hypochlorite (i.e., household bleach) or an EPA-registered tuberculocidal disinfectant 17has been recommended for decontaminating blood spills. For small spills of blood (i.e., drops of blood) on noncritical surfaces, the area can be disinfected with a 1:100 dilution of 5.25%-6.15% sodium hypochlorite or an EPA-registered tuberculocidal disinfectant. Because hypochlorites and other germicides are substantially inactivated in the presence of blood, large spills of blood require that the surface be cleaned before an EPA-registered disinfectant or a 1:10 (final concentration) solution of household bleach is applied. If a sharps injury is possible, the surface initially should be decontaminated, then cleaned and disinfected (1:10 final concentration). Extreme care always should be taken to prevent percutaneous injury. At least 500 ppm available chlorine for 10 minutes is recommended for decontaminating CPR training manikins. Full-strength bleach has been recommended for self-disinfection of needles and syringes used for illicit-drug injection when needle-exchange programs are not available. The difference in the recommended concentrations of bleach reflects the difficulty of cleaning the interior of needles and syringes and the use of needles and syringes for parenteral injection. Clinicians should not alter their use of chlorine on environmental surfaces on the basis of testing methodologies that do not simulate actual disinfection practices. Other uses in healthcare include as an irrigating agent in endodontic treatment and as a disinfectant for manikins, laundry, dental appliances, hydrotherapy tanks, regulated medical waste before disposal, and the water distribution system in hemodialysis centers and hemodialysis machines.

    Chlorine long has been used as the disinfectant in water treatment. Hyperchlorination of a Legionella-contaminated hospital water system resulted in a dramatic decrease (from 30% to 1.5%) in the isolation of L. pneumophila from water outlets and a cessation of healthcare-associated Legionnaires’ disease in an affected unit. Water disinfection with monochloramine by municipal water-treatment plants substantially reduced the risk for healthcare–associated Legionnaires disease. Chlorine dioxide also has been used to control Legionella in a hospital water supply. Chloramine T and hypochlorites have been used to disinfect hydrotherapy equipment.

    Hypochlorite solutions in tap water at a pH >8 stored at room temperature (23°C) in closed, opaque plastic containers can lose up to 40%–50% of their free available chlorine level over 1 month. Thus, if a user wished to have a solution containing 500 ppm of available chlorine at day 30, he or she should prepare a solution containing 1,000 ppm of chlorine at time 0. Sodium hypochlorite solution does not decompose after 30 days when stored in a closed brown bottle.

    The use of powders, composed of a mixture of a chlorine-releasing agent with highly absorbent resin, for disinfecting spills of body fluids has been evaluated by laboratory tests and hospital ward trials. The inclusion of acrylic resin particles in formulations markedly increases the volume of fluid that can be soaked up because the resin can absorb 200–300 times its own weight of fluid, depending on the fluid consistency. When experimental formulations containing 1%, 5%, and 10% available chlorine were evaluated by a standardized surface test, those containing 10% demonstrated bactericidal activity. One problem with chlorine-releasing granules is that they can generate chlorine fumes when applied to urine.


    Formaldehyde is used as a disinfectant and sterilant in both its liquid and gaseous states. Liquid formaldehyde will be considered briefly in this section, and the gaseous form is reviewed elsewhere. Formaldehyde is sold and used principally as a water-based solution called formalin, which is 37% formaldehyde by weight. The aqueous solution is a bactericide, tuberculocide, fungicide, virucide and sporicide. OSHA indicated that formaldehyde should be handled in the workplace as a potential carcinogen and set an employee exposure standard for formaldehyde that limits an 8-hour time-weighted average exposure concentration of 0.75 ppm. The standard includes a second permissible exposure limit in the form of a short-term exposure limit (STEL) of 2 ppm that is the maximum exposure allowed during a 15-minute period. Ingestion of formaldehyde can be fatal, and long-term exposure to low levels in the air or on the skin can cause asthma-like respiratory problems and skin irritation, such as dermatitis and itching. For these reasons, employees should have limited direct contact with formaldehyde, and these considerations limit its role in sterilization and disinfection processes. Key provisions of the OSHA standard that protects workers from exposure to formaldehyde appear in Title 29 of the Code of Federal Regulations (CFR) Part 1910.1048 (and equivalent regulations in states with OSHA-approved state plans).

    Mode of Action.
    Formaldehyde inactivates microorganisms by alkylating the amino and sulfhydral groups of proteins and ring nitrogen atoms of purine bases.

    Microbicidal Activity.
    Varying concentrations of aqueous formaldehyde solutions destroy a wide range of microorganisms. Inactivation of poliovirus in 10 minutes required an 8% concentration of formalin, but all other viruses tested were inactivated with 2% formalin. Four percent formaldehyde is a tuberculocidal agent, inactivating M. tuberculosis in 2 minutes, and 2.5% formaldehyde inactivated about Salmonella Typhi in 10 minutes in the presence of organic matter. The sporicidal action of formaldehyde was slower than that of glutaraldehyde in comparative tests with 4% aqueous formaldehyde and 2% glutaraldehyde against the spores of B. anthracis. The formaldehyde solution required 2 hours of contact to achieve an inactivation factor of 104, whereas glutaraldehyde required only 15 minutes.

    Although formaldehyde-alcohol is a chemical sterilant and formaldehyde is a high-level disinfectant, the health-care uses of formaldehyde are limited by its irritating fumes and its pungent odor even at very low levels (<1 ppm). For these reasons and others—such as its role as a suspected human carcinogen linked to nasal cancer and lung cancer, this germicide is excluded from Table 1. When it is used, , direct exposure to employees generally is limited; however, excessive exposures to formaldehyde have been documented for employees of renal transplant units, and students in a gross anatomy laboratory. Formaldehyde is used in the health-care setting to prepare viral vaccines (e.g., poliovirus and influenza); as an embalming agent; and to preserve anatomic specimens; and historically has been used to sterilize surgical instruments, especially when mixed with ethanol. A 1997 survey found that formaldehyde was used for reprocessing hemodialyzers by 34% of U.S. hemodialysis centers—a 60% decrease from 1983. If used at room temperature, a concentration of 4% with a minimum exposure of 24 hours is required to disinfect disposable hemodialyzers reused on the same patient. Aqueous formaldehyde solutions (1%–2%) also have been used to disinfect the internal fluid pathways of dialysis machines. To minimize a potential health hazard to dialysis patients, the dialysis equipment must be thoroughly rinsed and tested for residual formaldehyde before use.

    Paraformaldehyde, a solid polymer of formaldehyde, can be vaporized by heat for the gaseous decontamination of laminar flow biologic safety cabinets when maintenance work or filter changes require access to the sealed portion of the cabinet.


    Glutaraldehyde is a saturated dialdehyde that has gained wide acceptance as a high-level disinfectant and chemical sterilant. Aqueous solutions of glutaraldehyde are acidic and generally in this state are not sporicidal. Only when the solution is “activated” (made alkaline) by use of alkalinating agents to pH 7.5–8.5 does the solution become sporicidal. Once activated, these solutions have a shelf-life of minimally 14 days because of the polymerization of the glutaraldehyde molecules at alkaline pH levels. This polymerization blocks the active sites (aldehyde groups) of the glutaraldehyde molecules that are responsible for its biocidal activity.

    Novel glutaraldehyde formulations (e.g., glutaraldehyde-phenol-sodium phenate, potentiated acid glutaraldehyde, stabilized alkaline glutaraldehyde) produced in the past 30 years have overcome the problem of rapid loss of activity (e.g., use-life 28–30 days) while generally maintaining excellent microbicidal activity. However, antimicrobial activity depends not only on age but also on use conditions, such as dilution and organic stress. Manufacturers’ literature for these preparations suggests the neutral or alkaline glutaraldehydes possess microbicidal and anticorrosion properties superior to those of acid glutaraldehydes, and a few published reports substantiate these claims. However, two studies found no difference in the microbicidal activity of alkaline and acid glutaraldehydes. The use of glutaraldehyde-based solutions in health-care facilities is widespread because of their advantages, including excellent biocidal properties; activity in the presence of organic matter (20% bovine serum); and noncorrosive action to endoscopic equipment, thermometers, rubber, or plastic equipment.

    Mode of Action.
    The biocidal activity of glutaraldehyde results from its alkylation of sulfhydryl, hydroxyl, carboxyl, and amino groups of microorganisms, which alters RNA, DNA, and protein synthesis. The mechanism of action of glutaraldehydes are reviewed extensively elsewhere.

    Microbicidal Activity.
    The in vitro inactivation of microorganisms by glutaraldehydes has been extensively investigated and reviewed. Several investigators showed that ≥2% aqueous solutions of glutaraldehyde, buffered to pH 7.5–8.5 with sodium bicarbonate effectively killed vegetative bacteria in <2 minutes; M. tuberculosis, fungi, and viruses in <10 minutes; and spores of Bacillus and Clostridium species in 3 hours. Spores of C. difficile are more rapidly killed by 2% glutaraldehyde than are spores of other species of Clostridium and Bacillus. Microorganisms with substantial resistance to glutaraldehyde have been reported, including some mycobacteria (M. chelonae, Mycobacterium avium-intracellulare, M. xenopi), Methylobacterium mesophilicum, Trichosporon, fungal ascospores (e.g., Microascus cinereus, Cheatomium globosum), and Cryptosporidium. M. chelonae persisted in a 0.2% glutaraldehyde solution used to store porcine prosthetic heart valves.

    Two percent alkaline glutaraldehyde solution inactivated M. tuberculosis cells on the surface of penicylinders within 5 minutes at 18°C. However, subsequent studies questioned the mycobactericidal prowess of glutaraldehydes. Two percent alkaline glutaraldehyde has slow action (20 to >30 minutes) against M. tuberculosis and compares unfavorably with alcohols, formaldehydes, iodine, and phenol 82. Suspensions of M. avium, M. intracellulare, and M. gordonae were more resistant to inactivation by a 2% alkaline glutaraldehyde (estimated time to complete inactivation: ~60 minutes) than were virulent M. tuberculosis (estimated time to complete inactivation ~25 minutes). The rate of kill was directly proportional to the temperature, and a standardized suspension of M. tuberculosis could not be sterilized within 10 minutes. An FDA-cleared chemical sterilant containing 2.5% glutaraldehyde uses increased temperature (35°C) to reduce the time required to achieve high-level disinfection (5 minutes), but its use is limited to automatic endoscope reprocessors equipped with a heater. In another study employing membrane filters for measurement of mycobactericidal activity of 2% alkaline glutaraldehyde, complete inactivation was achieved within 20 minutes at 20°C when the test inoculum was 106 M. tuberculosis per membrane 81. Several investigators have demonstrated that glutaraldehyde solutions inactivate 2.4 to >5.0 log10 of M. tuberculosis in 10 minutes (including multidrug-resistant M. tuberculosis) and 4.0–6.4 log10 of M. tuberculosis in 20 minutes. On the basis of these data and other studies, 20 minutes at room temperature is considered the minimum exposure time needed to reliably kill Mycobacteria and other vegetative bacteria with ≥2% glutaraldehyde.

    Glutaraldehyde is commonly diluted during use, and studies showed a glutaraldehyde concentration decline after a few days of use in an automatic endoscope washer. The decline occurs because instruments are not thoroughly dried and water is carried in with the instrument, which increases the solution’s volume and dilutes its effective concentration. This emphasizes the need to ensure that semicritical equipment is disinfected with an acceptable concentration of glutaraldehyde. Data suggest that 1.0%–1.5% glutaraldehyde is the minimum effective concentration for >2% glutaraldehyde solutions when used as a high-level disinfectant. Chemical test strips or liquid chemical monitors are available for determining whether an effective concentration of glutaraldehyde is present despite repeated use and dilution. The frequency of testing should be based on how frequently the solutions are used (e.g., used daily, test daily; used weekly, test before use; used 30 times per day, test each 10th use), but the strips should not be used to extend the use life beyond the expiration date. Data suggest the chemicals in the test strip deteriorate with time and a manufacturer’s expiration date should be placed on the bottles. The bottle of test strips should be dated when opened and used for the period of time indicated on the bottle (e.g., 120 days). The results of test strip monitoring should be documented. The glutaraldehyde test kits have been preliminarily evaluated for accuracy and range but the reliability has been questioned. To ensure the presence of minimum effective concentration of the high-level disinfectant, manufacturers of some chemical test strips recommend the use of quality-control procedures to ensure the strips perform properly. If the manufacturer of the chemical test strip recommends a quality-control procedure, users should comply with the manufacturer’s recommendations. The concentration should be considered unacceptable or unsafe when the test indicates a dilution below the product’s minimum effective concentration (MEC) (generally to ≤1.0%–1.5% glutaraldehyde) by the indicator not changing color.

    A 2.0% glutaraldehyde–7.05% phenol–1.20% sodium phenate product that contained 0.125% glutaraldehyde–0.44% phenol–0.075% sodium phenate when diluted 1:16 is not recommended as a high-level disinfectant because it lacks bactericidal activity in the presence of organic matter and lacks tuberculocidal, fungicidal, virucidal, and sporicidal activity. In December 1991, EPA issued an order to stop the sale of all batches of this product because of efficacy data showing the product is not effective against spores and possibly other microorganisms or inanimate objects as claimed on the label. FDA has cleared a glutaraldehyde–phenol/phenate concentrate as a high-level disinfectant that contains 1.12% glutaraldehyde with 1.93% phenol/phenate at its use concentration. Other FDA cleared glutaraldehyde sterilants that contain 2.4%–3.4% glutaraldehyde are used undiluted.

    Glutaraldehyde is used most commonly as a high-level disinfectant for medical equipment such as endoscopes, spirometry tubing, dialyzers, transducers, anesthesia and respiratory therapy equipment, hemodialysis proportioning and dialysate delivery systems, and reuse of laparoscopic disposable plastic trocars. Glutaraldehyde is noncorrosive to metal and does not damage lensed instruments, rubber. or plastics. Glutaraldehyde should not be used for cleaning noncritical surfaces because it is too toxic and expensive.

    Colitis believed caused by glutaraldehyde exposure from residual disinfecting solution in endoscope solution channels has been reported and is preventable by careful endoscope rinsing. One study found that residual glutaraldehyde levels were higher and more variable after manual disinfection (<0.2 mg/L to 159.5 mg/L) than after automatic disinfection (0.2–6.3 mg/L). Similarly, keratopathy and corneal decompensation were caused by ophthalmic instruments that were inadequately rinsed after soaking in 2% glutaraldehyde.

    Healthcare personnel can be exposed to elevated levels of glutaraldehyde vapor when equipment is processed in poorly ventilated rooms, when spills occur, when glutaraldehyde solutions are activated or changed, or when open immersion baths are used. Acute or chronic exposure can result in skin irritation or dermatitis, mucous membrane irritation (eye, nose, mouth), or pulmonary symptoms. Epistaxis, allergic contact dermatitis, asthma, and rhinitis also have been reported in healthcare workers exposed to glutaraldehyde.

    Glutaraldehyde exposure should be monitored to ensure a safe work environment. Testing can be done by four techniques: a silica gel tube/gas chromatography with a flame ionization detector, dinitrophenylhydrazine (DNPH)-impregnated filter cassette/high-performance liquid chromatography (HPLC) with an ultraviolet (UV) detector, a passive badge/HPLC, or a handheld glutaraldehyde air monitor. The silica gel tube and the DNPH-impregnated cassette are suitable for monitoring the 0.05 ppm ceiling limit. The passive badge, with a 0.02 ppm limit of detection, is considered marginal at the Americal Council of Governmental Industrial Hygienists (ACGIH) ceiling level. The ceiling level is considered too close to the glutaraldehyde meter’s 0.03 ppm limit of detection to provide confidence in the readings. ACGIH does not require a specific monitoring schedule for glutaraldehyde; however, a monitoring schedule is needed to ensure the level is less than the ceiling limit. For example, monitoring should be done initially to determine glutaraldehyde levels, after procedural or equipment changes, and in response to worker complaints. In the absence of an OSHA permissible exposure limit, if the glutaraldehyde level is higher than the ACGIH ceiling limit of 0.05 ppm, corrective action and repeat monitoring would be prudent.

    Engineering and work-practice controls that can be used to resolve these problems include ducted exhaust hoods, air systems that provide 7–15 air exchanges per hour, ductless fume hoods with absorbents for the glutaraldehyde vapor, tight-fitting lids on immersion baths, personal protection (e.g., nitrile or butyl rubber gloves but not natural latex gloves, goggles) to minimize skin or mucous membrane contact, and automated endoscope processors. If engineering controls fail to maintain levels below the ceiling limit, institutions can consider the use of respirators (e.g., a half-face respirator with organic vapor cartridge or a type “C” supplied air respirator with a full facepiece operated in a positive pressure mode). In general, engineering controls are preferred over work-practice and administrative controls because they do not require active participation by the health-care worker. Even though enforcement of the OSHA ceiling limit was suspended in 1993 by the U.S. Court of Appeals, limiting employee exposure to 0.05 ppm (according to ACGIH) is prudent because, at this level, glutaraldehyde can irritate the eyes, throat, and nose. If glutaraldehyde disposal through the sanitary sewer system is restricted, sodium bisulfate can be used to neutralize the glutaraldehyde and make it safe for disposal.

    Hydrogen Peroxide

    The literature contains several accounts of the properties, germicidal effectiveness, and potential uses for stabilized hydrogen peroxide in the health-care setting. Published reports ascribe good germicidal activity to hydrogen peroxide and attest to its bactericidal, virucidal, sporicidal, and fungicidal properties. (Tables 4 and 5) The FDA website lists cleared liquid chemical sterilants and high-level disinfectants containing hydrogen peroxide and their cleared contact conditions.

    Mode of Action
    Hydrogen peroxide works by producing destructive hydroxyl free radicals that can attack membrane lipids, DNA, and other essential cell components. Catalase, produced by aerobic organisms and facultative anaerobes that possess cytochrome systems, can protect cells from metabolically produced hydrogen peroxide by degrading hydrogen peroxide to water and oxygen. This defense is overwhelmed by the concentrations used for disinfection.

    Microbicidal Activity.
    Hydrogen peroxide is active against a wide range of microorganisms, including bacteria, yeasts, fungi, viruses, and spores. A 0.5% accelerated hydrogen peroxide demonstrated bactericidal and virucidal activity in 1 minute and mycobactericidal and fungicidal activity in 5 minutes 656. Bactericidal effectiveness and stability of hydrogen peroxide in urine has been demonstrated against a variety of health-care–associated pathogens; organisms with high cellular catalase activity (e.g., S. aureus, S. marcescens, and Proteus mirabilis) required 30–60 minutes of exposure to 0.6% hydrogen peroxide for a reduction in cell counts, whereas organisms with lower catalase activity (e.g., E. coli, Streptococcus species, and Pseudomonas species) required only 15 minutes’ exposure. In an investigation of 3%, 10%, and 15% hydrogen peroxide for reducing spacecraft bacterial populations, a complete kill of 106 spores (i.e., Bacillus species) occurred with a 10% concentration and a 60-minute exposure time. A 3% concentration for 150 minutes killed spores in six of seven exposure trials. A 10% hydrogen peroxide solution resulted in a 103 decrease in B. atrophaeus spores, and a ≥105 decrease when tested against 13 other pathogens in 30 minutes at 20°C. A 3.0% hydrogen peroxide solution was ineffective against VRE after 3 and 10 minutes exposure times and caused only a 2-log10 reduction in the number of Acanthamoeba cysts in approximately 2 hours. A 7% stabilized hydrogen peroxide proved to be sporicidal (6 hours of exposure), mycobactericidal (20 minutes), fungicidal (5 minutes) at full strength, virucidal (5 minutes) and bactericidal (3 minutes) at a 1:16 dilution when a quantitative carrier test was used. The 7% solution of hydrogen peroxide, tested after 14 days of stress (in the form of germ-loaded carriers and respiratory therapy equipment), was sporicidal (>7 log10 reduction in 6 hours), mycobactericidal (>6.5 log10 reduction in 25 minutes), fungicidal (>5 log10 reduction in 20 minutes), bactericidal (>6 log10 reduction in 5 minutes) and virucidal (5 log10 reduction in 5 minutes). Synergistic sporicidal effects were observed when spores were exposed to a combination of hydrogen peroxide (5.9%–23.6%) and peracetic acid. Other studies demonstrated the antiviral activity of hydrogen peroxide against rhinovirus. The time required for inactivating three serotypes of rhinovirus using a 3% hydrogen peroxide solution was 6–8 minutes; this time increased with decreasing concentrations (18-20 minutes at 1.5%, 50–60 minutes at 0.75%).

    Concentrations of hydrogen peroxide from 6% to 25% show promise as chemical sterilants. The product marketed as a sterilant is a premixed, ready-to-use chemical that contains 7.5% hydrogen peroxide and 0.85% phosphoric acid (to maintain a low pH). The mycobactericidal activity of 7.5% hydrogen peroxide has been corroborated in a study showing the inactivation of >105 multidrug-resistant M. tuberculosis after a 10-minute exposure. Thirty minutes were required for >99.9% inactivation of poliovirus and HAV. Three percent and 6% hydrogen peroxide were unable to inactivate HAV in 1 minute in a carrier test. When the effectiveness of 7.5% hydrogen peroxide at 10 minutes was compared with 2% alkaline glutaraldehyde at 20 minutes in manual disinfection of endoscopes, no significant difference in germicidal activity was observed. No complaints were received from the nursing or medical staff regarding odor or toxicity. In one study, 6% hydrogen peroxide (unused product was 7.5%) was more effective in the high-level disinfection of flexible endoscopes than was the 2% glutaraldehyde solution. A new, rapid-acting 13.4% hydrogen peroxide formulation (that is not yet FDA-cleared) has demonstrated sporicidal, mycobactericidal, fungicidal, and virucidal efficacy. Manufacturer data demonstrate that this solution sterilizes in 30 minutes and provides high-level disinfection in 5 minutes. This product has not been used long enough to evaluate material compatibility to endoscopes and other semicritical devices, and further assessment by instrument manufacturers is needed.

    Under normal conditions, hydrogen peroxide is extremely stable when properly stored (e.g., in dark containers). The decomposition or loss of potency in small containers is less than 2% per year at ambient temperatures.

    Commercially available 3% hydrogen peroxide is a stable and effective disinfectant when used on inanimate surfaces. It has been used in concentrations from 3% to 6% for disinfecting soft contact lenses (e.g., 3% for 2–3 hrs), tonometer biprisms, ventilators, fabrics, and endoscopes. Hydrogen peroxide was effective in spot-disinfecting fabrics in patients’ rooms. Corneal damage from a hydrogen peroxide-soaked tonometer tip that was not properly rinsed has been reported. Hydrogen peroxide also has been instilled into urinary drainage bags in an attempt to eliminate the bag as a source of bladder bacteriuria and environmental contamination. Although the instillation of hydrogen peroxide into the bag reduced microbial contamination of the bag, this procedure did not reduce the incidence of catheter-associated bacteriuria.

    A chemical irritation resembling pseudomembranous colitis caused by either 3% hydrogen peroxide or a 2% glutaraldehyde has been reported. An epidemic of pseudomembrane-like enteritis and colitis in seven patients in a gastrointestinal endoscopy unit also has been associated with inadequate rinsing of 3% hydrogen peroxide from the endoscope.

    As with other chemical sterilants, dilution of the hydrogen peroxide must be monitored by regularly testing the minimum effective concentration (i.e., 7.5%–6.0%). Compatibility testing by Olympus America of the 7.5% hydrogen peroxide found both cosmetic changes (e.g., discoloration of black anodized metal finishes) and functional changes with the tested endoscopes.


    Iodine solutions or tinctures long have been used by health professionals primarily as antiseptics on skin or tissue. Iodophors, on the other hand, have been used both as antiseptics and disinfectants. FDA has not cleared any liquid chemical sterilant or high-level disinfectants with iodophors as the main active ingredient. An iodophor is a combination of iodine and a solubilizing agent or carrier; the resulting complex provides a sustained-release reservoir of iodine and releases small amounts of free iodine in aqueous solution. The best-known and most widely used iodophor is povidone-iodine, a compound of polyvinylpyrrolidone with iodine. This product and other iodophors retain the germicidal efficacy of iodine but unlike iodine generally are nonstaining and relatively free of toxicity and irritancy.

    Several reports that documented intrinsic microbial contamination of antiseptic formulations of povidone-iodine and poloxamer-iodine caused a reappraisal of the chemistry and use of iodophors682. “Free” iodine (I2) contributes to the bactericidal activity of iodophors and dilutions of iodophors demonstrate more rapid bactericidal action than does a full-strength povidone-iodine solution. The reason for the observation that dilution increases bactericidal activity is unclear, but dilution of povidone-iodine might weaken the iodine linkage to the carrier polymer with an accompanying increase of free iodine in solution. Therefore, iodophors must be diluted according to the manufacturers’ directions to achieve antimicrobial activity.

    Mode of Action.
    Iodine can penetrate the cell wall of microorganisms quickly, and the lethal effects are believed to result from disruption of protein and nucleic acid structure and synthesis.

    Microbicidal Activity.
    Published reports on the in vitro antimicrobial efficacy of iodophors demonstrate that iodophors are bactericidal, mycobactericidal, and virucidal but can require prolonged contact times to kill certain fungi and bacterial spores. Three brands of povidone-iodine solution have demonstrated more rapid kill (seconds to minutes) of S. aureus and M. chelonae at a 1:100 dilution than did the stock solution. The virucidal activity of 75–150 ppm available iodine was demonstrated against seven viruses. Other investigators have questioned the efficacy of iodophors against poliovirus in the presence of organic matter and rotavirus SA-11 in distilled or tapwater. Manufacturers’ data demonstrate that commercial iodophors are not sporicidal, but they are tuberculocidal, fungicidal, virucidal, and bactericidal at their recommended use-dilution.

    Besides their use as an antiseptic, iodophors have been used for disinfecting blood culture bottles and medical equipment, such as hydrotherapy tanks, thermometers, and endoscopes. Antiseptic iodophors are not suitable for use as hard-surface disinfectants because of concentration differences. Iodophors formulated as antiseptics contain less free iodine than do those formulated as disinfectants. Iodine or iodine-based antiseptics should not be used on silicone catheters because they can adversely affect the silicone tubing.

    Ortho-phthalaldehyde (OPA)

    Ortho-phthalaldehyde is a high-level disinfectant that received FDA clearance in October 1999. It contains 0.55% 1,2-benzenedicarboxaldehyde (OPA). OPA solution is a clear, pale-blue liquid with a pH of 7.5.

    Mode of Action.
    Preliminary studies on the mode of action of OPA suggest that both OPA and glutaraldehyde interact with amino acids, proteins, and microorganisms. However, OPA is a less potent cross-linking agent. This is compensated for by the lipophilic aromatic nature of OPA that is likely to assist its uptake through the outer layers of mycobacteria and gram-negative bacteria. OPA appears to kill spores by blocking the spore germination process.

    Microbicidal Activity.
    Studies have demonstrated excellent microbicidal activity in vitro. For example, OPA has superior mycobactericidal activity (5-log10 reduction in 5 minutes) to glutaraldehyde. The mean times required to produce a 6-log10 reduction for M. bovis using 0.21% OPA was 6 minutes, compared with 32 minutes using 1.5% glutaraldehyde. OPA showed good activity against the mycobacteria tested, including the glutaraldehyde-resistant strains, but 0.5% OPA was not sporicidal with 270 minutes of exposure. Increasing the pH from its unadjusted level (about 6.5) to pH 8 improved the sporicidal activity of OPA. The level of biocidal activity was directly related to the temperature. A greater than 5-log10 reduction of B. atrophaeus spores was observed in 3 hours at 35°C, than in 24 hours at 20°C. Also, with an exposure time ≤5 minutes, biocidal activity decreased with increasing serum concentration. However, efficacy did not differ when the exposure time was ≥10 minutes. In addition, OPA is effective (>5-log10 reduction) against a wide range of microorganisms, including glutaraldehyde-resistant mycobacteria and B. atrophaeus spores.

    The influence of laboratory adaptation of test strains, such as P. aeruginosa, to 0.55% OPA has been evaluated. Resistant and multiresistant strains increased substantially in susceptibility to OPA after laboratory adaptation (log10 reduction factors increased by 0.54 and 0.91 for resistant and multiresistant strains, respectively). Other studies have found naturally occurring cells of P. aeurginosa were more resistant to a variety of disinfectants than were subcultured cells.

    OPA has several potential advantages over glutaraldehyde. It has excellent stability over a wide pH range (pH 3–9), is not a known irritant to the eyes and nasal passages, does not require exposure monitoring, has a barely perceptible odor, and requires no activation. OPA, like glutaraldehyde, has excellent material compatibility. A potential disadvantage of OPA is that it stains proteins gray (including unprotected skin) and thus must be handled with caution. However, skin staining would indicate improper handling that requires additional training and/or personal protective equipment (e.g., gloves, eye and mouth protection, and fluid-resistant gowns). OPA residues remaining on inadequately water-rinsed transesophageal echo probes can stain the patient’s mouth. Meticulous cleaning, using the correct OPA exposure time (e.g., 12 minutes) and copious rinsing of the probe with water should eliminate this problem. The results of one study provided a basis for a recommendation that rinsing of instruments disinfected with OPA will require at least 250 mL of water per channel to reduce the chemical residue to a level that will not compromise patient or staff safety (<1 ppm). Personal protective equipment should be worn when contaminated instruments, equipment, and chemicals are handled. In addition, equipment must be thoroughly rinsed to prevent discoloration of a patient’s skin or mucous membrane.

    In April 2004, the manufacturer of OPA disseminated information to users about patients who reportedly experienced an anaphylaxis-like reaction after cystoscopy where the scope had been reprocessed using OPA. Of approximately 1 million urologic procedures performed using instruments reprocessed using OPA, 24 cases (17 cases in the United States, six in Japan, one in the United Kingdom) of anaphylaxis-like reactions have been reported after repeated cystoscopy (typically after four to nine treatments). Preventive measures include removal of OPA residues by thorough rinsing and not using OPA for reprocessing urologic instrumentation used to treat patients with a history of bladder cancer. 

    A few OPA clinical studies are available. In a clinical-use study, OPA exposure of 100 endoscopes for 5 minutes resulted in a >5-log10 reduction in bacterial load. Furthermore, OPA was effective over a 14-day use cycle 100. Manufacturer data show that OPA will last longer in an automatic endoscope reprocessor before reaching its MEC limit (MEC after 82 cycles) than will glutaraldehyde (MEC after 40 cycles). High-pressure liquid chromatography confirmed that OPA levels are maintained above 0.3% for at least 50 cycles. OPA must be disposed in accordance with local and state regulations. If OPA disposal through the sanitary sewer system is restricted, glycine (25 grams/gallon) can be used to neutralize the OPA and make it safe for disposal.

    The high-level disinfectant label claims for OPA solution at 20°C vary worldwide (e.g., 5 minutes in Europe, Asia, and Latin America; 10 minutes in Canada and Australia; and 12 minutes in the United States). These label claims differ worldwide because of differences in the test methodology and requirements for licensure. In an automated endoscope reprocessor with an FDA-cleared capability to maintain solution temperatures at 25°C, the contact time for OPA is 5 minutes.

    Peracetic Acid

    Peracetic, or peroxyacetic, acid is characterized by rapid action against all microorganisms. Special advantages of peracetic acid are that it lacks harmful decomposition products (i.e., acetic acid, water, oxygen, hydrogen peroxide), enhances removal of organic material, and leaves no residue. It remains effective in the presence of organic matter and is sporicidal even at low temperatures. Peracetic acid can corrode copper, brass, bronze, plain steel, and galvanized iron but these effects can be reduced by additives and pH modifications. It is considered unstable, particularly when diluted; for example, a 1% solution loses half its strength through hydrolysis in 6 days, whereas 40% peracetic acid loses 1%–2% of its active ingredients per month.

    Mode of Action.
    Little is known about the mechanism of action of peracetic acid, but it is believed to function similarly to other oxidizing agents—that is, it denatures proteins, disrupts the cell wall permeability, and oxidizes sulfhydryl and sulfur bonds in proteins, enzymes, and other metabolites.

    Microbicidal Activity.
    Peracetic acid will inactivate gram-positive and gram-negative bacteria, fungi, and yeasts in ≤5 minutes at <100 ppm. In the presence of organic matter, 200–500 ppm is required. For viruses, the dosage range is wide (12–2250 ppm), with poliovirus inactivated in yeast extract in 15 minutes with 1,500–2,250 ppm. In one study, 3.5% peracetic acid was ineffective against HAV after 1-minute exposure using a carrier test. Peracetic acid (0.26%) was effective (log10 reduction factor >5) against all test strains of mycobacteria (M. tuberculosis, M. avium-intracellulare, M. chelonae, and M. fortuitum) within 20–30 minutes in the presence or absence of an organic load. With bacterial spores, 500–10,000 ppm (0.05%–1%) inactivates spores in 15 seconds to 30 minutes using a spore suspension test.

    An automated machine using peracetic acid to chemically sterilize medical (e.g., endoscopes, arthroscopes), surgical, and dental instruments is used in the United States. As previously noted, dental handpieces should be steam sterilized. The sterilant, 35% peracetic acid, is diluted to 0.2% with filtered water at 50°C. Simulated-use trials have demonstrated excellent microbicidal activity, and three clinical trials have demonstrated both excellent microbial killing and no clinical failures leading to infection90. The high efficacy of the system was demonstrated in a comparison of the efficacies of the system with that of ethylene oxide. Only the peracetic acid system completely killed 6 log10 of M. chelonae, E. faecalis, and B. atrophaeus spores with both an organic and inorganic challenge. An investigation that compared the costs, performance, and maintenance of urologic endoscopic equipment processed by high-level disinfection (with glutaraldehyde) with those of the peracetic acid system reported no clinical differences between the two systems. However, the use of this system led to higher costs than the high-level disinfection, including costs for processing ($6.11 vs. $0.45 per cycle), purchasing and training ($24,845 vs. $16), installation ($5,800 vs. $0), and endoscope repairs ($6,037 vs. $445). Furthermore, three clusters of infection using the peracetic acid automated endoscope reprocessor were linked to inadequately processed bronchoscopes when inappropriate channel connectors were used with the system. These clusters highlight the importance of training, proper model-specific endoscope connector systems, and quality-control procedures to ensure compliance with endoscope manufacturer recommendations and professional organization guidelines. An alternative high-level disinfectant available in the United Kingdom contains 0.35% peracetic acid. Although this product is rapidly effective against a broad range of microorganisms, it tarnishes the metal of endoscopes and is unstable, resulting in only a 24-hour use life.

    Peracetic Acid and Hydrogen Peroxide

    Two chemical sterilants are available that contain peracetic acid plus hydrogen peroxide (i.e., 0.08% peracetic acid plus 1.0% hydrogen peroxide [no longer marketed]; and 0.23% peracetic acid plus 7.35% hydrogen peroxide.

    Microbicidal Activity.
    The bactericidal properties of peracetic acid and hydrogen peroxide have been demonstrated. Manufacturer data demonstrated this combination of peracetic acid and hydrogen peroxide inactivated all microorganisms except bacterial spores within 20 minutes. The 0.08% peracetic acid plus 1.0% hydrogen peroxide product effectively inactivated glutaraldehyde-resistant mycobacteria.

    The combination of peracetic acid and hydrogen peroxide has been used for disinfecting hemodialyzers 730. The percentage of dialysis centers using a peracetic acid-hydrogen peroxide-based disinfectant for reprocessing dialyzers increased from 5% in 1983 to 56% in 1997. Olympus America does not endorse use of 0.08% peracetic acid plus 1.0% hydrogen peroxide (Olympus America, personal communication, April 15, 1998) on any Olympus endoscope because of cosmetic and functional damage and will not assume liability for chemical damage resulting from use of this product. This product is not currently available. FDA has cleared a newer chemical sterilant with 0.23% peracetic acid and 7.35% hydrogen peroxide. After testing the 7.35% hydrogen peroxide and 0.23% peracetic acid product, Olympus America concluded it was not compatible with the company’s flexible gastrointestinal endoscopes; this conclusion was based on immersion studies where the test insertion tubes had failed because of swelling and loosening of the black polymer layer of the tube.


    Phenol has occupied a prominent place in the field of hospital disinfection since its initial use as a germicide by Lister in his pioneering work on antiseptic surgery. In the past 30 years, however, work has concentrated on the numerous phenol derivatives or phenolics and their antimicrobial properties. Phenol derivatives originate when a functional group (e.g., alkyl, phenyl, benzyl, halogen) replaces one of the hydrogen atoms on the aromatic ring. Two phenol derivatives commonly found as constituents of hospital disinfectants are ortho-phenylphenol and ortho-benzyl-para-chlorophenol. The antimicrobial properties of these compounds and many other phenol derivatives are much improved over those of the parent chemical. Phenolics are absorbed by porous materials, and the residual disinfectant can irritate tissue. In 1970, depigmentation of the skin was reported to be caused by phenolic germicidal detergents containing para-tertiary butylphenol and para-tertiary amylphenol.

    Mode of Action.
    In high concentrations, phenol acts as a gross protoplasmic poison, penetrating and disrupting the cell wall and precipitating the cell proteins. Low concentrations of phenol and higher molecular-weight phenol derivatives cause bacterial death by inactivation of essential enzyme systems and leakage of essential metabolites from the cell wall.

    Microbicidal Activity.
    Published reports on the antimicrobial efficacy of commonly used phenolics showed they were bactericidal, fungicidal, virucidal, and tuberculocidal. One study demonstrated little or no virucidal effect of a phenolic against coxsackie B4, echovirus 11, and poliovirus 1. Similarly, 12% ortho-phenylphenol failed to inactivate any of the three hydrophilic viruses after a 10-minute exposure time, although 5% phenol was lethal for these viruses. A 0.5% dilution of a phenolic (2.8% ortho-phenylphenol and 2.7% ortho-benzyl-para-chlorophenol) inactivated HIV and a 2% solution of a phenolic (15% ortho-phenylphenol and 6.3% para-tertiary-amylphenol) inactivated all but one of 11 fungi tested.

    Manufacturers’ data using the standardized AOAC methods demonstrate that commercial phenolics are not sporicidal but are tuberculocidal, fungicidal, virucidal, and bactericidal at their recommended use-dilution. Attempts to substantiate the bactericidal label claims of phenolics using the AOAC Use-Dilution Method occasionally have failed. However, results from these same studies have varied dramatically among laboratories testing identical products.

    Many phenolic germicides are EPA-registered as disinfectants for use on environmental surfaces (e.g., bedside tables, bedrails, and laboratory surfaces) and noncritical medical devices. Phenolics are not FDA-cleared as high-level disinfectants for use with semicritical items but could be used to preclean or decontaminate critical and semicritical devices before terminal sterilization or high-level disinfection.

    The use of phenolics in nurseries has been questioned because of hyperbilirubinemia in infants placed in bassinets where phenolic detergents were used. In addition, bilirubin levels were reported to increase in phenolic-exposed infants, compared with nonphenolic-exposed infants, when the phenolic was prepared according to the manufacturers’ recommended dilution. If phenolics are used to clean nursery floors, they must be diluted as recommended on the product label. Phenolics (and other disinfectants) should not be used to clean infant bassinets and incubators while occupied. If phenolics are used to terminally clean infant bassinets and incubators, the surfaces should be rinsed thoroughly with water and dried before reuse of infant bassinets and incubators.

    Quaternary Ammonium Compounds

    The quaternary ammonium compounds are widely used as disinfectants. Health-care–associated infections have been reported from contaminated quaternary ammonium compounds used to disinfect patient-care supplies or equipment, such as cystoscopes or cardiac catheters. The quaternaries are good cleaning agents, but high water hardness and materials such as cotton and gauze pads can make them less microbicidal because of insoluble precipitates or cotton and gauze pads absorb the active ingredients, respectively. One study showed a significant decline (~40%–50% lower at 1 hour) in the concentration of quaternaries released when cotton rags or cellulose-based wipers were used in the open-bucket system, compared with the nonwoven spunlace wipers in the closed-bucket system. As with several other disinfectants (e.g., phenolics, iodophors) gram-negative bacteria can survive or grow in them.

    Chemically, the quaternaries are organically substituted ammonium compounds in which the nitrogen atom has a valence of 5, four of the substituent radicals (R1-R4) are alkyl or heterocyclic radicals of a given size or chain length, and the fifth (X‑) is a halide, sulfate, or similar radical. Each compound exhibits its own antimicrobial characteristics, hence the search for one compound with outstanding antimicrobial properties. Some of the chemical names of quaternary ammonium compounds used in healthcare are alkyl dimethyl benzyl ammonium chloride, alkyl didecyl dimethyl ammonium chloride, and dialkyl dimethyl ammonium chloride. The newer quaternary ammonium compounds (i.e., fourth generation), referred to as twin-chain or dialkyl quaternaries (e.g. didecyl dimethyl ammonium bromide and dioctyl dimethyl ammonium bromide), purportedly remain active in hard water and are tolerant of anionic residues.

    A few case reports have documented occupational asthma as a result of exposure to benzalkonium chloride.

    Mode of Action.
    The bactericidal action of the quaternaries has been attributed to the inactivation of energy-producing enzymes, denaturation of essential cell proteins, and disruption of the cell membrane746. Evidence exists that supports these and other possibilities.

    Microbicidal Activity.
    Results from manufacturers’ data sheets and from published scientific literature indicate that the quaternaries sold as hospital disinfectants are generally fungicidal, bactericidal, and virucidal against lipophilic (enveloped) viruses; they are not sporicidal and generally not tuberculocidal or virucidal against hydrophilic (nonenveloped) viruses. The poor mycobactericidal activities of quaternary ammonium compounds have been demonstrated. Quaternary ammonium compounds (as well as 70% isopropyl alcohol, phenolic, and a chlorine-containing wipe [80 ppm]) effectively (>95%) remove and/or inactivate contaminants (i.e., multidrug-resistant S. aureus, vancomycin-resistant Entercoccus, P. aeruginosa) from computer keyboards with a 5-second application time. No functional damage or cosmetic changes occurred to the computer keyboards after 300 applications of the disinfectants.

    Attempts to reproduce the manufacturers’ bactericidal and tuberculocidal claims using the AOAC tests with a limited number of quaternary ammonium compounds occasionally have failed. However, test results have varied extensively among laboratories testing identical products.

    The quaternaries commonly are used in ordinary environmental sanitation of noncritical surfaces, such as floors, furniture, and walls. EPA-registered quaternary ammonium compounds are appropriate to use for disinfecting medical equipment that contacts intact skin (e.g., blood pressure cuffs). 

    Coronavirus Disease | Symptoms, Prevention And Treatment

    People may be sick with the virus for 1 to 14 days before developing symptoms. The most common symptoms of coronavirus disease (COVID-19) are fever, tiredness, and dry cough. Most people (about 80%) recover from the disease without needing special treatment. More rarely, the disease can be serious and even fatal. Older people, and people with other medical conditions (such as asthma, diabetes, or heart disease), may be more vulnerable to becoming severely ill.

    People may experience:

    • cough
    • fever
    • tiredness
    • difficulty breathing (severe cases)

    You can protect yourself and help prevent spreading the virus to others if you: 

    • Wash your hands regularly for 20 seconds, with soap and water or alcohol-based hand rub
    • Cover your nose and mouth with a disposable tissue or flexed elbow when you cough or sneeze
    • Avoid close contact (1 meter or 3 feet) with people who are unwell
    • Stay home and self-isolate from others in the household if you feel unwell
    • Don't
    • Touch your eyes, nose, or mouth if your hands are not clean

    There is no specific medicine to prevent or treat coronavirus disease (COVID-19). People may need supportive care to help them breathe.

    Self Care

    • If you have mild symptoms, stay at home until you’ve recovered. You can relieve your symptoms if you:
    • rest and sleep
    • keep warm
    • drink plenty of liquids
    • use a room humidifier or take a hot shower to help ease a sore throat and cough

    Medical Treatments 

    If you develop a fever, cough, and have difficulty breathing, promptly seek medical care. Call in advance and tell your health provider of any recent travel or recent contact with travelers.

    Effective Virus Inactivation And Removal By Steps Of Biotest Pharmaceuticals IGIV Production Process

    The virus validation of three steps of Biotest Pharmaceuticals IGIV production process is described here. The steps validated are precipitation and removal of fraction III of the cold ethanol fractionation process, solvent/detergent treatment and 35 nm virus filtration. Virus validation was performed considering combined worst case conditions. By these validated steps sufficient virus inactivation/removal is achieved, resulting in a virus safe product. Read more here.

    Control of Viral Infections and Diseases 
    Karen L. Goldenthal, Karen Midthun, and Kathryn C. Zoon.

    General Concepts

    Immunoprophylaxis against viral illnesses includes the use of vaccines or antibody-containing preparations to provide immune protection against a specific disease.

    Active Prophylaxis (Vaccines)
    Active immunization involves administering a virus preparation that stimulates the body's immune system to produce its own specific immunity. Viral vaccines now available for use include the following types: (1) attenuated live viruses; (2) killed viruses; (3) recombinant produced antigens. A vaccinee is a person who has been vaccinated.

    Immune Response to Vaccines: Vaccination evokes an antibody response and stimulates T lymphocytes. Vaccine effectiveness is assessed in terms of percentage of recipients protected and the duration and degree of protection. Most effective viral vaccines protect more than 90 percent of recipients and produce fairly durable immunity.

    Passive Prophylaxis
    Passive immunity is conferred by administering antibodies formed in another host. Human immunoglobulins remain a mainstay of passive prophylaxis (and occasionally therapy) for viral illnesses; they are usually used to protect individuals who have been exposed to a disease and cannot be protected by vaccination.

    Sanitation and Vector Control
    Many viral diseases are controlled by reducing exposure to the virus by (1) eliminating nonhuman reservoirs, (2) eliminating the vector, and (3) improving sanitation.

    Antiviral Chemotherapy
    There are three types of antiviral agents: (1) virucidal agents, which directly inactivate viruses, (2) antiviral agents, which inhibit viral replication, and (3) immunomodulators, which boost the host immune response.

    Virus-infected cells and cells induced with other agents, e.g., double-stranded polynucleotides, can secrete proteins called interferons, which protect normal cells from viral infection. Therapeutic administration of interferon alpha has proven effective for several human viral illnesses.

    Cytokines are molecules produced by cells which modify the biological responses of the same or other cells.

    Viral diseases range from trivial infections to plagues that alter the course of history. Because of the enormous variations in viruses and in their epidemiology and pathogenesis, there is no single, magic-bullet approach to control. Each virus presents its own set of problems. This chapter covers methods useful to various degrees in controlling selected viral diseases. The most spectacular progress so far has involved vaccines. Vector control and sanitation have contributed greatly. Also, a number of therapeutic antiviral agents are now available, including some for very serious infections such as human immunodeficiency virus type 1 (HIV-1) infection. In addition, interferon alpha is now available for the therapy of several viral diseases.

    Immunoprophylaxis against viral illnesses includes the use of vaccines or antibody-containing preparations to provide a susceptible individual with immunologic protection against a specific disease. Immunization against viral illnesses can be either active or passive. With active immunity, protection is achieved by stimulating the body's immune system to produce its own antibodies by immunization with a virus preparation. Passive immunity is conferred by administering antibodies formed in another host. For example, an antibody-containing gamma globulin preparation may protect a susceptible individual exposed to a viral illness.

    Active Prophylaxis (Vaccines)
    The viral vaccines currently approved for use in the United States are listed in TABLE 51-1. These products are of three types:

    (1) Attenuated live viral vaccines
    Most live vaccines contain viruses that have been attenuated by laboratory manipulation. These attenuated viruses can infect and replicate in the recipient and produce a protective immune response without causing disease. Live attenuated viral vaccines can often confer lifelong immunity after one immunization series. However, because live viruses can multiply in the body, there is always the possibility that they may revert to a more pathogenic form. Adequate laboratory and animal testing and extensive clinical studies must be performed to assess this possibility. In addition, new recombinant technologies facilitate direct alteration of viral genetic structure, thus permitting scientists to produce attenuated viruses in which the genetic regions likely to lead to pathogenic reversion are modified or deleted.

    (2) Killed (inactivated) viral vaccines
    Killed viral vaccines contain either whole virus particles, inactivated by chemical or physical means, or some component(s) of the virus. Completely inactivated viral vaccines cannot cause infection. However, they do not generally produce lifelong immunity following one immunization series; additional doses are usually required. In addition, because killed virus does not multiply in the host, the inoculum itself must provide a sufficiently large concentration of viral antigens to induce the desired immune response.

    (3) Recombinant-produced antigens
    Application of a recombinant DNA strategy to develop new vaccines is performed by identifying the specific component(s) that can elicit the production of protective antibodies, and then cloning and expressing the gene encoding that protein and assembly of a complex in some cases. This approach has made possible a safe and effective recombinant vaccine against hepatitis B virus, which has replaced the vaccine derived from the plasma of hepatitis B virus-infected individuals.

    Immune Response to Vaccines
    Vaccination evokes an antibody response which is, in turn, a measure of the effectiveness of the vaccine in stimulating B lymphocytes. Antiviral antibodies are classified as IgA, IgM, or IgG and can be measured by various techniques. Some antibody categories (IgA and IgM) are normally more abundant in respiratory and intestinal secretions; others (mainly IgG) are more abundant in the circulatory system.

    Vaccines also stimulate T lymphocytes, leading to cell-mediated responses that influence protection. Antibody assays are now routine laboratory procedures, but measuring cellular immunity in vitro usually requires the utilization of complex laboratory techniques. In general, despite the complexities of the immune system, resistance to the vaccine-preventable viral diseases often correlates well with the presence of circulating antiviral antibodies, which are easily measured.

    Effectiveness is a key concern with any vaccine. Here the standard for comparison is usually the immunity conferred by the natural disease; an example of an exception is rabies. Both epidemiologic and laboratory methods are used to generate comparative data. Vaccine-induced immunity can be defined by the percentage of recipients protected, the projected duration of protection, and the degree of protection. Most viral vaccines considered effective protect more than 90 percent of recipients, and the immunity produced appears to be fairly durable, lasting several years or more. However, vaccines usually do not induce an immunologic response entirely comparable to that seen in the natural disease. Immunity to viral diseases should not be thought of as absolute. Persons immune due to the natural infection, as well as, vaccinees, sometimes experience subclinical reinfection if exposed. Evaluating the protection conferred by a vaccine often involves measuring the frequency and extent to which subclinical reinfection can override vaccine-induced resistance.

    Often, upon revaccination or reinfection, a boost in IgG antibodies is observed with little or no detectable IgM response, suggesting prior exposure with antibody priming. Such anamnestic responses may be seen in individuals who lack detectable antibody prior to reexposure. Therefore, the absence of measurable antibody may not mean that an individual is unprotected.

    Immune responses to viral vaccines may be influenced by a number of factors related to the vaccine as well as to the host. As already discussed, the magnitude and duration of immunity differ significantly between live and killed vaccines. The immune response to vaccines can be enhanced by adding adjuvant substances such as aluminum salts (e.g., hepatitis B vaccine). The route of administration of a vaccine can also influence the immunogenicity of some vaccines. Also, maternal antibodies acquired transplacentally can interfere with responses to measles, mumps, and rubella (MMR) vaccine, as demonstrated by lower response rates when the vaccine is administered earlier than 15 months of age. In this case, it is thought that the antibodies interfere with the post-vaccination replication of these live vaccine viruses in the host.

    Vaccine Production
    Because viruses are obligate intracellular parasites, all viral vaccines contain substances derived from the cells or living tissues used in virus production. Technical advances have improved production methods. One can think of generations of vaccines: those prepared in the tissues of an inoculated animal are the first generation (e.g., smallpox vaccine from the skin of a calf), products from the inoculation of embryonated eggs are the second generation (e.g., inactivated influenza virus vaccine), and tissue culture-propagated vaccines are the third generation (e.g., poliomyelitis, measles, mumps, and rubella vaccines). The vaccine generation indicates the production methodology, sophistication, and relative purity. Third generation vaccines usually contain the least host protein and other extraneous constituents, but they have been the most difficult to produce. Advances in biotechnology, i.e., recombinant DNA-derived subunit vaccines, now serve as the cornerstone for a fourth generation of vaccines and have led to the development and licensure of a recombinant hepatitis B vaccine. In addition, exciting new technologies such as polynucleotide vaccines are now being tested in animal studies for several viral diseases.

    Developing New Vaccines
    The past success with developing highly effective viral vaccines has been considerable. To develop a new vaccine, researchers must first identify and then produce the virus (or virus components) in quantity under circumstances acceptable for vaccine preparation. Normally this means production of virus or virus components in cell cultures, embryonated eggs, or tissues of experimental animals or humans, or through nucleic acid recombinant technology. Finding an acceptable production system can be a problem, especially in developing inactivated viral vaccines, because a high concentration of antigen is needed. As already mentioned, production of specific viral proteins by recombinant DNA procedures is providing a solution to many of these problems. A final consideration is the clinical importance of the virus. Normally, it must cause a disease of some severity and there must be an identifiable at-risk target population before consideration is given to developing a vaccine.

    However, there are still important indications for which there is no effective vaccine. From a public health perspective an important example for which there is no effective vaccine available is human immunodeficiency virus type 1 (HIV-1). Some of the challenges for the development of an HIV-1 vaccine include the following: (1) the type of immune response required to prevent HIV-1 infection is unknown; (2) there is no animal model for AIDS caused by HIV-1; (3) there are multiple types or clades of HIV-1 which may require the development of a multivalent vaccine; (4) even within a clade, there is considerable viral antigen variation; (5) some successful traditional approaches to viral vaccines, such as live attenuated viruses, pose considerable potential safety risks to the vaccinee.

    Passive Prophylaxis
    The use of immunoglobulin preparations remains a mainstay of passive prophylaxis (and occasionally of therapy) for viral illnesses. Passive immunoprophylaxis is most often recommended in one of these situations: (1) when exposure has occurred, or is expected to occur very soon, and time does not allow for vaccination and the development of an adequate post-vaccination immune response; (2) when no effective vaccine exists; (3) when an underlying illness precludes a satisfactory response to vaccination. Although once derived exclusively from animal sources, most immunoglobulins are now manufactured from human sources. Table 51-2 lists the types of immunoglobulins approved for use in the United States.

    Standard immunoglobulin is produced by pooling plasma obtained from thousands of donors and contains antibodies to a number of common viruses. Specific immunoglobulins are produced from donors with high titers of antibodies to specific viruses, often selected following immunization with the relevant vaccine.

    Sanitation and Vector Control
    Several early approaches to virus control deserve recognition even though they are less dramatic than vaccination. One approach is the avoidance of viral exposure. This is an effective means of preventing the transmission of HIV-1, which is spread through sexual contact and exposure to blood of infected individuals. Blood bank testing, e.g., for hepatitis B surface antigen and for antibodies to HIV-1, HIV-2, HTLV-I, and hepatitis C, also avoids exposure by identifying and discarding blood units contaminated with these infectious agents.

    Control of nonhuman viral reservoirs is another early, worthwhile approach. Unfortunately, few opportunities exist for practical application. The most notable success was the control, and in some cases, the elimination of rabies in some countries through removal of stray dogs, quarantine of incoming pets, and vaccination of domestic animals.

    Another approach of enormous contemporary and historic importance is vector control. Transmission of viral disease by the bite of an arthropod vector was first demonstrated by Walter Reed and his associates, with their discovery that yellow fever was transmitted by mosquitoes. At the turn of the century, yellow fever was a disease of major consequence in the Americas and Africa. By immediately applying Reed's discovery, Gorgas mounted the anti-Aedes aegypti campaign in Havana that marked the beginning of the conquest of epidemic yellow fever. In dealing with the arthropod-borne diseases such as St. Louis encephalitis, any procedure that reduces vector populations or limits the access of the arthropod to humans has potential value. These procedures include draining swamps, applying insecticide, screening homes, and using insect repellant or protective clothing.

    The last of the older approaches is to improve sanitation. This method is applicable in a limited way to diseases whose epidemiology involves fecal-oral transmission. The well-known link between the discharge of raw sewage into tidal waters, contamination of shellfish, and type A hepatitis is an example of a situation readily reversible by improved sanitary practices.

    Antiviral Chemotherapy
    Antiviral chemotherapeutic agents can be divided into three categories: virucidal agents, antiviral agents, and immunomodulators. Virucidal agents directly inactivate intact viruses. Although some of these agents have clinical usefulness (e.g., topical treatment of warts with podophyllin, which destroys both virus and host tissues), most virucides have no demonstrated therapeutic value. Antiviral agents inhibit viral replication at the cellular level, interrupting one or more steps in the life cycle of the virus. These agents have a limited spectrum of activity and, because most of them also interrupt host cell function, they are toxic to various degrees. The emergence of drug resistant viruses may occur during clinical use that further limits the effectiveness of various antivirals. Immunomodulators such as interferons that alter the host immune responses to infection could, in principle, be protective, and several are under investigation.

    A number of antiviral agents with demonstrated effectiveness are now available (TABLE 51-3). These antiviral agents improve the clinical course of disease, but typically have important limitations especially as therapeutics for chronic or latent infections. For example, the four nucleoside analog drugs now available for the therapy of HIV-1 do not prevent the ultimate worsening of disease. The concept of a targeted approach is now practical since information concerning the structure and replication of viruses and the spatial configuration and function of their proteins is available. Such data may be useful in identifying specific target sites for antiviral agents.

    Interferons: Cytokines With Antiviral Activity
    Since the mid-1930s, scientists have recognized that under certain circumstances one virus can interfere with another. In 1957, Isaacs and Lindenman made a dramatic discovery that explained the mechanism of resistance. They found that virus-infected cells can elaborate a protein substance called interferon, which, when added to normal cells in culture, protects them from viral infection. Other microbial agents (such as rickettsiae and bacteria) and natural and synthetic polypeptides were later shown to induce interferon. There are three types of interferon: alpha, beta and gamma. Interferon alpha is produced by leukocytes, interferon beta is produced predominantly by fibroblasts and interferon gamma is produced by activated lymphocytes. Interferons tend to exhibit species specificity (mouse cell interferon protects mouse cells to a much greater extent than human cells) and are inhibitory to numerous viruses.

    For many years it was not possible to obtain sufficient quantities of interferons to conduct major studies. However, recombinant DNA technology and cell culture technology led to the production of adequate supplies of interferons and the subsequent conduct of extensive clinical trials. Although broadly antiviral in some animal models, interferon alpha has proven effective in a limited number of viral illnesses of humans, including chronic hepatitis B and C and refractory condylomata acuminata. In addition, interferons have been effective in the treatment of other diseases. For instance interferon alpha is effective for hairy cell leukemia and AIDS-related Kaposi's sarcoma in a selected group of individuals; interferon beta for relapsing-remitting multiple sclerosis; and interferon gamma for reducing the frequency and severity of serious infections associated with chronic granulomatous disease.

    Identifying New Effective Therapeutics
    The improved basic science knowledge base of viruses combined with the urgent need for improved therapeutics, especially for HIV-1, has given considerable impetus to the search for new approaches. Some approaches under investigation that may lead to future approved therapies are described here:

    Combination Therapy
    The use of multiple drugs with different mechanisms of action is being studied as a method of improving clinical effectiveness. Such combinations may offer advantages over monodrug therapy such as improved antiviral activity, preventing or delaying the development of drug resistance, and use of lower, less toxic doses. Combinations of various antiviral agents have been extensively studied for HIV. In addition, approaches investigated for HIV have included combining a cytokine with one or more antiviral agents. Combination therapy has been effective in the treatment of diseases caused by other infectious agents (e.g., Mycobacterium tuberculosis and Pseudomonas aeruginosa).

    Discovering New Drugs
    New drugs with novel mechanisms of action are being sought and developed. Some of these have displayed considerable antiviral activity in human clinical trials, e.g., protease inhibitors for HIV-1.

    Evaluating Available Drugs for New Indications
    Interleukin-2, a cytokine currently approved for treating renal cell carcinoma, has shown considerable immunomodulatory activity in some HIV-1 infected patients in early human studies.

    With Nano-Diamonds And Salt, Researchers Race To Design A Face Mask That Kills The Coronavirus

    The coronavirus pandemic has prompted an unprecedented surge in demand for surgical masks, which offer some protection against the transmission of disease. However, masks become contaminated themselves as they filter pathogens from the air. As a result, they risk spreading more disease. That’s a design flaw researchers are currently trying to fix. They're working to design a better mask—one that can kill viruses and bacteria, rather than just trap them.

    “Current masks don’t destroy the virus, that’s why they’ve been recommended for single use, but practically it is impossible to change the mask every few hours,” said Choi Hyo-jick, an assistant professor in the Department of Chemical and Materials Engineering at the University of Alberta. Choi has been working on a product that can provide an anti-viral coating to surgical masks to make them safer. The secret ingredient is salt. Read more here.

    The Coronavirus Isn't alive. That's Why It's So Hard To Kill

    The science behind what makes this coronavirus so sneaky, deadly and difficult to defeat. Viruses have spent billions of years perfecting the art of surviving without living — a frighteningly effective strategy that makes them a potent threat in today’s world.

    That’s especially true of the deadly new coronavirus that has brought global society to a screeching halt. It’s little more than a packet of genetic material surrounded by a spiky protein shell one-thousandth the width of an eyelash, and it leads such a zombielike existence that it’s barely considered a living organism. But as soon as it gets into a human airway, the virus hijacks our cells to create millions more versions of itself. Read more here.

    Top Ten Natural Anti-Viral Agents

    Winter is the time of year when we seem to be particularly vulnerable to all kinds of illnesses that are caused by viruses including colds, flu and cold sores. A virus is not to be confused with bacteria, which causes infection. Viruses are tiny bits of nucleic acids that contain information and use your body’s cells tor create more copies of themselves.

    There are very few treatments, allopathic or natural that can kill a virus outright, as usually a virus must run its course. However the list of natural remedies here come as close to stopping a virus in its tracks as Mother Nature can get.


    Silver has been utilized as a medicine since ancient times to treat scores of ailments, including the bubonic plague. Colloidal silver is a suspension of pure metallic silver in water, that is used to dramatically reduce the activity of the HIV virus in AIDS patients, slow down the ravages of the hepatitis C virus and combat other viruses in general. It works by interfering with the enzymes that allow a virus to utilize oxygen thus, in essence, suffocating it so it cannot do damage in the body.


    The common black elderberry (Sambucus nigra) has long been used to reduce the length and severity of flu symptoms and studies. Taking 60 ml a day for adults and 30 ml for children helps to facilitate a complete recovery, often in three days. Elderberry extract binds to the tiny spikes on a virus protein that are used to pierce and invade healthy cells and destroys them so that the virus is ineffective. Elderberry may also be effective against the herpes simplex virus and some HIV strains.


    The herb Echinacea (Echinacea purpurea) is supportive of the immune system and has a direct anti-viral action against colds and viral bronchitis. Preparations that include both the roots and the flowering tops are the most effective at helping the body resist the viruses.


    Garlic has been prized for its medicinal properties for thousands of years. The compounds allicin and alliion are responsible for this common plant’s reputation as a triple threat. Garlic is anti-viral, anti-bacterial and anti-fungal and it is especially effective against viruses if chewed raw.


    Green tea (Camellia sinensis) contains a group of flavonoids called catechins, which appear to inhibit viral infections by blocking the enzymes that allow it to reproduce. Green tea has been known to be effective in inhibiting HIV, herpes simples and the hepatitis B virus.


    Liquorice contains a substance called glycyrrhizin that reduces the replication of viruses and halts their ability to penetrate replicate inside healthy cells. It has been noted to be effective in the treatment of many viral illnesses including HIV strains and viral hepatitis.


    The leaves of Olive trees (Olea europea) contain a substances called elenoic acid and calcium elonate has been identified as a powerful inhibitor of a wide range of viruses in laboratory tests., including influenza, herpes, polio and coxsackie viruses. These substances block the production of enzymes that allow viruses to replicate.


    Pau d’arco (Tabebuia impetiginosa), also known as lapacho or ipe roxo, is an Amazon tree with healing inner bark that can treat colds, influenza, herpes and viral stomatis. It contains quinoids that inhibit virus replication by damaging the DNA and RNA inside the viral protein that would insert itself in a healthy human cell and replicate.


    St John’s Wort (Hypericum perforatum) is ore well-known for its ability to treat depression and neuralgia but it also has potent antiviral chemicals called hypercin and pseudohypericin that proactively fight off viruses that thrive by imitating existing cells through “cloaking”. These viruses that masquerade as human cells include Herpes, HIV and Hepatitis C.

    Understanding Emerging and Re-emerging Infectious Diseases

    The term "disease" refers to conditions that impair normal tissue function. For example, cystic fibrosis, atherosclerosis, and measles are all considered diseases. However, there are fundamentally different causes for each of these diseases. Cystic fibrosis (CF) is due to a specific genotype that results in impaired transport of chloride ions across cell membranes, leading to the production of abnormally thick mucus. Thus, CF is most accurately called a genetic or metabolic disease. Atherosclerosis, which can lead to heart attacks and strokes, may be considered a disease of aging, because it typically becomes a problem later in life after plaques of cholesterol have built up and partially blocked arteries. In contrast, measles is an infectious disease because it occurs when an individual contracts an outside agent, the measles virus. An infectious disease is a disease that is caused by the invasion of a host by agents whose activities harm the host's tissues (that is, they cause disease) and can be transmitted to other individuals (that is, they are infectious).

    Nature of Infectious Diseases 

    Microorganisms that are capable of causing disease are called pathogens. Although microorganisms that cause disease often receive the most attention, it is important to note that most microorganisms do not cause disease. In fact, many probably provide some protection against harmful microorganisms because they effectively compete with the harmful organisms for resources, preventing them from growing.

    A true pathogen is an infectious agent that causes disease in virtually any susceptible host. Opportunistic pathogens are potentially infectious agents that rarely cause disease in individuals with healthy immune systems. Diseases caused by opportunistic pathogens typically are found among groups such as the elderly (whose immune systems are failing), cancer patients receiving chemotherapy (which adversely affects the immune system), or people who have AIDS or are HIV-positive. An important clue to understanding the effect of HIV on the immune system was the observation of a rare type of pneumonia among young men caused by Pneumocystis carinii, an organism that causes disease only among the immunosuppressed.

    The terms "infection" and "disease" are not synonymous. An infection results when a pathogen invades and begins growing within a host. Disease results only if and when, as a consequence of the invasion and growth of a pathogen, tissue function is impaired. Our bodies have defense mechanisms to prevent infection and, should those mechanisms fail, to prevent disease after infection occurs. Some infectious agents are easily transmitted (that is, they are very contagious), but they are not very likely to cause disease (that is, they are not very virulent). The polio virus is an example: It probably infects most people who contact it, but only about 5 to 10 percent of those infected actually develop clinical disease. Other infectious agents are very virulent, but not terribly contagious. The terror surrounding Ebola hemorrhagic fever is based on the virulence of the virus (50 to 90 percent fatality rate among those infected); however, the virus itself is not transmitted easily by casual contact. The most worrisome infectious agents are those that are both very contagious and very virulent.

    In order to cause disease, pathogens must be able to enter the host body, adhere to specific host cells, invade and colonize host tissues, and inflict damage on those tissues. Entrance to the host typically occurs through natural orifices such as the mouth, eyes, or genital openings, or through wounds that breach the skin barrier to pathogens. Although some pathogens can grow at the initial entry site, most must invade areas of the body where they are not typically found. They do this by attaching to specific host cells. Some pathogens then multiply between host cells or within body fluids, while others such as viruses and some bacterial species enter the host cells and grow there. Although the growth of pathogens may be enough to cause tissue damage in some cases, damage is usually due to the production of toxins or destructive enzymes by the pathogen. For example, Corynebacterium diphtheriae, the bacteria that causes diphtheria, grows only on nasal and throat surfaces. However, the toxin it produces is distributed to other tissues by the circulatory system, damaging heart, liver, and nerve tissues. Streptococcus pyogenes, the infectious agent associated with several diseases including strepthroat and "flesh-eating disease," produces several enzymes that break down barriers between epithelial cells and remove fibrin clots, helping the bacteria invade tissues.


    Microbiologists have found viruses that infect all organisms, from plants and animals to fungi and bacteria. Viruses, however, are not organisms themselves because, apart from a host cell, they have no metabolism and cannot reproduce. A virus particle is composed of a viral genome of nucleic acid that is surrounded by a protein coat called a capsid. In addition, many viruses that infect animals are surrounded by an outer lipid envelope, which they acquire from the host cell membrane as they leave the cell. Unlike organisms, in which the genetic material is always double-stranded DNA, viral genomes may be double- or single-stranded DNA (a DNA virus), or double- or single-stranded RNA (an RNA virus).

    In the general process of infection and replication by a DNA virus, a viral particle first attaches to a specific host cell via protein receptors on its outer envelope, or capsid. The viral genome is then inserted into the host cell, where it uses host cell enzymes to replicate its DNA, transcribe the DNA to make messenger RNA, and translate the messenger RNA into viral proteins. The replicated DNA and viral proteins are then assembled into complete viral particles, and the new viruses are released from the host cell. In some cases, virus-derived enzymes destroy the host cell membranes, killing the cell and releasing the new virus particles. In other cases, new virus particles exit the cell by a budding process, weakening but not destroying the cell.

    In the case of some RNA viruses, the genetic material can be used directly as messenger RNA to produce viral proteins, including a special viral RNA polymerase that copies the RNA template to produce the genetic material for new viral particles. Other RNA viruses, called retroviruses, use a unique enzyme called reverse transcriptase to copy the RNA genome into DNA. This DNA then integrates itself into the host cell genome. These viruses frequently exhibit long latent periods in which their genomes are faithfully copied and distributed to progeny cells each time the cell divides. The human immunodeficiency virus (HIV), which causes AIDS, is a familiar example of a retrovirus.

    Just like other infectious agents, viruses cause disease by disrupting normal cell function. They do this in a variety of ways. Some viruses make repressor proteins that stop the synthesis of the host cell's proteins, RNA, and DNA. Viral activity may weaken cell membranes and lysosomal membranes, leading to cell autolysis. Some viral proteins are toxic to cells, and the body's immune defenses also may kill virus-infected cells.

    Viruses are classified using a variety of criteria, including shape, size, and type of genome. Among the DNA viruses are the herpes viruses that cause chicken pox, cold sores, and painful genital lesions, and the poxvirus that causes smallpox. Significant RNA viruses that cause human disease include rhinoviruses that cause most common colds; myxoviruses and paramyxoviruses that cause influenza, measles, and mumps; rotaviruses that cause gastroenteritis; and the retroviruses that cause AIDS and several types of cancer.

    Host Defenses Against Infectious Diseases 

    The human body has several general mechanisms for preventing infectious diseases. Some of these mechanisms are referred to as nonspecific defenses because they operate against a wide range of pathogens. Other mechanisms are referred to as specific defenses because they target particular pathogens and pathogen-infected cells.

    Nonspecific Mechanisms 

    Nonspecific mechanisms are the body's primary defense against disease. These mechanisms include anatomical barriers to invading pathogens, physiological deterrents to pathogens, and the presence of normal flora. An example of an anatomical barrier is the nasal opening to the respiratory system. This natural opening is a long, convoluted passage covered by mucous membranes that trap airborne particles and prevent most of them from reaching the lungs. Other anatomical barriers are the skull and vertebral column, which protect the central nervous system— few pathogens are able to penetrate bone. The skin also is a major anatomical barrier to microorganisms. The surface layer of dead, hardened cells is relatively dry, and skin secretions make the surface somewhat acidic. When sweat evaporates, salt is left behind on the skin. All of these conditions (low moisture, low pH, and high salinity) prevent most microorganisms from growing and multiplying on the skin. The major medical challenge in treating burn patients is preventing and treating infections that result because of the absence of skin that ordinarily would prevent invasion of microorganisms.

    Natural openings also are protected by a variety of physiological deterrents. For example, tears continually flush debris from the eyes. Vaginal secretions are acidic, a hostile environment that discourages the growth of many pathogens. The eye, mouth, and nasal openings are protected by tears, saliva, or nasal secretions that contain lysozyme, an enzyme that breaks down bacterial cell walls. Blood, sweat, and some tissue fluids contain lysozyme as well.

    In addition to lysozyme, the blood has many elements that defend the body from disease-causing organisms. The white blood cells include several types of phagocytic cells that detect, track, engulf, and kill invading bacteria and viruses, as well as infected host cells and other debris. These phagocytic cells are part of the nonspecific immune sys tem. Blood plasma also includes clotting factors that initiate a clot at the injury site, preventing pathogens from invading the body further. Finally, the complement proteins in the blood participate in a cascade of molecular events that result in inflammation, the release of molecules that stimulate phagocytic cells, and the formation of a complex of proteins that binds to the surface of bacterial or infected host cells and lyses those cells.

    The inflammatory response is another nonspecific defense mechanism that helps prevent infectious agents from spreading in the body. Inflammation involves swelling, reddening, elevated temperature, and pain. Unfortunately, inflammation itself frequently causes tissue damage and, in severe cases, even death.

    Finally, the protective role of the "normal flora" of microorganisms present on and in the body should not be overlooked. These organisms survive and grow on the skin and in the mouth, gastrointestinal tract, and other areas of the body, but do not cause disease because their growth is kept under control by the host's defense mechanisms and by the presence of other microorganisms. These organisms protect the host by successfully competing with disease-causing organisms, preventing the latter from invading host tissues. When the growth of the normal flora is suppressed (for example, due to antibiotic treatment), other "opportunistic" agents that normally do not grow in or on the body may be able to infect and cause disease.

    Treatment Of Viral Diseases 

    In general, drugs that effectively inhibit viral infections are highly toxic to host cells because viruses use the host's metabolic enzymes in their reproduction. For this reason, most illnesses due to viruses are treated symptomatically until the host's immune system controls and eliminates the pathogen (or the host dies). Antiviral drugs that are used typically target virus-specific enzymes involved in viral nucleic acid synthesis. One of the most familiar of these drugs is acyclovir, which is used to treat outbreaks of genital herpes. Amantadine is an antiviral drug sometimes used to prevent or moderate influenza among those at high risk of severe illness from the disease. In addition to antiviral drugs that inhibit the replication of the HIV genome (such as AZT), AIDS patients today are also prescribed proteases that interfere with the packaging of the HIV genome into virus particles.

    Human Viruses Harbor Ancient Kill Code | HIV, Hepatitis B And Other Viruses May Kill Host Cells By Activating Code
    December 11, 2019 | By Marla Paul

    Deep in the genetic material of pathogenic human viruses such as HIV-1, hepatitis B and assorted herpes viruses, lies an ancient kill code that is at least 800 million years old, reports new Northwestern Medicine research.

    “We believe these viruses can kill their host cells using the kill code,” said lead study author Marcus Peter, a professor of medicine at Northwestern University Feinberg School of Medicine. “Understanding how viruses affect cell survival, particularly, how they kill their host cells, could provide a novel way to attack virus-infected cells and eliminate them.”

    The findings may open the way to eliminate all HIV-1 infected cells to cure patients of AIDS, Peter said. “This might be feasible because the virus only infects a very small percentage of its host's immune cells,” he said.

    Peter is currently studying whether certain viruses -- specifically HIV-1 -- actually use the code sequences to kill.

    The study was published in iScience Dec. 11, 2019.

    In research published in 2018 in Nature Communications, Peter and his team discovered sequences in the human genome that, when converted into small double-stranded RNA molecules, trigger what they believe to be an ancient kill switch in cells to prevent cancer.

    “Human viruses must have coevolved with a mechanism that old,” said Peter, the Tom D. Spies Professor of Cancer Metabolism and leader of the translational research in solid tumors program at the Robert H. Lurie Comprehensive Cancer Center of Northwestern University. “Viruses during evolution act like mirrors of our cellular functions.”

    RNA is best known for its role in facilitating the translation of genes into proteins which regulate all cellular functions. However, there are many very small RNAs (microRNAs) that do not code for proteins and rather suppress gene expression.

    In his new paper, Peter and colleagues show the kill code can be found across all microRNAs in 17 human disease-causing viruses. These new data suggest many of these viruses can kill cells by activating the code.

    A screen in this new work included microRNAs from viruses that cause disease by killing cells. The scientists first showed that a viral microRNA with known anticancer activity in human Kaposi's sarcoma-associated herpes virus uses the kill code. Then toxic microRNAs also were found in HIV-1, which kills certain types of immune cells, and in the hepatitis B virus that causes disease by killing liver cells.

    “This provides a new view on how viruses cause tissue destruction and may open a path to develop novel antiviral therapies,” said first author Andrea Murmann, research associate professor of medicine at Feinberg.

    Currently, 38 million people worldwide are infected with the AIDS virus HIV-1 with no cure in sight. An even greater number of patients -- 250 million people worldwide -- suffer from hepatitis B.

    “Understanding how viruses affect cell survival, particularly how they kill their host cells, could provide a novel way to attack virus-infected cells and eliminate these cells without affecting uninfected tissues,” Peter said.

    The discovery that microRNAs of many human disease-causing viruses contain the kill code validates the concept of the kill code itself.

    “In my view it confirms that we are dealing with an ancient mechanism that emerged during evolution and got hijacked by viruses,” Peter said.

    Next, Peter’s lab will test whether HIV-infected T cells (a type of immune cell) can be killed by treating them with artificial microRNAs that carry a strong kill code without killing uninfected immune cells. If scientists observe a selective death of HIV-infected cells, then this could be a viable strategy to attack only HIV-infected cells after driving the virus out of hiding in the genome of the infected cells.

    Other Northwestern authors include Elizabeth T. Bartom, Matthew J. Schipma and Jacob Vilker.

    The research was supported by grant R35CA197450 from the National Cancer Institute of the National Institutes of Health.

    Researchers Develop a System to Kill Viruses Found in Human Cells
    A team of researchers developed a system to kill RNA-based viruses such as Ebola in human cells.
    By Donna Fuscaldo | October 10, 2019

    Some of the most common and deadly viruses to humans are RNA based and have little in the way of FDA approved treatments.

    To address that, a team of researchers led by the Broad Institute of MIT and Harvard developed an antiviral agent that can find and destroy RNA-based viruses hiding out in human cells.

    There's a lack of drugs to kill these RNA viruses 

    In a research report, which was published in journal Molecular Cell, the researchers co-led by senior author Pardis Sabeti, a member at the Broad Institute and a professor at Harvard University, Catherine Freije, a graduate student at Harvard University, and Cameron Myhrvold, a Graduate School of Arts and Sciences postdoc, were able to turn a CRISPR RNA cutting enzyme into an agent that can destroy the viruses including Ebola, Zika and flu.

    The efforts on the part of the researchers comes at a time when drugs aren't doing enough to kill these infections. According to the researchers, during the past 50 years, 90 clinically approved antiviral drugs have been developed but they only treat nine diseases. The drugs don't reflect the fact that viral pathogens can evolve and become resistant to current treatments. The researchers noted that only 16 viruses have vaccines that are approved by the FDA.

    CARVER systems could fight a variety of viruses

    The researchers had previously made the Cas13 enzyme into a tool to cut and edit RNA and to detect viruses and bacteria in human cells. Now they are using Cas13 or any CRISPR system to act as an antiviral in human cells. The researchers combined the capabilities of Cas13 into one system that in the future could diagnose and treat these infections. The system is Called CARVER.

    “Human viral pathogens are extremely diverse and constantly adapting to their environment, even within a single species of virus, which underscores both the challenge and need for flexible antiviral platforms,” said Sabeti, who is also a Howard Hughes Medical Institute investigator said in a press release highlighting the research. “Our work establishes CARVER as a powerful and rapidly programmable diagnostic and antiviral technology for a wide variety of these viruses.”

    Researchers' tool reduced the viral RNA cells 40 fold

    To test the effectiveness of its CARVER system, the researchers tested it in human cells that had lymphocytic choriomeningitis virus (LCMV), influenza A virus (IAV), and vesicular stomatitis virus (VSV). Twenty-four hours after introducing the Cas13 gene and a guide RNA into the cells, the researchers exposed the cells to the virus. After another 24 hours, the Cas13 enzymes reduced the level of viral RNA in the cells by as much as 40 times.

    “We envision Cas13 as a research tool to explore many aspects of viral biology in human cells,” said Freije in the same press release. “It could also potentially be a clinical tool, where these systems could be used to diagnose a sample, treat a viral infection, and measure the effectiveness of the treatment — all with the ability to adapt CARVER quickly to deal with new or drug-resistant viruses as they emerge.”

    How Known Drugs Could Be Applied To The Current Coronavirus Outbreak
    Victoria Corless | February 6, 2020 | Advanced Science News

    Researchers around the world are tirelessly working to provide treatment options for the newly emerged 2019 novel coronavirus (2019-nCoV), an infectious virus that is thought to have originated in a Wuhan seafood market in December of last year. As the number of infected people continues to rise — as of February 4, 2020, the number surpassed 20 000 people, with current numbers estimated at 20 530 — and with the current trajectory of the outbreak unknown, understanding the virus’ biology, as well as public health and medicinal measures, will be needed to contain the spread and optimize patient care.

    The first genome sequence of 2019-nCoV was made public in early January, which has led to diagnostic tests for the virus, as well as enhanced knowledge regarding its biology and evolution. And while efforts are being spent toward developing a vaccine, researchers from Texas A&M University suggest that we could learn from the past to produce urgently needed treatment options for those already affected.

    The team was led by Wenshe Liu, and in their study — published in ChemBioChem — the researchers suggest four potential drug candidates that could be used to treat patients currently suffering from the virus. “Although it is essential to develop vaccines, small molecules, and biological therapeutics to specifically target the 2019-nCoV, it is unlikely that any effort made at the moment will benefit patients in the current outbreak,” said the authors.

    An efficient approach to drug discovery is to test whether existing therapeutics for similar viruses are effective in treating current viral infections.

    “2019-nCoV shares 82% sequence identity with severe acute respiratory syndrome-related coronavirus (SARS-CoV),” they stated, “and more than 90% sequence identity in several essential enzymes. What we have learned from several medicinal chemistry studies about SARS-CoV and the Middle East Respiratory Syndrome (MERS-CoV) may be directly used in helping us treat the 2019-nCoV.”

    Drugs such as ribavirin, interferon, lopinavir-ritonavir, and corticosteroids, have been used previously to treat SARS or MERS, and may have potential in improving patient outcomes during this current outbreak.

    Similar to the SARS, the current coronavirus, 2019-nCoV, contains a large “spike protein”, which it uses to bind to host cells and then gain entry through the cell’s membrane. The receptor these viruses target is called angiotensin-converting enzyme 2 (ACE2). Vaccines were developed for SARS which specifically target the spike protein and ACE2 receptor, and while amino acid sequences of spike proteins in 2019-nCoV and SARS do show some overlap, mutations in the current virus might lower the efficacy of previously developed therapeutics. However, similar ideas may be applied in developing 2019-nCoV vaccines.

    “Alternative approaches are to directly use the 2019-nCoV [receptor binding domain] in combination with immunity-promoting agents to trigger the body to develop antibodies for neutralizing the virus … Before any potent therapeutics to neutralize the 2019-nCoV-[ACE2 receptor] interaction are available, a possible quick solution to block this interaction is to use [peptides derived from the] 2019-nCoV receptor binding domain and their combination cocktails.”

    Once inside the cell, 2019-nCoV attaches to the host cell’s ribosome — a cell’s protein factory — where it overrides the cell’s machinery to produce two polyproteins. RNA viruses in many families (including the coronavirus family) express their genomes using the synthesis and subsequent cleavage of precursor polyproteins within a host cell. After the coronavirus’ polyproteins are produced, two enzymes — specifically, coronavirus main proteinase (3CLpro) and the papain-like protease (PLpro) — are known to participate in processing the polyproteins into smaller components used for producing new viruses. In addition, in order to replicate the RNA genome, the CoV encodes an RNA-dependent RNA polymerase (RdRp), which is a replicase or an enzyme that catalyses the synthesis of a complementary RNA molecule using template.

    Therapeutics currently targeting the previously mentioned spike protein, RdRp, 3CLpro, and PLpro enzymes are possible treatment options for 2019-nCoV, according to the authors of the study. The team therefore proposes four known potential drug candidates, which were previously used to treat SARS. These include an ACE2-based peptide; the antiviral drug remdesivir; the 3CLpro inhibitor, 3CLpro-1; and a novel vinylsulfone protease inhibitor.

    “Since remdesivir is a drug undergoing a clinical trial, the authority in China may negotiate with Gilead in possible use of this drug for patients suffering with the2019-nCoV,” say the authors.

    Given what we have learned from similar outbreaks, it is hoped that application of current therapeutics will not only aid in alleviating the suffering of those currently affected, but will also help in the development of broad spectrum anti-coronaviral agents for future epidemics.

    Virus Disinfectant Efficacy Testing Information From Microchem Laboratory 

    Virucidal Efficacy Testing Introduction

    In the United States, virucidal disinfectants used on environmental surfaces are regulated by the Environmental Protection Agency (EPA) under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). The EPA regulates disinfectants and sanitizers as pesticides, often referring to them as "antimicrobial pesticides." Before a disinfectant can be sold in the U.S. it must first be registered with the EPA, as well as with all 50 states. Currently the U.S. EPA does not recognize "virucidal sanitizers" - all virucides must meet disinfectant-grade efficacy guidelines.

    To register a virucidal disinfectant, companies must submit chemical characterization, safety, and efficacy data to the EPA, as well as pay registration fees. Efficacy data should be generated in compliance with Good Laboratory Practice Regulations (GLP). Test methods used should be taken from the Series 810 guidance, and companies should consult the EPA's Pesticide Registration Manual.

    Disinfectant Testing Basics:

    The EPA currently only recognizes "hard surface carrier" methods for substantiation of virucidal efficacy claims. These methods consist of a non-porous carrier (typically glass) being inoculated with the selected virus, dried, and then treated with the disinfectant. Virucidal hard surface carrier methods are quantitative, meaning that percent and log reductions are calculated by determining the TCID50 (50% Tissue Culture Infective Dose) per carrier before and after treatment with the disinfectant. The disinfectant must demonstrate complete inactivation of the virus down to the limit of detection of the assay, or (if cytotoxicity is observed) a ≥ 3.00 log10 reduction (99.9%).

    Observation of Results: 
    Virus testing is unique within the laboratory because the presence of viruses before and after product treatment is not determined by observing growth of virus but rather by observing the damage caused by infection to mammalian host cells. When virologists analyze individual sets of cells after a study, they use a microscope to look for where healthy cell layers become damaged. This damage is known as the cytopathic effects (CPE) of infection. The quantity and quality of CPE is used to calculate the amount of virus present.

    CPE is typically observed as changes to cell appearance and monolayer (the layer host cells form when they attach to a flask or tray) disruptions. CPE can vary depending on the virus and host cell line used. Some instances of CPE are distinct, consisting of severe monolayer disruption and cell rounding. Some CPE can be subtle, consisting of gradual enlargement of host cells that is only recognizable when compared to a negative control. In cases where CPE is difficult to distinguish, special confirmatory assays are used to verify the results of the assay. Some more common confirmatory assays include Hemagglutination Assays (HA) and immunofluorescent staining (IF).

    Study Preparation and Timeline:

    From the laboratory's perspective, a significant amount of work and time is required to grow and maintain the sterile cell cultures that are needed to propagate and detect viruses in antimicrobial efficacy studies. From our customer's point of view, the cell culture requirement means that extra time must be given to the laboratory to prepare for and execute the study. Most studies take 1-2 weeks to complete, though some can take 3-4 weeks. The behind-the-scenes cell culture work and extraordinary expertise necessary to conduct virological assays also means that virological studies are more expensive than their related bacteriological assays.

    Study Conduct and Parameters:

    There are two main viral morphologies - enveloped and non-enveloped. Non-enveloped viruses consist of genetic material surrounded by a hard protein coat. Enveloped viruses have an additional lipid layer encompassing their protein coat. The limited sensitivity of non-enveloped viral components means that these viruses can persist in an infectious state even when exposed to harsh environmental conditions - including exposure to UV or relatively high temperatures. When it comes to testing, this means that one can translate almost any bacteriological study into a non-enveloped viral assay without changing too many parameters.

    Enveloped viruses are another story. Their delicate lipid envelopes leave them vulnerable to environmental factors like osmotic pressure, low humidity, and high temperatures. When working with enveloped viruses, certain parameters (like contact times and contact temperatures) and even general study methods may need to be modified to accommodate the unique demands of these microbes.


    • Adenovirus 1
    • Adenovirus 2
    • Bovine Viral Diarrhea Virus (US EPA-Approved Hepatitis C Surrogate)
    • Bovine Rotavirus
    • Canine Distemper Virus
    • Canine Parainfluenza Virus
    • Canine parvovirus
    • Coronavirus (human)
    • Coxsackievirus B3
    • Coxsackievirus B6
    • Echovirus 11
    • Enterovirus 68
    • Enterovirus 71
    • Epizootic Hemorrhagic Disease Virus
    • Equine Herpesvirus 1
    • Feline Calicivirus (US EPA-Approved Norovirus Surrogate)
    • Human herpesvirus 1 (HSV1)
    • Human herpesvirus 2 (HSV2)
    • Human herpesvirus 5 (Cytomegalovirus)
    • Hepatitis A virus
    • Influenza A virus, H1N1 (human)
    • Influenza A virus, H1N1 (swine)
    • Influenza B virus
    • Measles virus
    • Minute Virus of Mice
    • MS2 Bacteriophage (Viral Screening Tool)
    • Poliovirus 1
    • Respiratory Syncytial virus (RSV)
    • Rhinovirus
    • Rotavirus (Group A)
    • Vesicular Stomatitis Virus
    • Zika Virus

    Read more here.