There are two main types of hand sanitizers: alcohol-based and alcohol-free. Alcohol-based hand sanitizers contain varying amounts and types of alcohol, often between 60 percent and 95 percent and usually isopropyl alcohol, ethanol (ethyl alcohol) or n-propanol. Alcohol is known to be able to kill most germs. Alcohol-free hand sanitizers contain something called quarternary ammonium compounds (usually benzalkonium chloride) instead of alcohol. These can reduce microbes but are less effective than alcohol. Not only are alcohol-based hand sanitizers found to  be effective at killing many types of bacteria, including MRSA and E coli, they’re also effective against many viruses, including the influenza A virus, rhinovirus, hepatitis A virus, HIV, and Middle East respiratory syndrome coronavirus (MERS-CoV). According to the CDC, hand sanitizer is not as effective at killing germs as washing your hands with soap and water. The CDC says that washing your hands is a better tactic for removing certain viruses and bacteria, such as Cryptosporidium (causes diarrhea) and norovirus (stomach bugs).

Part of the reason that hand sanitizer isn’t as effective as washing your hands is that people often wipe their hands before the hand sanitizer dries completely. Also, if your hands are dirty or greasy, hand sanitizers may not work because they can’t penetrate dirt and grease like soap can. The World Health Organization recommends using hand sanitizer only as an alternative when you don’t have access to soap and water. Like the CDC and WHO, the National Institutes of Health also recommends washing your hands whenever possible. The US National Library of Medicine has a helpful topic page where you can find everything from quick facts to in-depth scientific studies on hand-washing.

Are Sanitizers only effective for Bacteria Not For Viruses
Iqra Rehman
Iqra Rehman

ARE SANITIZERS EFFECTIVE ONLY FOR BACTERIA NOT FOR VIRUSES

Coronavirus COVID-19 is here, and to put it scientifically, people are shitting their panties over it. People are buying masks that won’t protect them. They’re buying doomsday-survival gear they (very likely) won’t need. And, if they’re lucky enough to find it, they’re buying hand sanitizer in bulk — which in most cases, they don’t really need, either.

In recent weeks, as the death toll has climbed and the panic surrounding coronavirus has mounted, hand sanitizer has been increasingly difficult to find, with stores selling out of Purell and other sanitizer brands. On Amazon, third-party sellers have capitalized on the fear by selling hand sanitizer at an incredibly marked-up price, with packs of four bottles costing dozens of times the original amount. While a bottle of hand sanitizer typically costs about $2.50, on Amazon one reseller is selling two-packs of 8-oz. bottles of Purell for $79.99. And while Amazon has promised to actively monitor the situation and remove third-party vendors selling hand sanitizer at an outrageous cost, as of Thursday morning such listings were a simple search away.

For those of us who either can’t find hand sanitizer or can’t afford the mind-boggling markups, this is pretty terrifying — and for those of us with health-related anxiety, the hand sanitizer shortage can feel literally like the difference between life and death. It has even sparked a small subgenre of online content targeted at the coronavirus-anxious among us, with e-commerce articles hawking the top brands of hand sanitizer (none of which are actually available, which is helpful) and recipes for how to make your own. But if soap and water are not available, using a hand sanitizer with at least 60% alcohol can help you avoid getting sick and spreading germs to others. The guidance for effective hand washing and use of hand sanitizer in community settings was developed based on data from a number of studies.

How does hand sanitizer work?

There are two main types of hand sanitizers: alcohol-based and alcohol-free. Alcohol-based hand sanitizers contain varying amounts and types of alcohol, often between 60 percent and 95 percent and usually isopropyl alcohol, ethanol (ethyl alcohol) or n-propanol. Alcohol is known to be able to kill most germs. Alcohol-free hand sanitizers contain something called quarternary ammonium compounds (usually benzalkonium chloride) instead of alcohol. These can reduce microbes but are less effective than alcohol. Not only are alcohol-based hand sanitizers found to  be effective at killing many types of bacteria, including MRSA and E coli, they’re also effective against many viruses, including the influenza A virus, rhinovirus, hepatitis A virus, HIV, and Middle East respiratory syndrome coronavirus (MERS-CoV). According to the CDC, hand sanitizer is not as effective at killing germs as washing your hands with soap and water. The CDC says that washing your hands is a better tactic for removing certain viruses and bacteria, such as Cryptosporidium (causes diarrhea) and norovirus (stomach bugs).

Part of the reason that hand sanitizer isn’t as effective as washing your hands is that people often wipe their hands before the hand sanitizer dries completely. Also, if your hands are dirty or greasy, hand sanitizers may not work because they can’t penetrate dirt and grease like soap can. The World Health Organization recommends using hand sanitizer only as an alternative when you don’t have access to soap and water. Like the CDC and WHO, the National Institutes of Health also recommends washing your hands whenever possible. The US National Library of Medicine has a helpful topic page where you can find everything from quick facts to in-depth scientific studies on hand-washing.

There are two main types of hand sanitizers

Generally speaking, is hand sanitizer effective at killing germs?

Although popular hand sanitizer brands tout their effectiveness at killing, say, 99.9% of germs, up until fairly recently there was a vibrant debate in public-health spaces about whether hand sanitizer was even effective at fighting disease-causing bacteria to begin with. In 2016, the FDA requested that hand sanitizer brands prove that their products actually reduce bacteria as claimed and that they are harmless with prolonged use over time, with some data finding that certain antiseptic ingredients were present in users’ blood and urine for longer than previously thought. Scott says that he was initially “skeptical” of the value of hand sanitizers due to fire incidents and slip-and-fall accidents involving alcohol-based sanitizers in schools and hospitals. Over time, the conversation evolved from questioning whether alcohol-based hand sanitizers were safe to whether they were as effective as manufacturers claimed. And this is still something of an open question, at least according to the FDA, which, as recently as this year, sent a warning letter to Purell parent company GoJo telling it to stop making what they viewed as unfounded claims on its website, such as that Purell “may be effective against viruses such as the Ebola virus, norovirus, and influenza.” Overall, however, the consensus is that hand sanitizer products are generally considered not only safe, but “the evidence is fairly strong” that they are also effective against certain types of microorganisms. “I wouldn’t say I’m a convert, necessarily, but I’ve become convinced of the value as part of the bug-fighting kit,” in part due to their ease of use when soap and water are unavailable, says Scott. And one of those types of microorganisms it is likely effective against is COVID-19, which, as a member of the coronavirus, is membrane-enclosed.

Effect of alcohol base sanitizer;

The antimicrobial effectiveness of short-chain alcohols, mainly ethanol, against fungus and yeast has been well documented in the literature. In general, the most effective ethanol concentration range has been reported to be greater than 50%, acting in 1 minute. However, no data are available on the efficacy of alcohols at contact times of less than 1 minute or on alcohol-based sanitizers.  Regarding the antiviral activity of alcohols, it is well established that alcohols are effective against lipophilic, enveloped viruses. The data suggest that alcohols inactivate enveloped viruses more easily than “naked” viruses; however, there is no general agreement in the literature on the activity of alcohols against naked viruses. The results published to date suggest that alcohol is effective, but that the antiviral efficacy depends on the specific virus. Using tire finger pad method, recently found that the level of reduction of several naked viruses by an alcohol-based sanitizer was statistically significantly higher than that seen with a water control. To assess the antifungal and antiviral activity of an alcohol-based sanitizer, we conducted in vitro time exposure kill evaluations of PURELL Instant Hand Sanitizer (GOJO Industries, Inc., Akron, OH), which contains 62% ethanol and emollients. Fifteen- and 30-second exposures were used for the fungal species and 30-second exposures for the viruses. The 15- and 30-second exposures kill studies were performed using selected challenge fungi and viruses. The challenge inoculum was introduced to the test product at time 0; a portion of the sample was removed and placed in neutralizing media at the appropriate time (15 or 30 seconds). Standard plate-counting techniques were used to enumerate viable challenge microorganisms. The efficacy of the alcohol-based sanitizer against 7 fungal species is detailed in Table 1. It is apparent from Table 1 that the alcohol-based sanitizer was highly effective in 15 seconds against all of the fungal species investigated. The efficacy of the alcohol based sanitizer against viruses in 30- second exposure kill evaluations is detailed in Table 2. It is apparent that the alcohol-based sanitizer is effective against viruses in 30 seconds; however, the data show considerable variation, depending on the viral species.

The World Health Organization recommends using hand sanitizer only as an alternative when you don't have access to soap and water. Like the CDC and WHO, the National Institutes of Health also recommends washing your hands whenever possible. The US National Library of Medicine has a helpful topic page where you can find everything from quick facts to in-depth scientific studies on hand-washing.

There are different experiment had done in different time that show the activity of hand sanitizer; here some are given below,

Objectives: To analyze the biofilm-forming potential of clinical isolates of Staphylococcus aureus and Pseudomonas aeruginosa, and to assess antimicrobial activity of commonly used sanitizers in hospital and laboratory settings.

Method: The study was conducted at Aga Khan University Karachi from August 2016 to January 2017

The biofilm-forming potential of Staphylococcus aureus and Pseudomonas aeruginosa clinical isolates were evaluated qualitatively using air-liquid interface tube method, and air-liquid interface cover slip assay. The antimicrobial activity of commonly-used hand-washes and sanitizers were assessed using agar well diffusion method, while the anti-biofilm activity of the hand-washes and sanitizers was qualitatively assessed using air-liquid interface cover slip assay.

Results: Of the eight hand-washes and sanitizers, 2(25%) showed antimicrobial activity against both Staphylococcus aureus and Pseudomonas aeruginosa, while 2(25%) exhibited antimicrobial activity against either S. aureus or P. aeruginosa. Also, 4 (50%) of them showed no inhibitory activity against S. aureus and P. aeruginosa.

Conclusion: The findings shall have important consequences with regards to infection control in hospital and laboratory settings.

Objective. Good hand hygiene may reduce the spread of infections in families with children who are in out-of-home child care. Alcohol-based hand sanitizers rapidly kill viruses that are commonly associated with respiratory and gastrointestinal (GI) infections. The objective of this study was to determine whether a multifactorial campaign centered on increasing alcohol based hand sanitizer use and hand-hygiene education reduces illness transmission in the home.

Methods. A cluster randomized, controlled trial was conducted of homes of 292 families with children who were enrolled in out-of-home child care in 26 child care centers. Eligible families had >1 child who was 6 months to 5 years of age and in child care for >10 hours/week. Intervention families received a supply of hand sanitizer and biweekly hand-hygiene educational materials for 5 months; control families received only materials promoting good nutrition. Primary caregivers were phoned biweekly and reported respiratory and GI illnesses in family members. Respiratory and GI-illness–transmission rates (measured as secondary illnesses per susceptible person-month) were compared between groups, adjusting for demographic variables, hand-hygiene practices, and previous experience using hand sanitizers.

Results. Baseline demographics were similar in the 2 groups. A total of 1802 respiratory illnesses occurred during the study; 443 (25%) were secondary illnesses. A total of 252 GI illnesses occurred during the study; 28 (11%) were secondary illnesses. The secondary GI-illness rate was significantly lower in intervention families compared with control families (incidence rate ratio [IRR]: 0.41; 95% confidence interval [CI]: 0.19–0.90). The overall rate of secondary respiratory illness was not significantly different between groups (IRR: 0.97; 95% CI: 0.72-1.30).

However, families with higher sanitizer usage had a marginally lower secondary respiratory illness rate than those with less usage.

Scott says that he was initially “skeptical” of the value of hand sanitizers due to fire incidents

Hands are the prime means of transmission of microbes and the subsequent cause of nosocomial infections. To overcome the negative effect of microbial burden in health care settings, hand sanitizers are recommended for hand disinfection. Keeping this view, the present study was designed to demonstrate the antibacterial activity of fifteen hand sanitizers available in the market against the standard bacterial isolates (Staphylococcus aureus, Escherichia coli, Staphylococcus epidermidis and Pseudomonas aeruginosa) by using Kirby Bauer disc diffusion method. Their efficacy was checked at two concentrations (100% and 50%). Among the fifteen sanitizers tested, three of them Biotol=75%, Antibacterial hand gel=75% and Hiclean=62.5% were found to be the most effective. Other sanitizers such as Purell, Enliven, Lifebuoy, Rivaj were seen in the efficacy range of 12.5%-25% while no activity (0%) was observed in antiseptics Carex, Safeguard, Blue+King, Dial, Dettol, Cool and cool, Infectiguard and Newlife against all the tested bacterial isolates. Our study concluded that sanitizer Biotol, Antibacterial hand gel and Hiclean exhibited maximum efficacy at both concentrations and thus fulfilled the claim of their manufacturer as germicidal.

Do you need hand sanitizer to effectively fight COVID-19?

Per the Centers for Disease Control and Prevention, the most effective way of fighting coronavirus is using soap and water to wash your hands, and/or alcohol-based hand sanitizer. Specifically, it says: “Wash your hands often with soap and water for at least 20 seconds, especially after going to the bathroom; before eating; and after blowing your nose, coughing, or sneezing. If soap and water are not readily available, use an alcohol-based hand sanitizer with at least 60% alcohol.” But that “if” is pretty important here, says Dr. Christi Wojewoda, director of clinical microbiology at the University of Vermont Medical Center. “It doesn’t hurt to be cleaning your hands with hand sanitizer, but I don’t think that’s the most-required step” in fighting coronavirus, she says. Of the methods recommended by the CDC, “I would say washing your hands is number one; two is being very cognizant about touching your face; and three is using hand sanitizer.” Wojewoda stresses that cleaning your hands with soap and water (and hand sanitizer, if you aren’t able to wash your hands the traditional way) before you touch your face is crucial here. That’s because, as far as we know, simply touching a surface with a high burden (microbiologist-speak for “infected with a shit ton of”) the virus is not enough to get you sick. It has to be transmitted via the mucus membranes of your face, making avoiding touching your mouth, eyes, and nose an extremely important preventive measure.

Scott agrees that hand sanitizer is not as crucial in preventing coronavirus as many media outlets have claimed. “Even though we know alcohol kills the virus, it’s still more effective to wash your hands,” he says, citing previous data regarding the efficacy of soap and water in fighting viruses, like influenza, versus hand sanitizer. “That’s still the gold standard here.” He also stresses that washing your hands with soap and water before touching your face is key. “If I had to put in a contact lens I wouldn’t feel confident just having used hand sanitizer. I’d want to wash my hands,” he says. If you really are a germophobe, Scott says, yes, you can make your own ethyl alcohol-based hand sanitizer at home that could be just as effective — but if you use plain old alcohol, know that the skin on your hands is going to take a beating. “One of the problems with putting alcohol on your hands is that just as it disrupts the membranes in germs it can similarly remove those oils from your skin,” he says. “So with repeated exposure of skin to alcohol, even if it’s diluted, it can slowly over time cause your skin to lose emollient and become at risk of cracking.” And having an open, bleeding wound on your hand puts you at increased risk of bacterial transmission, which can open you up to even more problems.

So why all the fervor surrounding the lack of availability of hand sanitizer?  Wojewoda chalks it up to one simple thing: panic. “There’s also been a run on masks, and we in the hospital can’t get enough masks,” she says. “Which is scary, because we can’t get the equipment we need to do our job in the hospital because people are using them inappropriately.”  Hand sanitizer “is one more thing that makes people feel safe in a time of unknowns.”

REFERENCES:

file:///C:/Users/AZAM%20COMPUTERS/Pictures/efficacy_of_alcoholbased_hand_sanitizers_against_fungi_and_viruses.pdf

https://www.businessinsider.com/things-to-know-about-hand-sanitizer-to-protect-against-coronavirus-2020-3

https://www.cdc.gov/handwashing/show-me-the-science-hand-sanitizer.html

file:///C:/Users/AZAM%20COMPUTERS/Pictures/case%20study%20hand%20hygiene%20intervention.pdf

file:///C:/Users/AZAM%20COMPUTERS/Pictures/US20070281999A1.pdf

In general, the most effective ethanol concentration range has been reported to be greater than 50%, acting in 1 minute.
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