Information

Why do viruses last longer on hard surfaces, like glass, than porous ones


All the papers I've read about survival of viruses outside of the host refer to longer survival times on hard surfaces without explaination. As a layman I would have thought that a virus (who's main environmental dangers are things like UV would survive better on rough or porous surfaces, where they are protected and can hide from the light and weather, not the other way round.

For example, one paper I read recently (although it's an old paper) showed Ebola virus surviving for 50 days on glass but not even 2 on rough materials. Can anyone enlighten me as to what it is about glass that makes such an ideal home for viruses to extend its lifespan by over 25 times?

More scientific papers would be helpful, but the medical community does seem to think that hard surfaces in general preserve viruses better than soft ones. The Mayo Clinic and UK NHS web sites both make that claim, without explanation.


The paper you cited is not about survival on smooth versus rough surfaces; it does, however, mention discrepancies in survival on metallic versus non-metallic surfaces.

From the article you cite (Piercy et al., 2010):

The lack of recovery of virus from metal substrates may be attributed to several factors; previous work (Sommer et al. 1999; Pawar et al. 2005) has shown the binding of micro-organisms to metal surfaces to be poor because of the high surface energy, high electronegative and hydrophilic properties of metal. Other research has also shown that positively charged metallic ions such as copper and silver have a high bactericidal activity (Friedman and Dugan 1968; Bitton and Freihofer 1977; Slawson et al. 1990) and hence by extrapolation may also have a high virucidal activity.

In short, it isn't exactly clear why viruses in particular might have poor survival on metal, but the electrical and chemical properties of metallic surfaces, as well as biological activity of metallic ions that are constantly leached from alloys like steel are all candidates.

The claim may also not apply to all viruses, and the results are not consistent across labs. For example, Sagripanti et al. 2010 find no effect of surface material (aluminum alloy, rubber, or glass) on Ebola, Venezuelan equine encephalitis, Lassa, and Sindbis viruses.

References:

Piercy, T. J., Smither, S. J., Steward, J. A., Eastaugh, L., & Lever, M. S. (2010). The survival of filoviruses in liquids, on solid substrates and in a dynamic aerosol. Journal of applied microbiology, 109(5), 1531-1539.

Sagripanti, J. L., Rom, A. M., & Holland, L. E. (2010). Persistence in darkness of virulent alphaviruses, Ebola virus, and Lassa virus deposited on solid surfaces. Archives of virology, 155(12), 2035-2039.

Bitton, G., & Freihofer, V. (1977). Influence of extracellular polysaccharides on the toxicity of copper and cadmium toward Klebsiella aerogenes. Microbial ecology, 4(2), 119-125.

Friedman, B. A., & Dugan, P. R. (1968). Concentration and accumulation of metallic ions by the bacterium Zoogloea. Dev. Ind. Microbiol, 9, 381-388.

Pawar, D. M., Rossman, M. L., & Chen, J. (2005). Role of curli fimbriae in mediating the cells of enterohaemorrhagic Escherichia coli to attach to abiotic surfaces. Journal of applied microbiology, 99(2), 418-425.

Slawson, R. M., Lee, H., & Trevors, J. T. (1990). Bacterial interactions with silver. BioMetals, 3(3), 151-154.

Sommer, P., Martin-Rouas, C., & Mettler, E. (1999). Influence of the adherent population level on biofilm population, structure and resistance to chlorination. Food microbiology, 16(5), 503-515.


How long can viruses live outside the body?

We have all seen the news reports about the tiny, disgusting germs that are on the surfaces we all encounter every day in our homes and places of work. With cold and flu season upon us, preparations are now being made by many to prevent transmission of viruses, but before you go through drastic measures, there are some important facts about viruses that you should know, such as how long do viruses live on our phones, doorknobs, and keyboards?

There is not one answer to this question. The life of a virus (technically, viruses are not alive) depends on what type of virus it is, the conditions of the environment it is in, as well as the type of surface it is on.

Cold viruses have been shown to survive on indoor surfaces for approximately seven days. Flu viruses, however, are active for only 24 hours.

All viruses have the potential to live on hard surfaces, such as metal and plastic, longer than on fabrics and other soft surfaces. In fact, infectious flu viruses can survive on tissues for only 15 minutes. Viruses tend to also live longer in areas with lower temperatures, low humidity, and low sunlight.

How long these germs are actually capable of infecting you is a different story. In general, viruses are not likely to be a danger on surfaces very long. In fact, while cold viruses can live for several days, their ability to cause infection decreases after approximately 24 hours, and after only five minutes, the amount of flu virus on hands fall to low levels, making transmission much less likely.

The best defense against active viruses remains thorough hand washing. In addition, wiping down surfaces with anti-bacterial or alcohol-based cleaners will help kill viruses and decrease the chances of transmission.

All content of this newsletter is intended for general information purposes only and is not intended or implied to be a substitute for professional medical advice, diagnosis or treatment. Please consult a medical professional before adopting any of the suggestions on this page. You must never disregard professional medical advice or delay seeking medical treatment based upon any content of this newsletter. PROMPTLY CONSULT YOUR PHYSICIAN OR CALL 911 IF YOU BELIEVE YOU HAVE A MEDICAL EMERGENCY.


A growing pile of studies shows our money is dirtier than we think

In modern times, disease spread at an accelerated pace, especially when you compare our modern epidemics to the ones of the past, like the case of Black Death, which took eight years to spread across Europe — and this accelerated pace may be partially due to our dollar bills.

The 75% cotton and 25% linen combination that makes up US dollar bills has been show to have a high bacterial growth, and a slew of research has piled up showing that our money is dirty.

According to some studies, lower-denomination bills like ones and fives, which are some of our most circulated currency, may also be some of our most bacteria-laden bills. One 2010 analysis found that a US note contains 10 bacterial microbes per square centimeter, higher than Australia or New Zealand. A 2017 study on US dollars circulating in New York found pet DNA, traces of cocaine, and over a hundred different strains of bacteria.

Epidemiologist Jennifer Horney, of the University of Delaware, says credit cards are least risky to use, since those can be wiped down. "Pens, hotel room keys, credit cards and card readers can be wiped down with cleaners approved by the EPA for use against emerging viral pathogens as part of routine cleaning to prevent spread," she wrote Insider in an email.

But despite this, disease transmission from money is rare, but that doesn't mean you shouldn't wash your hands, thoroughly and often, before and after touching bills, and go cashless if you can.


COVID-19 FAQ: AskCIDD

Below are answers to some of the most common questions we have been asked about the SARS CoV-2 virus and the COVID-19 disease it causes. These answers are provided by our infectious disease faculty experts. We add a new answers weekly. To stay informed, please consider bookmarking this page.

The most popular of these questions are also being addressed in video form here.

To submit your own question, email [email protected]

Vaccine-Related Questions

Will different virus strains of SARS-CoV-2 affect vaccine development?

Because the vaccines being developed are based on an immune response against multiple sites on virus surface proteins, the small amount of variation that exists globally in SARS-CoV-2 isolates to date is not likely to make a difference in vaccine efficacy. Long term, however, as the virus has more time to evolve, effective first-generation vaccines may need to be revised to cater for growing diversity in the virus. The good news is that so far, SARS-CoV-2 does not appear to be evolving as quickly as flu.

Why get a flu shot this year?

While the flu vaccine won’t protect you against COVID-19, it is especially important to get your flu shot and get it early this year.

Getting a flu shot is important every year because it directly protects you from getting infected with influenza, which can be really miserable while you’re sick, but can also be fatal. A flu shot also indirectly protects your contacts – since you’re less likely to get infected after getting immunized, you’re also less likely to infect your friends and family.

Getting a flu shot this year is particularly important because, like SARS-CoV-2, influenza is a respiratory virus and we want to do everything we can to minimize having two respiratory outbreaks circulating simultaneously in our populations. We don’t know what co-infection or sequential infections for these two viruses looks like, but we worry that infection with one could increase the severity of the other. It’s also possible that infection with one could weaken the immune system and increase susceptibility to the other. A small study from China indicates co-infection may increase the infectious period for COVID-19 and prolong hospital stays (2). Last year in the US, before COVID, the CDC estimated that influenza infections sent around 500,000 people to the hospital (1). If flu vaccine coverage this year is only about the same as last year, the compound effects of influenza and COVID could quickly overwhelm local health care systems. The more people who get their flu shot this year, the more cases of influenza we can prevent.

Another reason to get a flu shot this year is because both SARS-CoV-2 and Influenza are respiratory viruses with similar early symptoms. Experiencing symptoms of flu could lead patients to seek COVID testing. Increasing immunization levels against influenza will help reduce flu infections and avoid needless COVID testing. On the other hand, mistakenly thinking cases of COVID-19 are due to influenza might lead to insufficient isolation periods and increased transmission of SARS-CoV-2.

The social distancing, hand washing, and mask-wearing that we’re all getting really good at to prevent COVID-19 should also be protective against influenza. But, while everyone is anxiously awaiting a COVID-19 vaccine, let’s take advantage of the vaccines we already heave. Flu season in the northern hemisphere begins around November, so you’ll benefit the most if you schedule your flu shot now.

Are the new vaccines safe?

Some people are concerned about the safety of the new COVID-19 vaccines due to the speed at which they were developed.

This is a very fast timeline for a vaccine. The speed has been gained by intentionally making the process as time efficient as possible, not by eliminating steps from development, production, or safety and efficacy assessments. Many steps that would normally be run sequentially, were instead run in parallel, including trials and production (figure 1 https://www.nature.com/article. ).

The Moderna and Pfizer mRNA vaccines will be the first ones available. The advantage of RNA vaccines is that they provide the instructions for the recipient to make a harmless protein that triggers the protective immune response we want. They are also faster to make than traditional vaccines.

The safety and efficacy trials for these mRNA vaccines included 30,000 and 44,000 participants in each, respectively. Half of the participants in each trial received the vaccine and other half received a placebo. Based on the frequency of adverse effects between the two groups in each trial, both vaccines were determined to be safe. The safety monitoring board and the FDA made their approval decisions after considering two months of follow up safety data. And based on the number of participants who reported symptoms of COVID-19, the vaccines were both shown to be highly protective against disease, particularly against severe disease.

We don’t yet know what the duration of immunity will be or if the vaccines will protect against virus transmission. Scientists worry is that unrelated illnesses will be attributed to the vaccine. For example, in the two months after the first 10,000,000 people get vaccinated, 4,000 people will have heart attacks and another 4,000 will have strokes. That’s unfortunate, but it’s the normal rate at which we see those conditions. It’s unrelated to the vaccine.

Vaccine availability will be limited for a while. While there will be multiple options in the future, for most people it will be best to get the vaccine that’s offered to them. Vaccines will be a critical part of our COVID-19 management strategy but they won’t be an immediate magic solution. For now, it’s important to continue with behavioral interventions, including mask wearing and distancing. It’s particularly important to be careful during the holidays.

Transmission-Related Questions

How long does the virus live on surfaces?

A recent study showed that the virus can live on hard, smooth surfaces like metal and glass for up to three days and on cardboard for up to 24 hours. So, this is why, cleaning surfaces with alcohol based cleaner, washing your hands frequently and not touching your face can help to reduce the transmission of the virus. Social distancing is also effective at limiting your contact with contaminated surfaces touched by others in public spaces. An even more recent study shows that virus can remain intact on fabric for up to two days. If you are working outside the home and having contact with lots of people, it is best to change your clothes upon arrival home, and wash them in warm/hot water. This is standard practice for people working in the healthcare industry and probably a good behavior for members of the public to adopt for a while.

Can you get Coronavirus from a package?

We have no evidence of people getting infected from packages, however, given that virus can survive on cardboard for up to a day, it is best to take some precautions. When a package arrives, you can use gloves to handle it or wash hands immediately after, and also let it sit for a few days before opening. If you are getting deliveries of food, wash your hands after handling those bags or boxes.

Can I get virus from someone breathing on me?

Yes. Coronavirus can be expelled in small droplets that are produced when someone coughs, sneezes, talks or breathes. The risk of transmission is highest though for very close contact (less than 3 feet) but we recommend a distance of 6 feet or 2 arms lengths. There is some evidence from recent studies that virus could remain suspended in the air in droplets for up to three hours. This is another good reason to stay home as much as possible.

Can I get COVID-19 a second time?

As of yet, we are unsure of the nature of human immunity to Coronavirus. A recently published study in monkeys has demonstrated that they produce antibodies to the virus, that protected them from a second infection a month later. Over the coming weeks, researches will be studying the antibody levels in the blood of people who have had COVID-19 to understand how strong their immunity is and how long it lasts. If the Coronavirus is like flu, we should expect to have some protection that will last months, until the strains circulating change substantially.

Are my pets at risk? Can they move the virus between people without getting infected?

During this time, we all want to snuggle with our pets but we want to make sure that it’s safe for us and safe for them. At this time, the CDC reports that there is no evidence that animals play a significant role in spreading the virus that causes COVID-19. We are aware of a small number of pets, including cats and dogs, that have been infected with the virus that causes COVID-19, mostly after close contact with people who had active cases of COVID-19. This means you should treat pets as you would any other family members: Like the rest of the members of your household, you should keep your pets in the house and not transfer them between households. And if someone becomes sick, isolate them from the human and non-human members of the house.

We also know the virus can survive on surfaces and objects, and transmit between people that way. It is technically possible that the virus could survive ON a pet for a short while. There’s no evidence that the virus has ever transmitted between people this way, but to be safe, frequent handwashing and avoiding touching your face will be protective.

What should I do if I have a household member with suspected or confirmed infection?

If you have a household member with a suspected or confirmed case, act as if it has been confirmed and as if everyone else in the household is infected. Isolate the sick family member. Give them a room that they don’t have to leave, where they can rest. Leave their food by the door, and whatever else they need. Eliminate or reduce the objects coming out of their room and treat those objects as if they are carrying live virus. If you have two bathrooms in the home, use one specifically for the sick individual. Have them monitor and record their symptoms as long as they can, especially their fever. If things worsen or if another household member develops symptoms, contact a health care provider over the phone or online. Since the entire household will have been exposed, everyone needs to stay inside. Have necessary items delivered or make do with what you have in your home. Call your neighbors and lean on your community. And neighbors help each other. It is safe to drop off bags of groceries in front of your neighbor’s house.

Why does hand washing work to reduce transmission?

The novel Coronavirus is a small sphere with protein spikes on it that allow it to attach to our cells. Below that is an oily layer that coats the virus. When you use detergents like soap or alcohol you disrupt that oily layer and the virus degrades. We also know that on average people touch their faces 23 times an hour! So washing your hands with soap or an alcohol based product will help prevent transmission through that route of infection. It doesn’t mean that you can’t get the virus by other means like inhaling it in droplets or aerosols. We do know from a study done in Hong Kong in the Fall after the SARS outbreak that when the population was being very vigilant with their hygiene that the regular cases of annual flu were substantially reduced. While these data are not specific for Coronavirus they do show that handwashing can reduce the transmission of respiratory transmitted viruses.

How does alcohol kill this virus?

In addition to soap and water, alcohol is a recommended cleaning agent to destroy the coronavirus.

Beth told you in a previous video that soap inactivates the coronavirus by destroying the lipid, or fatty, bilayer that holds the virus together. When a virus’ proteins, lipids and RNA fall apart, the components are no longer viable and virus becomes inactive.

That’s how alcohol works, too. When you soak a virus in alcohol – in this case ethanol or isopropanol – and let it air dry, the alcohol breaks down the fatty bilayer that holds the virus together.

Specifically, you’ll find 70% alcohol easily available. Anything between 60-80% alcohol will work just fine. People will sometimes assume that if 70% alcohol is good at destroying viruses, then 90% must be better. This is NOT true. Anything over 80% alcohol will evaporate quickly and may not have enough time to destroy the lipid membrane sufficiently.

Similarly, alcohol that is weaker than 60% will not destroy the virus’s lipid layer, it has too much water in it. This also means you shouldn’t try to use alcohol that is meant for consumption – a standard bottle of vodka is 80 proof, which means it’s only 40% alcohol and will not effectively destroy the virus.

Essential oils also have a limited effective time of action, due to their volatile nature. So while essential oils like tea tree oil are known for having anti-microbial, non-bleaching properties, these anti-microbial properties are significantly weaker than synthetic compounds.

To destroy the coronavirus, soap is most effective at breaking down the fat layer, and 60-80% alcohol cleaners are also highly effective.

What’s the best way to pay?

Every time you go out to get household necessities, you’re taking on some risk of exposing yourself to the virus or possibly transmitting it to others, if you’re infected and don’t know it. And we all know you have to spend money to buy stuff. In a time of physical distancing and not touching objects other people have just touched, what’s the best way to pay? So handing over a credit card and then getting it back is not ideal. The virus survives reasonably well on plastic and rapid exchanges, like credit card handoffs, are particularly risky. Cash isn’t much better, the rapid exchange means the more rapid decay rate of the virus on paper isn’t really a factor.

Your best options are swiping your credit card yourself and never handing it off or mobile payment with a smartphone where again, you don’t hand anything over and you don’t take anything back. When possible, I prefer to use the self checkout, which protects a potential cashier from me and protects me from them.

Can I spread the virus on my shoes?

It is possible to spread the coronavirus with your shoes. If you’re walking in a common area, particularly indoors, there’s a chance someone sneezed or coughed and gravity sent their respiratory droplets to the floor. If the flooring material is tile, stone, vinyl, or another nonporous material, the virus may survive on it. If you walk through it, you could pick it up on your shoe. If those public floors are cleaned well, the risk is significantly reduced. Proper cleaning means using correctly diluted bleach and letting it sit on the surface for ten minutes before wiping it off. If that wasn’t done, this is still an easily managed problem. When you get home, take your shoes off just inside the door and leave them there. Don’t risk dragging the virus into your house and onto your own floors, especially if you have kids or pets, who might pick it up while crawling or zooming. Stuck to the bottom of your shoe with nowhere to go, the virus will dry out and no longer be viable.

How did a Tiger at the Bronx Zoo get COVID-19? What does that mean for my pets?

You’ve probably heard that a few tigers and other big cats at the Bronx Zoo developed COVID-19-like symptoms. One was tested and was found to be positive. The others are also presumed infected with SARS-COV-2. An asymptomatically infected zookeeper likely unknowingly transmitted the infection. We don't know whether that person transmitted the virus to each of the infected big cats or if that zookeper transmitted the virus to just to one animal, and then the cats infected each other. The animals are all expected to recover. If now you’re worried about your pets, remember, tigers are not very closely related to domestic animals, even your housecats. There’s still no evidence that house pets can transmit the virus to humans. Of course, if you have COVID-19 or suspect you may have it, avoid contact with people and your pet. In that case, your pet could possibly aid in virus transmission to other household members as a fomite, the same way a doorknob could.

What is the timeline from getting infected to becoming infectious?

When someone gets infected, how long does it take for them to become infectious? There are two parts to this.

First: The time from infection to symptoms is called the incubation period. Using large data sets from China, a few studies have estimated this time to be about 5.1 or 5.2 days for people who became symptomatic. Recall that some people never become symptomatic, so as with anything, there is a significant amount of individual variation around these numbers, but for simplicity, let’s move forward with the mean values.

For this novel coronavirus, scientists used data from China to estimate that 44% of secondary cases were infected during the presymptomatic phase of primary infection. This tells us that the Latent period is shorter than incubation period for this virus. This study inferred that infectiousness started around 2.3 days before symptom onset and peaked at 0.7 days before symptom onset.

Second: the time from infection to becoming infectious is called the latent period.

If we combine what we learned about the incubation period and asymptomatic transmission from these studies, that would suggest that the latent period, or the amount of time until an infected person becomes infectious is about 3 days.

How safe is takeout from restaurants? What about cold or uncooked foods?

Some people are worried about the risks associated with ordering takeout. The virus is not transmitted through foods, it’s not a food-borne pathogen like the viruses and bacteria that cause what we often refer to as “food poisoning”. This means that uncooked or cold foods, like salad or sushi, do not pose any additional risk of coronavirus exposure. In general, food prepared in a restaurant kitchen that meets health and safety standards, and there remains open, will be safe. Anything that comes out of a kitchen, including the boxes your food is actually in, should not pose a risk of virus exposure or transmission. The onset of the coronavirus pandemic further prompted additional health and safety measures and chefs and kitchen staff have been wearing masks to prevent the spread of the virus from unknowing asymptomatic infections. The items you should take precautions with include any external packaging that your takeout order may come in. Those bags pass through many hands after they leave the kitchen. For example, if you get your takeout boxes in a plastic bag, toss the bag, wash your hands, and then get into your food. You should also be taking precautions during handoffs, which means delivery or pickups. Any time you’re interacting with someone outside of your household, just keep a safe six foot distance. By taking just a few precautions, you can safely order takeout, help your local restaurants, and enjoy your favorite foods.

Should I be wearing gloves?

We should all be wearing masks when we leave our houses, but are gloves also a necessary precaution for day to day activities? Gloves themselves do not kill the virus. If you’re wearing gloves and you touch something that has virus on it, it can transfer to your gloves. If you then touch your face, you’re just using your gloves to transfer the virus from a source to your face. You can make that mistake with or without gloves on. In some cases, wearing gloves give people a false sense of security, or a sense that they can safely touch things with reduced risk. That will increase a person’s exposure, and in that case gloves are not a good choice. It is more effective to wash your hands frequently and not touch your face than it is to wear gloves and become careless. Wearing gloves does not automatically increase caution or awareness, especially when once the wearer becomes accustomed to them. Gloves are only as effective as handwashing if they’re used properly and disposed of or washed properly. So it’s not necessary for everyone to wear gloves for routine activities.

How can I balance proper handwashing vs. anxiety?

Several people have emailed with concern about striking the right balance between proper handwashing and hypochondria or anxiety as we return to work. First it is important to remember that most transmission is via respiratory droplets but we do know that good handwashing practice prevents other viruses like the flu. You should always wash your hands after you have been to the bathroom of course and before you eat. How frequently you wash your hands beyond that depends on your circumstance. If you work at your desk all day, you could start by wiping down your desk and keyboard when you arrive. Then you could sanitize your hands before you leave your desk to protect others and again as you return to protect yourself from any surfaces you touched. The great thing about wearing a mask, is that it not only reduces your transmission to others from respiratory droplets, but also keeps you from touching your own face. If you work in high traffic, high risk areas, you might choose to use hand sanitizer every hour or so, or between clients, etc.

Can people get re-infected?

CDC guidelines for allowing COVID-19 patients to be considered recovered and no longer infectious can include two consecutive negative diagnostic tests. There have been some accounts of individuals who were infected and presented with symptoms, cleared their symptoms tested negative twice, and returned to work. They later tested positive for a second time, sometimes with symptoms. Were these people actually re-infected?

The truth is we don’t really know. It is not typical for respiratory viruses or other coronaviruses to confer no immunity. There are a few possibilities. First, these tests may be erroneous. It’s possible that some individuals are getting false negative results, meaning they never really cleared the virus. They may have been shedding virus below detectable levels when they tested negative. This seems unlikely because many people must receive two consecutive negative tests before they can return to work but it’s possible. Second, this may be due to a different kind of testing error. Some patients may be receiving false positives after fully recovering. In this case, the tests may be picking up nonviable fragments of the virus’s genetic material that remain in the patient’s mucosal members after an infection. Those viral fragments aren’t capable of causing new infections. However, they wouldn’t produce a second round of symptoms in a patient. Third, it is possible that people are in fact becoming re-infected rather quickly after recovering from infection. One instance where positive tests have been documented following recovery is on naval ships, where sailors are in very close quarters and may result in high levels of re-exposure. While not impossible, this is counter to much of what we think we understand about respiratory viruses and coronaviruses. It would be surprising and unexpected if infection confers virtually no immunity for some individuals.

A few different studies have shown that humans who recover from COVID-19 show a significant antibody response up to 14 days after recovery, with no indications of a rapid decline in immunity. Non-human primates who recover from experimental infections with SARS-CoV-2 do not get re-infected when they are challenged with the virus a second time. If some people are actually getting re-infected, is there something special about them or their environment? We don’t definitively know what is happening with people who test positive and develop symptoms after recovering from SARS-CoV-2 infection. This continues to be an area where we need more information to fully understand what’s happening. The duration of immunity following infection will be a critical piece of information in our attempts to return to social interactions.

Can someone return to work if they are immunocompromised?

For most people, a return to work following quarantine will present an increase in contacts, and therefore an increase in the risk of exposure to COVID-19. For immunocompromised people, we expect that there is an increased risk of becoming infected and experiencing severe symptoms, but we actually don’t have enough data yet to know for certain. However, it is extremely important to reduce risk and avoid infection for people who are immunocompromised. As economies and workplaces resume operations, this means working remotely (or allowing other to work remotely) as much as possible. It is also important to consciously reduce risk of exposure while out: be extra vigilant about masks, social distancing, and hand washing. Close contacts with people outside of the household should be avoided entirely. The CDC defines close contacts are interactions over less than six feet of distance that are over 15 minutes long.

If an immunocompromised individual’s work involves contact with a lot of people – like a restaurant server or bartender, educator, health care worker – it is even more important for them and everyone around them to wear masks and keep the necessary six feet of distance. We must consider the additional possibility that an infected, immunocompromised individual may shed virus for a longer period of time and should be vigilant in protecting themselves as well as everyone around them. Be mindful of yourself and your coworkers, remember that everyone has different health care needs and concerns. Our communities are only as safe as our least cared for members.

Is wearing a face shield the same as wearing a mask?

As people return to work and spend time in their communities, it is important to discuss the efficacy of different facial coverings. There has also been some misinformation being shared in the media about this lately. Plastic face shields are commonly used by medical personnel as barrier protection against splashes and splatters of respiratory secretions that occur during risky/up close interactions with patients. These same health care personnel also always wear either an N95 respirator or a surgical mask at the same time to prevent inhalation of virus. There is no evidence that face shields, that are open by design, prevent the inhalation or exhalation of viruses. For the average member of the public, who is not exposed to splash or splatter events in the face, a shield is unhelpful. A cloth face covering, instead, is the best option for protection. Cloth masks are best at preventing others from being exposed to virus from the respiratory tract of the wearer. They also provide some protection to the wearer, against larger droplets that may carry virus. So, be kind and wear a mask for others. If we all do this, we will drastically reduce transmission of the virus.

Can you get Coronavirus from flushing the toilet?

Some recent studies have demonstrated that virus, present in fecal matter, can get sprayed around bathrooms following the flushing of a toilet. What is not clear is whether this virus is ‘infectious’. What that means is whether the virus in the air or on bathroom surfaces would be able to cause disease if it got entry into a person’s respiratory tract. The best advice is to put the toilet seat cover lid down before you flush to limit the spray and protect others who come after you. Also treat all surfaces in bathrooms like they might be contaminated. Wash your hands thoroughly and use a paper towel to open the door handle on the way out. Public bathrooms commonly do not have seat covers, however. Establishments might like to install them and add signage indicating to put them down before flushing. Alternatively, establishments could close alternating stalls to use to provide some physical distance between users. If it is a small bathroom with only a few stalls you could limit occupancy of the bathroom to one person at a time.

What can be done to increase airflow in offices?

We know that good airflow can help reduce the possibility of infection. That is why the risk of transmission is much lower outdoors than indoors. Opening windows and doors will help with airflow and this process can also be assisted with the use of fans. This is not an option in all buildings, however, and in colder regions during winter. Occupants can check with their building facilities staff to make sure the mechanical operations for airflow are functioning and have been effectively restarted/filters cleaned, particularly if they have been shut down. They can also discuss whether it is possible to increase the air turnover rate. This also be more difficult to do in the colder months, however, when rapid air turnover makes the building harder to heat. Building operations staff can consult the CDC website for an official list of these recommendations.

Can the virus be transmitted during sex?

Coronavirus is not a sexually transmitted virus however, there has been very little research in this area. The virus can be transmitted during sex via inhalation of respiratory droplets and the exchange of saliva during kissing. We also know that virus is present in the feces. The best advice is to avoid having sex with partners that live outside your household or who are not in your quarantine bubble/close contacts. You might consider making the best of technology to have sex safely by phone or virtually. If you do plan to have sex with someone not in your household or close contacts, try to keep the number of partners low, both partners should wear a mask, avoid kissing and oral/anal play, and select positions that have partners facing in opposite directions. If you can, talk about your expectations in advance. Importantly, everyone should avoid having sex if you or your partner has symptoms of COVID-19 or if one of you has recently been exposed to an infected person.

What is the evidence that SARS-CoV-2 might be airborne?

Several months ago, a coalition of scientists urged the WHO to change its messaging to indicate that SARS-CoV-2 could be transmitted by aerosols. Recently, the CDC provided guidance on its website that SARS-CoV-2 might be airborne and then rapidly removed the information. So, what does the evidence say and what does it mean for how to protect yourself? It is generally agreed that like the flu virus, most of SARS-CoV-2 transmission occurs via large droplets that are expelled while talking, breathing, singing, coughing and sneezing. The size of those droplets is such that they fall out of the air rapidly and do not travel very far. This is the basis of the guidance for staying 6 feet apart and wearing masks when you must be closer to people. It also agrees with the data showing that most infections occur between close contacts. There is also evidence, however, that the virus can be expelled in much smaller particles called aerosols that can travel further (some data showing 27 feet) and that can remain in the air for longer periods. Air sampling in hospitals for example has found evidence of virus. The question that remains is whether the virus from these aerosols can infect people. Part of that equation is understanding just how much virus you need to inhale to become infected. We just don’t know. There is also some evidence from studies of infection clusters suggesting airborne transmission. Infections that were tied to a bus in China and a choir in Washington demonstrated that people who became infected were not necessarily sitting near to the infected individual. Additionally, a recent study on an international flight has demonstrated that an infected passenger in business class mostly infected people around him but also people in the economy section. Infection of people in economy could have occurred by aerosols since the sections of the plane do not mix, although contact with the infected individual may also have occurred at check-in or during baggage pickup. There is also an example of infection happening in a restaurant, with exposure likely due to virus dissemination by an air conditioning unit. These studies indicate that aerosol transmission may be possible indoors. As people move into the colder months in the Northern hemisphere, it is important to weigh up the potential risk of aerosol transmission when selecting your indoor activities. The rate of air turnover or ventilation, length of exposure, degree of crowding/ability to keep some distance and whether people are wearing masks should be considered.

Public Health Questions

How long will this shutdown last?

This is the question everyone is asking. The important thing to remember with the guidelines you’re receiving is that they are a direct response to what the virus is doing. To paraphrase Dr. Anthony Fauci’s (head of the National Institutes of Health) recent comments, the virus makes the timeline, not us. We are monitoring the numbers of cases and deaths and constantly updating the guidelines you’re receiving. Today, March 26, the US just passed 1,000 COVID-19 deaths and we know this definitely won’t be over in a few weeks. We need to continue to have these important interventions in place for a while.

Without these interventions, we would be facing more cases and even more deaths. We need to continue to slow transmission. Returning to high contact lifestyles too soon would lead to a rapid increase in new cases and create an even bigger outbreak than what we’re facing right now. It would lead to a new shutdown that will be more extensive and last longer. Letting up too soon will be a waste of all the hard work you’ve already done staying home and upending your lives.

Scientists and doctors need this time to build knowledge on this new virus. We need to increase testing ability, prepare hospitals to provide treatment and care for a lot of patients, and design drugs and vaccines. In the next few weeks, we are not going to go back to the way things were, but we will find a new normal. We will see continuously updated interventions through the summer and a reassessment in the Fall, and it’s really important that we prevent a large resurgence then.

How is this outbreak different from the flu?

First this is a new virus. That means our bodies have not seen this virus before and we are unlikely to have any antibodies. This virus seems to be spreading through the human population much faster than flu, and part of that has to do with the fact that all of us are susceptible. With the flu, most of us are carrying some level of antibody protection from a previous year’s exposure or from a vaccine. Additionally, the case fatality rate is estimated to be 10 times higher for COVID-19 that the flu. Lastly, this virus is new to medical personnel, too. They are learning how best to both take care of patients and possibly treat it.

Will this virus return in the Fall?

Given that the novel Coronavirus is a respiratory transmitted virus, we expect that at some point there will be season patterns of transmission, rising in frequency in the colder months just like flu. Because the virus is just sweeping through populations however and people are highly susceptible it may not behave in this predictable manner initially. Additionally, we will first need to see how the virus spreads through the summer months. That pattern will be dependent on a range of factors including transmission in warmer/humid weather, the degree of immunity in the population and our level of physical distancing.

There is a lot of discussion about mortality rates. Why is this difficult to calculate?

During an epidemic, you’ll hear epidemiologists talk about the Case Fatality Rate. The Case Fatality Rate is the proportion of total cases that results in fatalities. This is a population level measurement. With this coronavirus pandemic, we know there are asymptomatic cases, which aren’t diagnosed, as well as symptomatic cases that aren’t diagnosed due to a lack of testing. This means that our records are incomplete for both the denominator – which is the total number of cases – and the numerator- which is the total number of COVID deaths. These numbers are currently skewed towards identifying symptomatic cases and, severe cases, which are more likely to have negative outcomes. Model estimates have tried to account for those biases. For this pandemic, it’s not terribly important for everyone to know a precise number for the case fatality rate, it is more important to realize that even a low case fatality rate in a fully susceptible population like ours, will cause a lot of deaths. You can help reduce these numbers by continuing to reduce transmission. Follow your local current guidelines on physical distancing to minimize the total number of cases – stay home, and stay six feet away from people when you need to go out.

What does it mean for a virus to peak?

To figure out where we are in the progress of an epidemic while it’s happening, epidemiologists plot the number of new cases per day, which is called the epidemic curve. You’ve been seeing these plots for coronavirus at national levels, for your state, your county, and maybe your town. During the period when the number of new cases per day is increasing, we are in a time before the peak of the epidemic. When the number of new cases per day begins to consistently decrease, we assess that we might be past the peak. It’s not really possible to define the true peak until after the epidemic is over. Even after cases have started to decline, there’s always a chance that they could rise again if control measure are lifted too early. For this particular virus, we know there are lags in reporting and an incubation period, so the cases reported today represent infections that were acquired sometime in the past two weeks. Additionally, if we see the cases start to drop and people become complacent with their physical distancing, there’s a good chance we’ll see a large resurgence in cases, which could surpass the first wave of cases. It’s important for epidemiologists and policymakers to keep an eye on these epidemic curves to assess the interventions put in place and update them as frequently as necessary. So the peak of an epidemic curve is the day with the most cases per day.

Are pools/oceans/lakes safe? Can coronavirus pass through water?

As summer approaches, people are asking about the safety of pools, oceans, and lakes. There are two parts to this answer. First, the virus is not transmitted through water, whether it’s chlorinated water, fresh water, or salt water. So water itself is not risky. Second, we know the virus is transmitted between people and aggregations of people are particularly risky. So the safety of pools and beaches depends entirely on crowds. Crowds at the pool, ocean, or lake are NOT safe and will help spread the virus. Beaches where you can’t maintain at least six feet of space are also risky. And locker rooms at the pool or the beach are very risky because the virus may survive for a long time in those locations. If your household has a pool that no one else uses, that would be a safe option. If you can get directly from your house to a beach where you probably won’t see anyone else, that’s also a safe option. But community pools, crowded beaches, and shared locker room spaces are risky and should be avoided. Unfortunately, for most of us, that means we’ll have to get our beach fix and pool vibes from pictures and memories for now.

My county or state is lifting restrictions - can I go back to normal now?

Some areas are starting to ease restrictions on movement and gatherings. Some businesses will start to reopen. That does NOT mean it’s safe for you to return to your life, as it was before this pandemic disruption. Because it definitely is not. The goal of restricting movement and interactions was to “flatten the curve”. Which meant we wanted to have fewer new cases per day so that our health care systems weren’t overwhelmed. The idea was to use that time to improve our ability to manage this virus. We needed to increase our capacity to test, isolate the infectious and trace their contacts, care for the symptomatic, and quarantine the exposed. If we take the first step in that process, which is testing, for the past week, we’ve been testing about 248,000 people per day in the US. Estimates on how many people we need to be able to test per day range from 900,000 to 4 million. These are absolute minimums for preparedness for the first step in a multi-step management and mitigation process. We’re well behind on where we need to be to meet our testing needs. In Pennsylvania, we’re testing fewer than 6,000 people per day and our target should be closer to ten times that - about 60,000 people per day. So while restrictions may be changing in your area, pay careful attention to what the new restrictions permit. In many cases, these don’t allow for significant increases in activities that would lead to close contact or large aggregations. Most recommendations specify maintaining physical distance outside of the household and continuing to work remotely. Finally, many areas that are reopening and allowing for aggregations and close contacts are doing so prematurely. The risk has not passed and our capacity has not improved enough. To avoid putting yourself and your household members at risk, I encourage everyone to maintain physical distancing practices as much as possible.

How can I return to work – especially in another county?

While counties are shifting from the red phase to the yellow phase, some people are caught in between, They had been commuting across county lines in pre-pandemic times. There’s technically no ‘legal’ guidelines here but there are three important things to consider.

The first is that the county-level phases are determined by local numbers of COVID-19 cases and estimated transmission levels. At this point, many studies have shown independently that transmission very often happens inside the home. In fact, the household is the most common place for transmission of this coronavirus. The attack rate is the proportion of people who became infected out of all the people at risk during a period of time. In some areas, the estimated attack rate in households for adults is as high as 28%. So the most responsible way to think about how these phases apply to you is to use the location of your residence to determine your level of restrictions.

Second, businesses in counties that are in the yellow phase must provide teleworking options to employees who can work remotely. Further, any return to work places will require that all employees wear masks and maintain at least six feet of distance from others – with an allowance for more distance if employees are speaking or really projecting their voices, because that can also project respiratory droplets. Keeping a safe distance may require changing the layout of office furniture or altering foot traffic patterns to reinforce personal space, especially in common areas. Physical spaces will also need improved ventilation and disinfection. And whenever possible, workplaces will hold meetings virtually, instead of in-person. So just because a business is allowed to open in the yellow phase, doesn't mean all employees will be or should be back on site.

Third, remember that PA, like most states, is still well below the testing goal, which means we’re testing far fewer people than necessary to test to get ahead of the outbreak. Testing is just the first step to quickly identifying cases and preventing transmission.

So even if you live in a county in the yellow phase, everyone who can should continue to stay at home and avoid going out as much as possible.

Is air pollution related to COVID-19?

Patients with existing respiratory condition are at risk for developing more severe cases of COVID-19. There are a lot of factors that can contribute to respiratory conditions, including genetic factors, behaviors - like smoking, and environmental characteristics, like air quality. A lifetime of inhaling air that is polluted with particular matter or irritating gasses can exacerbate existing respiratory conditions. And, even in healthy people, inhaling particulate matter, nitrogen dioxide, or ozone can damage or irritate airways. This may contribute to the likelihood of infection upon exposure or the severity of disease upon infection.

However, we can’t quantify the direct impact of air pollution on COVID-19. In many areas with high levels of air pollution and large outbreaks of COVID-19, we also see a number of confounding factors, like high population density, which leads to increased transmission between people and larger outbreaks.

In the wake of large-scale coronavirus related shutdowns in manufacturing and movement, we’ve seen noticeable improvements in air quality. As we develop ways to incorporate these activities into our new COVID-resilient communities, it is reasonable to think that efforts to maintain cleaner air will contribute to health improvements in a number of ways.

How can universities function in the fall?

Right now, universities around the world are discussing how they might return to resident instruction for the fall term and strategies range from carrying on exactly as before to having all instruction occur remotely.

Some people have erroneously said that the average college student, aged 18-23, is at minimal or no risk of COVID-19 infection. This is definitely NOT true. Severe cases, while more likely in older individuals, are found in younger, healthy people as well. We are now also seeing sequelae associated with mild clinical cases in young, healthy patients, such as severe or fatal complications due to blood clots. And we are continuing to see persistent lung tissue scarring, which follows severe symptomatic cases.

Let’s also be aware that universities welcome students of all ages and many college students, of any age, may have health conditions that make them more vulnerable to severe COVID-19 infection than their peers. Universities need to create a safe environment for all their students and personnel. Many people also think that students are the only demographic to worry about in a return to university operations but that is not true. Universities need students but they also need staff, administration, and instructors or faculty to function. And many of those employees are in high risk groups. And finally, the community that surrounds and supports the university makes enormous contributions to the day to day functioning of collegiate lives. So universities must also consider the health and safety of the members of those communities. University operations are vast and complex and require many healthy and safe people in many roles to function.

By nature, a college campus a high density environment that brings together people from different locations and perspectives. While doing this creates a rich intellectual environment, it also creates a risk for viral introduction and increased transmission on campus and in the surrounding community. A return to campus represents an increase population movement and local population density. Remember, a return to campus may represent an increase in risk for some and a decrease for others depending on where students and employees have spent their quarantine.

Given all of that it IS possible to find a safe way to return to campuses. Universities can benefit from flexibility, creativity, and innovation while building plans and policies from the ground up to find new ways of teaching to take advantage of low-contact formats. No school is required to take a reductive approach and focus only on diluting what was previously offered. But it is critical that prevention, detection, and care are at the forefront of the public health plan.

Many students do fall into a young and healthy demographic, which means they may be more likely to experience asymptomatic infections so testing must be frequent and rapid and it must be executed at a capacity that reflects the size of the on-campus population of each university. Testing capacity may even be used to guide the new size of on-campus cohorts. It’s important to note that behavioral interventions are going to continue to be our primary tool against this virus, so universities need full cooperation from everyone in social distancing, voluntary testing, contact tracing, and isolation because public health is ultimately the sum of private behaviors.

Are university students actually low risk enough to reopen without major changes?

Some universities have announced that they believe their students are at low risk for severe cases of COVID-19. They feel that this will allow them to re-open in the fall without presenting a substantial risk to the students. This is incorrect and worrisome for a few reasons. First, not all college students are at low risk for severe clinical cases of COVID-19. Most universities have students of all ages and medical histories, and some will certainly fall into conventionally high risk groups for COVID-19. Second, we are just beginning to see some of severe sequelae of this disease. Some healthy, young adults who present with mild COVID-19 infections recover from the virus only to experience complications from blood clots, including severe, sometimes fatal strokes. While rare, this is occurring in numbers that are highly atypical for these patients’ age and medical history. Third, a university does not function solely with undergraduate students. Graduate students, staff, and instructors all have very high rates of contact with undergraduates. Many of those university personnel are at high risk of severe COVID-19 infections and universities simply can’t function without them.

In order to open safely, universities should consider a wide range of preventative interventions and health care resources. University’s should consider restructuring educational interactions. Any return to instruction will lead to an increase in contacts so schools need to make testing widely available, encourage compliance with contact tracing, and provide extensive support for isolation and quarantine.

How many of the reported cases in my state are asymptomatic?

This is a difficult question to answer. In controlled studies where cross sections of the population were screened for SARS-CoV-2, regardless of whether they had symptoms, it appears that 25-50% of the population has no symptoms during the course of their illness that would make them think they had COVID-19. This is different from pre-symptomatic individuals, that are capable of transmitting but may begin to show symptoms in a few days time. So, when a state reports say 70,000 cases, most of those are going to be from symptomatic individuals who sought care and testing. Some proportion will likely be asymptomatic – but only in situations where people sought tests despite feeling well, likely because they were exposed to a known positive case or because routine testing was part of their workplace. This means that the numbers of reported cases are likely a massive underestimate of the actual numbers of cases, particularly asymptomatic individuals. Widespread testing for antibodies, once the accuracy of these tests is assured, will ultimately reveal the true numbers of cases that were present in a population and the proportion that were asymptomatic.

Why are disease models always wrong?

Models are always wrong for two reasons: abstraction and influence. However, mathematical models of diseases can be extremely useful and informative when trying to understand how a disease may spread or how a particular intervention strategy may impact that spread. But it’s critical to understand a model’s design and purpose to be able to interpret it correctly. In other words, let’s quickly break down an often cited quote that is attributed to British statistician George Box, “All models are wrong but some models are useful.”

The first thing to know about all models is that they are designed as abstractions of reality. They are meant to represent only some parts of reality so they are intentionally reductive. No model includes every single element of the real world doing so would be both impossible and would render the model useless. What a model includes and leaves out is based on what it is designed to accomplish. In general, ‘useful’ models are designed to identify the underlying mechanisms or processes that give rise to outcomes – whether it’s disease transmission, the adoption of protective behaviors, vaccine uptake, or any other important factors in a disease outbreak. By identifying the critical elements and understanding their interactions, models can help us learn how to manage and mitigate outbreaks. Even if a model incorrectly projects the size of an outbreak or the rate of its increase, that model may be incredibly useful for identifying critical contributing factors to the spread of a pathogen and assist in management and prevention.

The other reason that models are always wrong is because models can influence policy makers, intervention strategies, and individual behaviors. In doing so, models can incite changes that alter outbreak trajectories. If a model reveals paths of action that can save lives or prevent disease, those actions are often taken. The end result would be fewer cases than the model predicted, meaning the model was ‘wrong’ in its predictions but it was extremely useful.

Every disease model is a reductive abstraction of reality. Many models provide insights that help reduce or prevent morbidity and mortality.

Understanding the protests in the context of the pandemic is important.

Both the pandemic and police brutality, along with countless additional forms of systemic racism and inequality, are disproportionately killing Black Americans. They are equally serious symptoms of underlying systemic inequality. They are imminent threats to the health and safety of Black Americans.

COVID-19 has disproportionately sickened and killed Black residents in America. High density housing in urban areas aided transmission, reduced access to health care allow infections to simmer, and continued essential work increases exposure. In New York City alone, the novel coronavirus caused more than twice as many Black deaths (per 100,000 population) than white or Asian deaths.

Racial inequities in health and justice are both serious issues that require urgent attention and systemic solutions. Protestors are fighting to address both of these issues, and many more.

Following a few months of quarantine, protesting presents an increase in social contacts, which increases participants’ risk of exposure and transmission of SARS-CoV-2. To protest as safely as possible, wear a mask, ask others to wear masks, and don’t touch your face. Keep hand sanitizer with you and use it frequently. Avoid face to face interactions or conflicts and do your best to maintain a six foot radius of physical distance, though we know this can be difficult. Incorporate noisemakers or percussion instruments to reduce your shouting or chanting, which can forcefully release respiratory droplets containing virus.

Luckily, protests are outdoors, which mitigates transmission, and presents a significantly lower risk of transmission than indoor activities or sustained interactions.

We encourage people to be informed. Everyone needs to decide for themselves what level of risk they are comfortable with. People who can’t participate in protests for any reason but want to support the Black Lives Matter movement can be involved in a number of ways, from monetary donations to reading and learning about the breadth of racial inequities in America and their widespread negative outcomes, and most importantly, voting.

If bars and restaurants are open, are they safe?

Following a period of lockdown, many bars and restaurants have re-opened their doors. However, this does not mean that they are safe. Many new clusters of infection have been traced back to dining and drinking experiences. These activities are actually particularly risky because a mask can’t be worn while eating or drinking.

Outdoor seating offers some protection due to air flow, but sitting with people who are not in your household creates additional close contacts. This poses a significant risk for you and everyone in your household. Consuming alcohol can also cause people to let their guard down and be less vigilant about practicing recently acquired behaviors to reduce contact with others and maintain distance from non-household members. Takeout is still a great, safe option for supporting local businesses and enjoying your favorite foods.

How should I decide if I send my kids back to school?

This is a difficult decision for parents, wanting their kids to have the improved educational and social experience of in-person school, while maintaining the health of their children and their family members. We will try to provide some advice based on scientific evidence. Ideally, school districts will offer both in-person and remote school options. Parents should consider three factors when making a decision the personal health status of their kids and family members, the behavior of the virus in their local areas, whether it is peaking or controlled and whether their school district has plans in place to make in-person school safer.

There is some reassuring news. Kids under 18 are 30-50% less likely to get COVID and also therefore be a part of a transmission cycle. This is particularly true for kids under the age of 12. Children do get COVID, however, and can occasionally experience severe forms of the disease, particularly if they have underlying conditions. The risk is not zero. In Europe, in communities that had flattened the curve and then sent kids back to schools with extra safety precautions in place, there was little evidence of outbreaks in association with schools. In Sweden, that did little to flatten the curve, so that there was lots of virus circulating, there were outbreaks and some deaths in association with schools.

Parents should check-in with their school district to see what precautions will be taken in the Fall. First, all students and teachers should be required to wear cloth masks (not face shields) to limit exposure to the virus. Second there should be a plan to maintain physical distancing between students as much as possible. This will vary depending on the school and their type of facilities. Some examples include reducing instruction to small and static groups, alternating student days of attendance or time shifting their schedules, having children eat in their classrooms rather than in crowded cafeterias, and altered curriculum schedules to reduce the need to move between classrooms/subjects each day. Parents may be asked to drive their children to school, if they can, to help reduce the numbers of kids on busses. Air handling facilities should be evaluated in school buildings to improve flow and filtration. In some buildings this may include opening windows and using fans, weather permitting. Classrooms, bathrooms, busses, should also be sanitized nightly if possible. There should also be a clear plan for sending any child home that exhibits sickness that could potentially be COVID-19. In the Fall, this will include students that likely have the common cold or flu. Schools will develop their own criteria for when a student could safely return that may involve a period of remote school or passing a COVID test.

At home, there are a range of things parents and families can do to keep their own kids and the kids of others healthy. Everyone in your family should get the flu shot to reduce flu incidence. Monitor kids’ health including their temperatures and keep any children with COVID-like symptoms at home. Families can also play their part more broadly by wearing masks in public, physical distancing and limiting their social contacts to keep from being the source of transmission into schools.

If your child is immunocompromised or has underlying health conditions like diabetes, asthma, etc, you should check with school to see if they have additional practices to protect kids in this category. Also, consult your GP, but for these kids a remote school option may be the best and safest choice. The same will be true if there are members of your household with underlying conditions that put them at heightened risk or if the children will have contact with grandparents. It is also possible that children may expect to return to in-person school but if virus worsens in a community that they may need to revert to remote learning. Schools should be prepared for this potential outcome.

My advice is to ask a lot of questions of your school district and stay informed about what is happening with respect to the virus in your community. Governors will have a role to play in communicating that risk. You can also consult websites that are based on scientific evidence like the CDC and your local state health department.

Gyms continue to pose a risk for the spread of COVID-19. For the foreseeable future, all indoor fitness should look a bit different than it has in the past.

Fitness classes, studios, and indoor gyms present a unique risk to instructors and attendees. Countries that had very effective control measures and have been able to reopen are providing valuable information. With very high levels of surveillance and testing, many resurgences in cases and outbreaks have been linked directly to fitness activities. After reopening in May, Japan traced clusters of cases back to gyms. A well-documented example with careful contact tracing highlighted how a fitness studio in South Korea spread the virus amongst its instructors and members.

These resurgences were detected because of excellent outbreak management, a very high testing rate, and very good contact tracing. These are all things the US does not have.

These outbreaks have confirmed our suspicions that the virus transmits effectively during fitness activities, when people exhale and inhale forcefully. This allows the virus to travel farther in respiratory emissions during physical exertion than it does during normal breathing and speaking. This is true indoors and outdoors but the effects on transmission are magnified indoors.

Small, outdoor fitness and dance classes with significant spacing between participants present a relatively low risk of transmission.

Indoor activities with few participants and little interaction (physical contact, face to face conversations) present a risk but, depending on the facility and the number of users, it may be manageable with drastically reduced capacity, improved ventilation, and frequent cleaning of all surfaces and equipment.

Activities that involve direct contact between members from different households present a very high risk of transmission. This includes activities like partner yoga and any training that involves sparring with someone.

Gyms will be safer when there are very few local cases, so it’s important to be aware of and responsive to what’s going on in your area.

Are hospitals changing the way they report COVID-19 data?

The Department of Health and Human Services (HHS) recently announced a request that all US hospitals change the way they have been reporting COVID-19 data (number of tests administered, positive results, etc.). Hospitals had been reporting to the CDC’s National Healthcare Safety Network but they must now report to the new HHS Protect system. This is a surprising move because collecting and reporting public health data has long been a core function of the CDC. The CDC has trained expertise to perform these tasks as well as the necessary infrastructure. The middle of a pandemic is an unusual and particularly ill-advised time to change data reporting procedures for several reasons. We highlight three concerns below.

First, the HHS requires data in a different format for reporting than the CDC requires. Hospitals have existing protocols and personnel in place for CDC reporting. They are understaffed and changing the way they are required to report data will require additional work and staff. Second, the shift has fueled widespread concerns about continuity in reporting. Continuity is important for tracking trends in numbers of cases to implement outbreak response accordingly. The CDC analyzes the data they receive and use them to guide responses and recommendations. The HHS claims the new reporting system will be more responsive and efficient in allocating supplies to the areas where they are needed most. However, the HHS has not demonstrated how or why their system will be an improvement on the CDC’s system. Third, the CDC also de-identifies and aggregates data to make it available for others to access. Experts in public health and epidemiology have been relying on the CDC data reports for their own work contributions to manage this outbreak continue to come from a variety of groups and data accessibility has been critical for those efforts. The change in data reporting has brought questions about transparency and data availability with the new data management process. The HHS has not answered questions regarding how quickly they will make de-identified available to the public.

Herd immunity is the concept that some susceptible individuals in a population can receive indirect protection from an infection if they mostly come into contact with people who are immune to the infection. The more immunity there is in a population, the fewer susceptible people there are, and the more likely they are to have this indirect protection.

The threshold level of immunity in a population required to actually break chains of transmission and eliminate a pathogen from a population depends on the reproductive number of the pathogen, or how well it transmits between people. For a virus like measles, which is one of the most infectious human pathogens, the proportion of the population that must be immune to the virus to protect the susceptibles is somewhere around 95% of the total population, which is very high. For a virus like SARS-CoV-2, which causes COVID-19, that proportion is around 66%, and while that’s lower than it is for measles, it’s still very high.

We started 2020 with a population level immunity of zero, so getting to a 66% level of population immunity cannot happen in a matter of a few years, much less a few months. About 9 months into this epidemic, in the US, we have approximately 3% population level immunity and it has cost us nearly 200,000 lives. This level of population immunity does not provide indirect protection to very many susceptible people. While a vaccine will help increase immunity in the population, it will be a long time before we have a safe and effective vaccine that is available to 66% of the nation’s population, which would be over 200 hundred million people.

Another way we can indirectly protect susceptible individuals from infection is to reduce the number of infections and infectious individuals in the population. We can do this with behavioral interventions, by reducing contacts, and by maintaining physical distance when we’re outside out household. All of those things will reduce the number of infections and infectious people in our population and will help protect susceptible individuals. When the virus is at very low levels, we can control it effectively and gradually increase our contacts and activities. While other countries have achieved this goal using all the same tools that we have available, we are not there yet.

Social Distancing & PPE-Related Questions

Should I go do my own shopping or have my items selected and delivered by someone else?

If you’re unwell or if you have any reason to suspect you may have been exposed, even if you feel fine, don't go out. Don't’ go anywhere. Stay home, monitor your symptoms, and isolate yourself. Have a friend, neighbor, or delivery service drop off necessities in front of your door.

If you have had no suspected exposure to the virus and you have no symptoms, you can go shopping yourself. Limit the number of trips you make, so buy enough for a week or two. Be very deliberate and surgical about it: Make a list, go the store, get what you need, come home, and wash your hands. Use the self-checkout if you can. Wash your hands and don't touch your face.

I know we’re supposed to stay at home, but can I go for a walk outside?

As long as you’re feeling healthy and don’t think you’ve been exposed to the virus, going for a walk is an excellent idea. Fresh air and a change of scenery will lift your spirits. However, the rules of physical distancing still apply. Don’t get close to people and maintain your six feet of separation. We’re seeing some cases where people are advised to go out to parks and then the parks become crowded and have to close. So go outside but only if you can maintain responsible distance from others.

How do the physical distancing guidelines translate for sharing a path with runners or bikers?

How do we share outdoor space responsibly? If you’re walking, running, or biking side by side with someone, follow the usual rules: six feet of distance.

If you’re behind someone who is walking, running, or biking, the guidelines are a little different. A preliminary study by aerodynamicists using simulations of microdroplets in saliva left behind by a walker, runner, and cyclist shows that your best bet is to stay out of the slipstream, also know as their draft. In other words, to minimize your risk of exposure to viral particles from an athlete ahead of you, avoid drafting. Drafting involves placing yourself directly behind someone to reduce wind resistance. If you’ve been intentionally drafting to gain a competitive advantage, you should stop for now. The study says that to avoid the slipstream of someone directly in front of you, you need to keep a distance of about 5 yards between you and someone walking ahead of you, about 10 yards between you and someone running ahead of you, and a staggering 20 yards between you and someone cycling ahead of you.

If you don’t have quite that much space, you can drastically reduce your risk of exposure by staggering your position, or following someone diagonally instead of being directly behind them. So if a runner or cyclist passes you, offset your position so you’re diagonally behind them, not directly behind them, and keep your six feet of distance the whole time. And if you’re going to pass someone, position yourself diagonally behind them with plenty of distance to spare. So as you approach them, you’re not in their draft.

Do I need a mask outside, alone?

The universal masking recommendation says that all Pennsylvanians should wear a mask anytime they need to leave their homes. Masks are good for two things: protecting other people from your respiratory droplets and protecting you from others’ respiratory droplets. If you’re going outdoors and you’re not going to see another person, even from a distance, while you’re out walking your dog, you don’t need a mask. If there’s even a chance you might see another person, bring your mask with you so that if you see someone in the distance, you have plenty of time to put it on before you’re near them.

Keep in mind that if you’re in a city or a populated area, including a college campus, you probably always need to wear a mask whenever you’re outside. This question came to us from someone in an isolated area with a lot of outdoor space.

What are quarantine ‘pods’ or ‘bubbles’?

As restrictions begin to ease, one strategy for increasing your socialization but maintaining safety is to choose to socialize with only one other family group. These quarantine ‘pods’ or ‘bubbles’ can still be relatively safe if both households are practicing social distancing. You should keep the size of the bubble small, fewer than 10 people. You can also reduce your risk in your bubble by socializing outdoors, washing your hands frequently, and wearing a mask as talking can lead to lots of expelled virus from infected individuals. If you are eating together, get people to bring their own cutlery and dishware and cool side dishes. Hot food can be served up safely directly from the grill or oven pans with utensils and people should all use hand sanitizer before they eat.

Can I let workmen or friends into my house to use the bathroom?

If you need to let a workman into your house, you should both wear masks and keep your distance. You can point them in the direction of the repair rather than following close behind. You can also increase air turnover in your house by opening up the windows. When they leave, you can wipe down any door handles, surfaces they interacted with. Similarly, if you are having a responsible, social distancing party in your backyard with a few people and someone needs to use the bathroom, you can let them use it. However, make sure there is a clear path to the bathroom. Set out paper towels for them to dry their hands with. Ask them to use paper towels when they touch surfaces, like the tap etc. You can also wipe down surfaces after then have finished.

My partner or roommate and I both tested positive. Do we need to isolate from each other?

After a suspected or confirmed infection, the CDC has formal guidelines establishing when it is safe for someone who has recovered from infection to leave isolation.

If you had symptoms that you think or you know you had COVID-19, you can be around other people and leave your isolation after it’s been at least ten days since your symptoms appeared and you have 3 days with no fever and an improvement in symptoms. If you can get tested, you can exit your isolation after two consecutive negative tests at least 24 hours apart, no fever, and improved symptoms.

If you tested positive for COVID-19 but you did not have any symptoms, you can be with others 10 days after you tested positive or after two consecutive negative tests at least 24 hours apart.

Just because you and your partner or roommate are both infected with the same virus does not mean you should consider interacting during any time when either of you could be infectious. Check back in the with the CDC periodically for updates to these guidelines.

Is grocery shopping safe for the elderly?

For the past few months, a lot of individuals over 60 have been able to have their shopping done for them, either by family members, neighbors, or delivery services. But if that is no longer an option, there are safe ways for senior citizens to go to grocery stores.

First, check to see if local stores have specific “senior hours” set aside for grocery shopping. These are times when people under a certain age are not allowed to enter the store, the total number of customers allowed inside is very low, and they are often first thing in the morning when the store opens, right after it is cleaned thoroughly. If that is an option, seniors should absolutely take advantage of it if they are able to.

Second, take all precautions: wear a clean mask and don't touch it once it’s on and in place, use hand sanitizer frequently (many stores have dispensers placed throughout), be very conscious of maintaining physical distancing, avoid face to face interactions entirely, and definitely no face-touching. Try to follow a ‘clean hand, dirty hand’ approach. If you run into someone you know, don’t forget that we’re in a pandemic – please don’t stop and strike up a conversation. Wave and keep moving, indicate that you’ll call them later if you want to chat.

Third, stock up with about two weeks of supplies to reduce the frequency of trips.

As soon as you get home, wash your hands. Then remove your mask and wash your hands again. Put all your groceries away and then wash your hands again.

Can teachers wear only a face shield without a mask while teaching?

Instructors and teachers should not consider wearing only a face shield in a return to in-person instruction. To be used correctly, face shields should be coupled with face masks. Face masks that cover the nose and mouth are protective for the people around you. These can be anything from reusable fabric masks to medical-grade PPE. These kinds of masks reduce the likelihood that your respiratory droplets will reach another person and potentially infect them. Face shields are clear plastic that do not effectively prevent your respiratory droplets from reaching others. They are open at the bottom and on the sides, allowing space for respiratory droplets to reach others.

Face shields are generally used when there is danger of viral infection into the eyes or elsewhere on the face or a danger of splatter, which could penetrate or absorb into a fabric or surgical mask. In these cases, they are an additional layer of PPE that are always used WITH masks.

In an indoor classroom setting when a teacher is likely to be speaking and projecting their voice, a mask is absolutely necessary. Wearing a shield in addition to a mask is optional. Additional recommendations for educators may vary by institution but the CDC guidelines to wear a mask in public should definitely be applied to classroom settings.

Why is wearing a cloth mask over your mouth only not sufficient?

When wearing a cloth mask, it is important to wear it over both your mouth and your nose. Virus particles can be expelled via the mouth when coughing, talking, singing, etc. They can also be expelled via the nose when sneezing or just breathing. Wearing a mask just over the mouth is therefore not effective in reducing your potential for infecting others with virus. If you see people with a mask down over their nose in public, you might politely let them know that “their mask seems to have fallen down from their nose.”

Why should masks cover your nose?

We’re seeing increased mask wearing, which is great, but we’re also seeing some improper mask wearing. The primary purpose of a mask is to prevent your respiratory droplets from traveling to other people. Those droplets come from your nose and mouth so your mask should cover both of these areas and the perimeter of the mask should maintain tight contact with your face. Remember, one of the ways samples are collected for diagnostic lab tests is by nasal swabs, which means the virus is present in the nasal cavity of infected individuals. An interesting recent study detailed how a pair of hair stylists that had both had symptomatic COVID-19 together interacted with 139 clients. One of the stylists infected members of her family in the home environment. In the salon, all clients and the stylists were wearing masks. Reassuringly, not one of the clients exhibited COVID-19 symptoms and 67 of whom regardless sought out a test were negative for virus.

Can I take my mask off when I sneeze?

Activities like sneezing and coughing are the highest risk events for spreading SARS-CoV-2. We know that an uncovered cough or a sneeze can spray virus containing droplets into the air over 8 feet or more. We also have growing concern that the virus can remain in the air for long periods, particularly indoors. If you are feeling unwell, with sneezing and coughing the best place for you is at home, isolated from others. If you are just worried about the occasional cough or sneeze that could still spread virus if you are an symptomatic carrier, you should wear the mask despite it being unpleasant for the wearer. You might like to keep an extra cloth or disposable mask in case yours becomes wet/soiled. As a reminder, cotton masks should be washed out at the end of the day before reuse. If you are outdoors and need to sneeze and you can get far away from people, it should be safe to remove your mask.

Testing and Treatment Questions

Is there a way to know if you already had the virus?

Yes. A number of countries are currently rolling out antibody tests and the phrase ‘immunity passports’ is being used to describe how with a positive antibody test people may be free to go back to work. In the last few days the FDA approved a rapid antibody test that can be used by diagnostic labs to determine in just 2 minutes if someone has antibodies in their blood. As an important note, it can take several weeks to make strong antibodies. Once these tests are broadly available people will need to wait for several weeks after getting sick so that their results are accurate. These tests will initially be carried out on people who tested positive with a COVID-19 diagnostic test to make sure the antibody tests are accurate.

What is known about the various treatments?

There are no known or approved effective treatments for COVID-19. Recently, the World Health Organization launched a set of multi country global trials on 4 sets of drugs to compare the severity of disease and survival of people on the drugs vs those not. One drug that has been controversial, chloroquine, has been included in these studies. The scientific community is urging caution as the original study showing potential efficacy of chloroquine + an antibiotic was based on a very few number of patients. Many of those patients were lost out of the study into the ICU, meaning they did indeed end up having severe disease, a fact not captured in the data. The FDA has not approved the use of chloroquine for COVID-19. In the coming weeks, the WHO led global studies should provide some information about treatment options. In the meantime, people taking chloroquine without evidence of efficacy are putting themselves at risk of side effects and limiting the ability for patients who take the drug for other conditions like lupus from accessing it.

How do coronavirus tests work?

You’ve all heard that the process involves collecting a sample using a nasal swab. But what happens after that? A thin swab is inserted into a patient’s nasal passage for a few seconds. It absorbs the secretions from the surrounding tissue. We use that swab to look for the virus’s genetic material. While our genetic material is stored as DNA, this virus RNA. To look for viral RNA in the sample, we first remove everything else from the sample. Proteins and fats are chemically destroyed so you’re left with only RNA. That includes RNA from the host, maybe the coronavirus, and maybe other viruses. The standard CDC and WHO tests use a process called reverse transcriptase polymerase chain reaction, or RT-PCR. The first step is reverse transcription, where the RNA is used to produce DNA. Then you add a fragment of DNA that is complimentary to a target segment of DNA for the virus. If the virus is present, the fragments will bind to the target portion of the viral DNA. The exact target varies between tests, but process is the same.

Then the DNA is amplified through a polymerase chain reaction, or PCR, which cycles through temperatures that trigger chemical reactions that copy the viral DNA. The DNA doubles in quantity with every cycle so if you started with any, you may have billions of copies of it by the end of just 35 cycles. At the end of this amplification stage, you measure how much DNA is in the sample. A negative result means there was no detectable DNA found at the end of the thermocycles. A positive result means the targeted DNA was detected.

But remember, no test is perfect. False negative results can occur if the sample is collected or transported incorrectly. They can also occur if the patient simply isn’t shedding a lot of virus at the time of sample collection. False positives can occur from sample contamination or by targeting non-unique segments of DNA, which results in the replication of a similar virus but not the target virus. Standardized kits are designed to reduce this error.

After a patient recovers and clears the virus, they will no longer have viral RNA in their nasal secretions and an RTPCR test will come back negative. These tests measure active infections only.

What about errors in serological testing?

Antibody testing tells us how many people were previously infected with a pathogen. Beth gave us a great overview on this in an earlier video and what it might mean for individuals as we look ahead. Antibodies can be detected during infection or afterwards, even if the infection was asymptomatic and the patient never sought testing or treatment while they were infected.

An advantage of these tests is that they can tell us what’s happening at a population level – for example, what proportion of the population has likely been infected and what proportion is susceptible? Using large numbers of individuals helps overcome the errors of overinterpreting any single test result and the information can help us make public health decisions.

First, serological testing can help us understand the case fatality rate. In a previous video, I explained that the case fatality rate is the number of infections that result in death. I explained we couldn’t accurately calculate that at the moment because we don’t know how many infections there have been and we’re mostly counting severe and symptomatic cases, which tends to overestimate case fatality rates. Serological testing would help us understand the total number of previous cases better than we do now, so we can more accurately calculate the proportion that resulted in fatalities. This same information could help us estimate transmission rates across populations. Which ties in to my next point: Second, serological testing could help us measure exactly how effective behavioral interventions have been. By measuring the differences in serological findings across populations, we can assess behavioral interventions were effective and successful, and try to understand why others might have been less effective. We can use that information to update and adapt the next phase of behavioral interventions.

hile there is a lot of talk about assessing individual immunity to allow the recovered members of society take on critical tasks, we’re not quite there yet with testing accuracy.

The sensitivity of a test describes its ability to correctly identify someone who has had the disease and the specificity refers to a tests ability to correctly identify someone who has NOT had the disease. A false negative from a test with low sensitivity would be misleading, but a false positive from a test with low specificity could cost many lives. This could happen due to cross reactivity with other viruses, which is particularly important because we know other coronaviruses frequently circulate through our populations.

Ideally we would like the sensitivity and specificity of the serological tests to be near 99%, which means that tests should return only about 1 false positive and 1 false negative for every 100 true positive and true negative results.

If we know a test has a specificity of 85%, for example, we can estimate a range of immunity for a population across thousands of samples. That can tell us how many cases to prepare for in the coming months and when to ease restrictions. However, we can’t use a test with 85% specificity to clear a single individual for high risk activities without endangering a lot of lives. The currently available tests need improvement in both sensitivity and specificity before we can use them confidently to assess individual infections.

So while serological tests may not yet be accurate enough for us to make decisions about individuals, they can tell us a lot of important information about populations and making population level health policy.

Has there been any information about long-term health effects from having had the virus?

As we look ahead to understanding the long term health effects in people following recovery from COVID-19, we can really only go back as far as the earliest human infections – which happened around December of 2019. We don’t know what this infection means for long term recovery with regards to tissue damage, from mild to severe cases. We know that recovery from any serious illness or stay in intensive care can be difficult. Make sure you follow guidelines for physical and emotional recovery and don't expect recovering individuals to bounce right back.

The other important unknown about long term effects following infection have to do with immunity. How long does immunity last and how strong is it? Scientists have detected antibodies in experimental animals that have recovered from the virus. Moving forward to understanding what that means for humans, we’ll have to test for antibodies, which Beth described in a previous AskCIDD video.

Can pooling samples speed up testing?

Pooled sample testing is an efficient and widely used strategy to test for an infectious disease in a large number of samples. Pooling samples means testing facilities combine a small amount of a sample from many samples, combine them, and then run the test to look for the virus across that combined, or pooled, sample. If a pooled sample tests positive, then sub-pools or individual samples are tested to identify the positive individual samples. If a pooled test returns a negative result, then all individual samples in that pool are negative. This is known as ‘Dorfman testing’ and it is the most widely used form of pooled testing. This strategy is particularly effective if prevalence and transmission of the disease are low in the population.

Pooled sample testing allows testing facilities to process large numbers of samples rapidly. The are three big advantages of this approach:

  • First more samples can be processed in a short amount of time
  • Second, this strategy reduces the total number of tests that need to be done
  • Third, pooling samples reduces use of limited reagents, which are difficult to source when demand is high, like it is right now.

A study from Germany showed that pooling anywhere from 4 to 30 samples was an efficient strategy to detect SARS-Coronavirus-2 without sacrificing test sensitivity. This means they didn’t miss any positive samples in these pooled tests. Each testing facility can determine the optimal number of samples they should pool based on the sensitivity of their tests.

Pooling samples to efficiently and effectively screen a high volume of clinical samples for infectious diseases has been done for a long time. A return to basic operations for most counties and states will require a massive amount of testing because we’ll need to test asymptomatic individuals in addition to symptomatic individuals. Saving costs and time per individual test could help strategic efforts to ramp up testing.

Remdesivir is an antiviral that was first developed to use against Ebola virus. This last week, the first data from a double-blind, randomized, placebo-controlled study for use of Remdesivir against COVID-19 was published in the New England Journal of Medicine. Over 1,000 people testing positive for COVID-19 with lower respiratory symptoms were given either the drug or a placebo and followed to examine their recovery. In a double-blind study like this, the doctors/researchers are also not aware who was given the actual drug to prevent any bias in evaluating patient recovery. The study showed that those given the drug recovered on average after 11 days vs those given the placebo who recovering after 15 days. Severe disease was seen in 21 percent of patients on the drug and 27 percent of patients taking the placebo. Death rates were also slightly lower for those on Remdesivir, 7 percent vs 11 percent for the placebo. This study therefore shows some improvement in severity, death rate and duration of disease for people taking the drug. It is not however an instant cure. Additional studies may yield further information on dosing strategies and use in different types of patients.

Pooling samples for testing – is anyone actually doing this? Why or why not?

In a previous week, we explained that pooling samples is an efficient way to test a lot of samples at once and it can be particularly effective when prevalence is low. This strategy allows researchers to rapidly and cheaply test a lot of samples. In the US, pooled testing is often used in testing for a number of sexually transmitted infections and when screening blood donations for diseases.

So are people actually doing this during the current COVID-19 pandemic? Yes and no. Pooling samples helped diagnostic labs in Wuhan, China rapidly scale up the number of tests they could process per day.

For COVID-19 diagnostic testing in the US, all protocols or changes to protocols must be approved by the FDA. Pooling samples is a change to the standard protocol. Some labs and some tests are approved for pooled testing under an emergency use authorization. So the technical answer is yes, in the US testing pooled samples has begun in a few provisional labs but it’s not yet being done widely.

I got a negative antibody test, could I still have had COVID-19?

Unfortunately, the answer is yes, for several reasons. First, we know that if you take the antibody test too early after getting sick, your body won’t have had sufficient time to have made antibodies. It is recommended that you wait several weeks after falling ill before getting an antibody test. A recent study has also revealed that people who have asymptomatic cases of COVID-19 only continue to produce antibodies for a short period of time. So, it could be that your infection was not strong enough to trigger a lasting antibody response. Third, there are many versions of antibody tests being used, many of them appear to perform very poorly. We know this because we see high rates of negative results even when we test patients that previously had COVID-19 symptoms and that tested positive by PCR for the virus. This failure is likely the result of real underlying biology, ie declining antibody loads in patients, as well as technical issues around the sensitivity of the test itself.

Can tests tell if someone is infectious?

Unfortunately, tests cannot definitively tell you if you’re infectious, or capable of transmitting the virus. Serology tests, or antibody tests, can tell you if you’ve likely been infected and had an immune response. Diagnostic tests can tell if you’re likely to be currently infected by looking for the presence of virus in your mucosal membranes. If a diagnostic test results returns positive OR you are symptomatic, it is safe to assume that you are infectious.

However, neither serology nor diagnostic tests are perfect, and they cannot tell you whether you are actively infectious or not. Due to testing errors and detection thresholds, it is technically possible to test negative for both of these tests and still be infected and infectious. The best advice is to continue to act cautiously and protect others from you, as if you are infected and infectious.

Can people be given drugs to boost their immune systems?

This is an area that needs further study. First, there are very few ways to broadly boost immunity. Second, we still have a poor understanding of what happens to the immune system during COVID. While it might make sense to boost immunity early on in the course of infection or in immunocompromised people, it could cause problems later on as by-products of the inflammatory response are thought to be the cause of COVID-19’s severity. This late inflammation has been called the ‘cytokine storm.’ Some researchers and doctors, however, are skeptical of such a storm, believing instead that early inflammation gives way to exhausted and non-functional T cells (immunity cells) late in the infection that have become over-run with virus. Multiple studies are underway to try to understand immunity during COVID and whether either boosting or reducing the immune response would be a good idea. A number of drugs are also being trialed. Steroids, already standard COVID treatment, reduce inflammation broadly, but more surgical approaches targeted at reducing cellular uptake of key players like interleukin 6 are also being explored. Examples of potential immune boosters include interleukin-7 that improves T-Cell proliferation and granulocyte-macrophage colony stimulating factor (GM-CSF) currently given to patients post bone marrow transplant to help rebuild their immunity. Last, many of these drugs are also being studied in combination with antiviral therapeutics like interferon.

What does it mean to test positive for virus many weeks later?

We know that a small proportion of people may continue to test positive for SARS-CoV-2 long after they have recovered, sometimes after previously testing negative. The latter may relate to the sensitivity of the diagnostic test or the luck of whether virus, rare in the body, is captured in the sample. The good news, coming from research in South Korea, suggests that these recovered, but positive testing people, are not likely to be contagious.

Why is rapid turnaround on testing important?

It’s important to have rapid turnaround on COVID-19 tests because tests results trigger actions that are critical to outbreak management. First, it’s important for each person to know whether they are infected or not. If they’re not infected, finding out quickly will minimize the disruption to their lives and stress levels. If they are infected, they can proceed with isolation, which protects the people around them, and symptom monitoring to manage their case. Second, a positive test result will result in contact tracing to identify and notify their contacts who may have been exposed. The faster those people can be informed, quarantined, and tested, the fewer people they will potentially expose to the virus. This is currently the only way to get ahead of chains of transmission. Longer turnaround times for test results mean that infected people and their contacts can be unknowingly transmitting the virus for several additional days. In some cases, we’re seeing test results returned several days or a week after samples were collected, which almost too long to be actionable. Ideally, results would be available in a matter of hours but receiving test results even within a day or two would significantly help reduce transmission.

Illness-Related Questions

Does blood type affect COVID-19 severity?

There are now a couple of studies showing a potential link between blood type and COVID severity. First, a study in China revealed that people of blood type A were more likely to have severe COVID as measured by a 50% greater need for oxygen or a ventilator. More recently, another study sequenced the genomes of people with COVID and looked for associations between differences in their DNA and their severity. Two regions of the human genome seemed to be predictive- each containing multiple genes. Further studies will be needed to narrow down exactly which of the genes in these two regions matter. In one of those regions, however, sits the gene that encodes blood type. Some of the other suspect genes across these two regions include a gene that controls massive upregulation of the immune response. This would make sense, since part of COVID severity relates to an overly active immune response rather than damage from the virus itself. Another candidate gene encodes a protein that interacts with the receptor for the SARS-CoV-2 spike protein and controls entry of the virus into cells.

Does past SARS infection make Covid less severe?

A recent study has demonstrated that people who had SARS still have antibodies over a decade later. This would suggest that IF there the antibodies for SARS cross reacted with SARS-CoV-2 that these people might have some protection against SARS-CoV-2. Remember that only around 8,000 people had SARS, many of whom may have passed away by now. It will take time to track down remaining patients and see if they have had COVID-19. If there was protection – not many people would have it. If you asked a virologist, they would say that it is unlikely that there will be cross protection between SARS and SARS-CoV-2 given how different their genomes are. All of the mutations that have accumulated that make these viruses different from one another mean that the proteins found on the virus surface, that our bodies recognize and make antibodies against, will also be different. Another set of related viruses that are more interesting, given their high prevalence in humans, is the coronaviruses that cause the common cold. If past infection with these viruses provided some cross immune protection, then more people are likely to benefit. Unfortunately, the coronaviruses that cause the common cold have been poorly studied, largely because the symptoms they cause are so mild. We do not know enough about them yet to know whether they offer cross protection for COVID.


The hard surfaces made for coronavirus

The primary way people become infected with the coronavirus is from person-to-person transmission. This close contact in the form of a hug, handshake, or being in a packed public space enables infected individuals to easily spread their respiratory droplets, which are typically sneezed or coughed.

But because respiratory droplets are heavy, they typically fall to the ground easily. Depending on where they land, they could persist on a surface before being touched by a hand that carries the virus to a nose or mouth, leading to infection. (Learn how these underlying conditions make coronavirus more severe.)

On surfaces, they found SARS-CoV-2 lasted for 24 hours on cardboard, two days on stainless steel, and three days on a type of hard plastic called polypropylene.

All viruses are bits of genetic code bundled inside a collection of lipids and proteins, which can include a fat-based casing known as a viral envelope. Destroying an enveloped virus takes less effort than their non-enveloped compatriots, such as the stomach-busting norovirus, which can last for months on a surface. Enveloped viruses typically survive outside of a body for only a matter of days and are considered among the easiest to kill, because once their fragile exterior is broken down, they begin to degrade.

Yet every enveloped virus is different, and scientists around the world are aggressively researching SARS-CoV-2, the official name of the new coronavirus, to understand how it stacks up. A study published Tuesday in the New England Journal of Medicine looked at how long it can be detected on various materials. Dylan Morris, an evolutionary biologist at Princeton University and a study co-author, says the mission was to investigate which surfaces found in medical settings might serve as a potential cesspool for infecting patients.

On surfaces, they found SARS-CoV-2 lasted for 24 hours on cardboard, two days on stainless steel, and three days on a type of hard plastic called polypropylene. The virus could only be detected for four hours on copper, a material that naturally breaks down bacteria and viruses. The study also revealed the novel coronavirus and its cousin SARS, which caused a major outbreak in 2002 and 2003, last on surfaces for similar amounts of time. (Find out how coronavirus spreads on a plane—and the safest place to sit.)

People ordering goods online to avoid crowds may conceivably come into contact with contaminated cardboard, though the U.S. Centers for Disease Control and Prevention emphasizes that surfaces are not thought to be the primary way the virus is transmitted.

Morris doesn’t want to speculate too much on everyday surfaces, but his general advice would be to carefully wash items and one’s own hands.

But their study has limitations. The team examined the virus in a highly controlled lab setting. Spaces that are commonly touched, like a stair rail or bus pole, would contain a higher amount of the virus and present a greater risk for infection. Environmental conditions can also influence how long the virus lasts. Humidity, for example, is thought to make it harder for respiratory droplets to travel through the air, and ultraviolet light is known to degrade viruses. (Will warming spring temperatures slow the coronavirus outbreak?)

The study also found the novel coronavirus could persist as aerosols—tiny airborne particles—for up to three hours, though Morris clarifies larger respiratory droplets are more likely to be infectious. Viral aerosols are primarily a concern in clinical settings where certain treatments like ventilation can produce these particles. It is unlikely that these coronavirus aerosols come into play in open-air settings or public places like supermarkets.


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The Delta variant is the B.1.617.2 strain of coronavirus first identified in India that’s now spreading around the world.

“This variant is even more transmissible than the UK variant, which was more transmissible than the version of the virus we were dealing with last year,” US Surgeon General Dr. Vivek Murthy said.

In addition to increased transmissibility, “it may be associated with an increased disease severity, such as hospitalization risk,” said Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases.

An analysis of 38,805 sequenced cases in England showed the Delta variant carried 2.61 times the risk of hospitalization within 14 days compared with the Alpha variant, when variables such as age, sex, ethnicity and vaccination status were taken into consideration.

Researchers believe the Delta variant has taken over as the dominant strain of coronavirus in the UK.

“We don’t want to let happen in the United States what is happening currently in the UK, where you have a troublesome variant essentially taking over as the dominant variant,” Fauci said.

But it’s happened before. The Alpha (B.1.1.7) variant, first detected in the UK, is “stickier” and more contagious than the original strain of novel coronavirus. It used to be the dominant variant in the UK and is now the dominant strain in the US.

The two-dose vaccines from Pfizer/BioNTech and AstraZeneca have shown to be effective in protecting against the Delta variant — but the protection requires getting both doses, said Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases.

“There is reduced vaccine effectiveness in the one dose. Three weeks after one dose, both vaccines, the (AstraZeneca) and the Pfizer/BioNTech, were only 33% effective against symptomatic disease from Delta,” he said.

“If you had your first dose, make sure you get that second dose. And for those who have been not vaccinated yet, please get vaccinated.”

Lab experiments described in a recent preprint study also suggest the Moderna vaccine, as well as the Pfizer/BioNTech vaccine, will offer protection against the Delta variant — though more study is needed.

Johnson & Johnson says it’s gathering data on its vaccine and emerging variants.

The Delta variant is more transmissible than both the original strain of novel coronavirus and the Alpha (B.1.1.7) strain that’s currently dominant in the US, Surgeon General Dr. Vivek Murthy said.

“It’s yet another reason to get vaccinated quickly,” he said.

Now that all three vaccines authorized for use in the US have shown to be highly effective and safe in adults, one vaccine is already available for children ages 12 and up. And clinical trials are underway for younger children.

Pfizer/BioNTech’s vaccine is currently authorized for people ages 12 and up. Vaccine trial data for children as young as 5 could be available by the end of this year.

Johnson & Johnson said its vaccine, which is currently authorized for adults, could be available to children by September. “We will conduct several immunogenicity and safety studies in children from 17 years of age down to neonates,” said Dr. Macaya Douoguih, head of clinical development & medical affairs with J&J’s vaccine arm Janssen.

Moderna’s vaccine is currently authorized for people ages 18 and older. In late May, Moderna said early trial data shows the vaccine is safe and appears to be effective in 12- to 17-year-olds. On June 10, the company said it has asked the US Food and Drug Administration to authorize the vaccine for the adolescent age group.

As for elementary age children, vaccines might not be authorized for that age group until the end of 2021, said Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases.

“Kids can transmit the virus. They are susceptible to it,” said Anne Rimoin, an epidemiology professor at UCLA.

In Florida, for example, the number of children who had been hospitalized with Covid-19 surged 23% in eight days last summer – from 246 on July 16 to 303 on July 24.

While children are far less likely to die from coronavirus than adults, studies show kids can contract and spread coronavirus:

– A study out of South Korea shows children at least 10 years old can transmit Covid-19 within a household just as much as adults can.

– In the US, a CDC study showed more than half of the children ages 6 to 10 who attended Georgia summer camp in June and got tested for Covid-19 tested positive.

The study – which examined test results following a camp that more than 600 campers 120 staffers attended – found that 51% of those ages 6 to 10 tested positive 44% of those ages 11 to 17 tested positive and 33% of those ages 18 to 21 tested positive.

“This investigation adds to the body of evidence demonstrating that children of all ages are susceptible to SARS-CoV-2 infection and, contrary to early reports, might play an important role in transmission,” wrote the CDC study’s authors.

“It is a normal human reaction to be afraid,” pediatrician Dr. Edith Bracho-Sanchez said. “They’re having a normal reaction, and perhaps they haven’t been able to sit down with their physician.”

She suggests finding a time to have a calm, rational conversation — when neither person is angry or likely to start a fight.

“The first thing I would say is ‘I get it. I totally get where you’re coming from and I understand that you’re concerned about this,’” Bracho-Sanchez said.

It’s not clear if or when vaccine booster shots might be needed, CDC Director Dr. Rochelle Walensky said in late May.

Research shows the Pfizer/BioNTech and Moderna vaccines stay highly effective for at least six months (and counting).

But it’s not clear how long the protection provided by vaccines will last.

“We don’t know if it’s a year. We don’t know if it’s nine months. We don’t know if it’s two years yet,” board-certified internist Dr. Jorge Rodriguez said.

“Obviously, the people that were in the (vaccine trial) studies that started in October or so, they’re being followed on a regular basis” to help determine how long vaccine immunity lasts, Rodriguez said.

“Delay travel until you are fully vaccinated,” the CDC says. Fully vaccinated means at least 2 weeks have passed since your last dose of Covid-19 vaccine.

For those traveling within the US, you “do NOT need to get tested or self-quarantine if you are fully vaccinated or have recovered from COVID-19 in the past 3 months. You should still follow all other travel recommendations,” the CDC says.

Americans traveling internationally should learn about the Covid-19 restrictions at their destination. Those flying back home to the US must provide proof that they have recently tested negative for coronavirus or recently recovered from Covid-19. They should also get a viral test 3 to 5 days after coming home, the CDC says.

For those who aren’t fully vaccinated but must travel, the guidelines are much tougher. The CDC says it’s important to wear a mask get tested within three days before traveling maintain physical distance from anyone not traveling with you and quarantine for 10 days after you return home. (That quarantine period can be reduced to 7 days if you get tested 3 to 5 days after coming home.)

“Fully vaccinated people can resume activities without wearing a mask or physically distancing, except where required by federal, state, local, tribal, or territorial laws, rules, and regulations, including local business and workplace guidance,” the CDC says.

But those who aren’t vaccinated should keep wearing masks in public places (especially indoors) and when it might be hard to keep distance from people who don’t live with you.

“It’s estimated that about 70% of Americans must be vaccinated before we get to herd immunity through vaccination. That’s the point where enough people have the immune protection that the virus won’t spread anymore,” said emergency medicine physician Dr. Leana Wen, a visiting professor at George Washington University Milken Institute School of Public Health.

“This means about 230 million Americans must receive the vaccine … At that point, we could probably see one another without masks — but not before.”

As of June 9, only about 140 million Americans — or about 42.5% of the US population — had been fully vaccinated, according to CDC data.

“Yes, you should be vaccinated regardless of whether you already had COVID-19,” the CDC says.

“That’s because experts do not yet know how long you are protected from getting sick again after recovering from COVID-19.”

“There are actually six other coronaviruses – MERS and SARS and four other viruses that create the common cold. They don’t seem to do very well at creating long-term immunity,” epidemiologist Dr. Larry Brilliant said.

“Many of the vaccines that we’ve made in history are actually stronger than the virus is itself at creating immunity.”

It’s literally impossible to get Covid-19 from any of the vaccines used in the US because none of them contains even a piece of actual coronavirus.

Both the Pfizer/BioNTech and Moderna vaccines give about 95% protection against symptomatic Covid-19, and both are virtually 100% effective against severe Covid-19 illness. In their clinical trials, no one who was vaccinated died from Covid-19.

The Johnson & Johnson vaccine was 72% effective against Covid-19 among US trial participants and 85% effective against severe Covid-19. Like the other two vaccines, no one who was vaccinated during the clinical trial died from Covid-19.

But Johnson & Johnson’s vaccine was tested later – when coronavirus cases were surging and new variant strains were spreading more widely.

And unlike the Moderna and Pfizer/BioNTech vaccines, which require two doses, the Johnson & Johnson vaccine requires only one dose.

It’s too early to tell, the US Food and Drug Administration says.

The three vaccines currently used in the US were developed less than a year after Covid-19 was first detected in the US. The FDA said emergency authorization was swift, but it did not come at the cost of safety.

But since all Covid-19 vaccines are relatively new, it’s not clear exactly how long immunity from the vaccines will last.

“It may be that coronavirus vaccine becomes something that you have to get every year, like the flu vaccine,” emergency physician Dr. Leana Wen said.

Others say it’s possible you could go much longer without needing another Covid-19 vaccine — especially if enough people get vaccinated right now.

“The vaccine elicits such high levels of antibodies that even when confronted with a variant … there’s still meaningful protection,” said Dr. Scott Hensley, an immunologist at the University of Pennsylvania who has studied mRNA vaccines like Pfizer’s and Moderna’s for years.

“These mRNA vaccines – it really seems the level of antibodies they elicit are so high, they are persistent … I would not be surprised if this is a vaccine that we only get once.”

Vaccine trial participants are still being closely monitored. The Pfizer/BioNTech vaccine remains more than 91% effective against symptomatic Covid-19 for at least six months, the companies said. They said the vaccine also appeared to be fully effective against the worrying B.1.351 variant of the virus, which researchers feared had evolved to evade the protection of vaccines.

Research is still evolving, but a recent study examining antibodies suggests you could be immune for months after infection.

“Although this cannot provide conclusive evidence that these antibody responses protect from reinfection, we believe it is very likely that they will decrease the odds ratio of reinfection,” researchers from Mount Sinai wrote.

“It is still unclear if infection with SARS-CoV-2 [the scientific name for the novel coronavirus] in humans protects from reinfection and for how long.”

There have been some reports of people getting infected twice within several months. Doctors said a 25-year-old Nevada man appeared to be the first documented case of Covid-19 reinfection in the US. He was first diagnosed in April 2020, then recovered and tested negative twice. About a month later, he tested positive again.

A separate team of researchers said a 33-year-old man living in Hong Kong had Covid-19 twice, in March and August of 2020.

Last year, an 89-year-old Dutch woman – who also had a rare white blood cell cancer – died after catching Covid-19 twice, experts said. She became the first known person to die after getting reinfected.

But if you don’t get a vaccine, the consequences will extend far beyond yourself — even if you’re young and healthy now. Not only would you be more vulnerable to getting severely sick with Covid-19 or “long Covid” — it will also be harder to achieve herd immunity through vaccination.

In other words: Getting a vaccine is critical for slowing or possibly ending this pandemic. And that will help everyone get back to normal, faster.

If only half of all Americans are willing to get vaccinated, Covid-19 could stick around for years, said Dr. Francis Collins, director of the National Institutes of Health.

“It’s all free. The government is paying for this,” said Dr. Paul Offit, director of the Vaccine Education Center at the Children’s Hospital in Philadelphia.

There’s growing evidence suggesting vaccines could also help prevent you from spreading coronavirus. But the CDC says there’s not enough data yet to prove whether vaccinated people could still carry the virus and infect others.

Moderna said its vaccine may be able to prevent infection and transmission.

“What Moderna did … is they took some extra samples, or test swabs, from the subject in the clinical trial between the first and second dose of vaccine. Remember, they give you two doses, and after four weeks they get that second dose of vaccine,” said Dr. Rick Bright, former head of the Biomedical Advanced Research and Development Authority.

“They looked at these samples, and they found out that more people who received the placebo dose got infected from the coronavirus than the people who get the vaccine dose. That means the first dose of vaccine actually could be offering some level of protection against infection – not just protection from severe illness,” he said.

“So if this plays out in a larger study, in a larger analysis, it could be very compelling to show that these vaccines could have impact over this protection of infection.”

(But you should not skip your second dose of a two-dose vaccine. Here’s why.)

A study from the UK suggests the Oxford/AstraZeneca vaccine, which has not yet been authorized for use in the US, might also help slow the spread of coronavirus. Researchers measured transmission by swabbing some participants for the virus every week. They found that the rate of positive tests declined by about half after two doses of the vaccine.

The FDA said it’s not yet clear whether the Pfizer/BioNTech vaccine prevents people from infecting others.

“Most vaccines that protect from viral illnesses also reduce transmission of the virus that causes the disease by those who are vaccinated,” the FDA said. “While it is hoped this will be the case, the scientific community does not yet know if the Pfizer/BioNTech COVID-19 Vaccine will reduce such transmission.”

Some people have reported feeling temporary, flu-like symptoms. Don’t freak out if this happens to you, health experts say.

“These are immune responses, so if you feel something after vaccination, you should expect to feel that,” said Patricia Stinchfield of Children’s Hospitals and Clinics of Minnesota.

“And when you do, it’s normal that you have some arm soreness or some fatigue or some body aches or even some fever,” Stinchfield said.

Read more about what to do if you do get side effects and why side effects are often a good sign.

The Pfizer/BioNTech vaccine has shown no serious safety concerns, Pfizer said. Pfizer has said side effects “such as fever, fatigue and chills” have been “generally mild to moderate” and lasted one to two days.

Moderna said its vaccine did not have any serious side effects. It said a small percentage of trial participants had symptoms such as body aches and headaches.

With the Johnson & Johnson vaccine, the most common side effects were pain at the injection site, headache, fatigue and muscle pain. While the CDC recommends the Johnson & Johnson vaccine, “women younger than 50 years old especially should be aware of the rare but increased risk of thrombosis with thrombocytopenia syndrome (TTS),” the agency says. “TTS is a serious condition that involves blood clots with low platelets. There are other COVID-19 vaccine options available for which this risk has not been seen.”

Some Covid-19 survivors have reported problems weeks or months after testing positive.

  • In the 18-to-34 age group, 26% said they still had symptoms weeks later.
  • In the 35-to-49 age range, 32% were still grappling with the effects weeks later.
  • For those 50 and older, 47% said they still had symptoms weeks later.

And the risk of death from coronavirus-related heart damage seems to be far greater than previously thought, the American Heart Association said.

Inflammation of the vascular system and injury to the heart occur in 20% to 30% of hospitalized Covid-19 patients and contribute to 40% of deaths, the AHA said. AHA President Dr. Mitchell Elkind said cardiac complications of Covid-19 could linger after recovering from coronavirus.

Aerosolized spread is the potential for coronavirus to spread not just by respiratory droplets, but by even smaller particles called aerosols that can float in the air longer than droplets and can spread farther than 6 feet.

Respiratory aerosols and droplets are released when someone talks, breaths, sings, sneezes or coughs. But the main difference is size.

“If you have droplets that come out of a person, they generally go down within 6 feet,” said Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases.

But aerosols (aka droplet nuclei) are smaller – less than 5 microns in diameter, according to the World Health Organization.

“Aerosol means the droplets don’t drop immediately,” Fauci said. “They hang around for a period of time.”

This becomes “very relevant” when you are indoors and there is poor ventilation, he said.

Multiple case studies suggest coronavirus can spread well beyond 6 feet through airborne transmission, such as during choir practices, said Dr. Amy Compton-Phillips, chief clinical officer of Providence Health System.

In Washington state, for example, 53 members of a choir fell sick and two people died after one member attended rehearsals and later tested positive for Covid-19.

In July, 239 scientists backed a letter urging public health agencies to recognize the potential for aerosolized spread.

“There is significant potential for inhalation exposure to viruses in microscopic respiratory droplets (microdroplets) at short to medium distances (up to several meters, or room scale), and we are advocating for the use of preventive measures to mitigate this route of airborne transmission,” the letter said.

The Crisis Text Line is available texting to 741741. Trained volunteers and crisis counselors are staffed 24/7, and the service is free.

The Substance Abuse and Mental Health Services Administration Disaster Distress Helpline provides 24/7, 365-day-a-year crisis counseling and support to people experiencing emotional distress related to disasters. Call 1-800-985-5990 or text TalkWithUs to 66746 to connect with a trained crisis counselor.

For health care professionals and essential workers, For the Frontlines offers free 24/7 crisis counseling and support for workers dealing with stress, anxiety, fear or isolation related to coronavirus.

“You can certainly get both the flu and Covid-19 at the same time, which could be catastrophic to your immune system,” said Dr. Adrian Burrowes, a family medicine physician in Florida.

In fact, getting infected with one can make you more vulnerable to getting sick with the other, epidemiologist Dr. Seema Yasmin said.

“Once you get infected with the flu and some other respiratory viruses, it weakens your body,” she said. “Your defenses go down, and it makes you vulnerable to getting a second infection on top of that.”

On their own, both Covid-19 and the flu can attack the lungs, potentially causing pneumonia, fluid in the lungs or respiratory failure, the Centers for Disease Control and Prevention said.

“The two (illnesses) together definitely could be more injurious to the lungs and cause more respiratory failure,” said Dr. Michael Matthay, a professor of medicine at the University of California, San Francisco.

And just like with Covid-19, even young, healthy people can die from the flu.

Doctors say the easiest way to help avoid a flu/Covid-19 double whammy is to get vaccinated.

Both the flu and Covid-19 can give you a fever, cough, shortness of breath, fatigue, sore throat, body aches and a runny or stuffy nose, the CDC said.

“Some people may have vomiting and diarrhea, though this is more common in children than adults,” the CDC said.

So the best way to know if you have the novel coronavirus or the flu (or both) is to get tested. The CDC has created a test that will check for both viruses, to be used at CDC-supported public health labs.

More than 40% of US adults have at least one underlying condition that can put them at higher risk of severe complications, according to the CDC.

Covid-19 patients with pre-existing conditions — regardless of their age — are 6 times more likely to hospitalized and 12 times more likely to die from the disease than those who had no pre-existing conditions, CNN Chief Medical Correspondent Dr. Sanjay Gupta said.

While young, healthy people are less likely to die from Covid-19, many are suffering long-term effects from the disease.

Unvaccinated people from different households in a car should wear face masks, said Dr. Aaron Hamilton of the Cleveland Clinic.

“You should also wear one if you’re rolling down your window to interact with someone at a drive-thru or curbside pickup location,” Hamilton said.

It’s also smart to keep the windows open to help ventilate the car and add another layer of safety, said Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases.

If there are tissues nearby, you can take your mask off and sneeze into the tissue before putting your mask back on, CNN Chief Medical Correspondent Dr. Sanjay Gupta said.

For kids in school — or anyone else who might have to wear a mask all day — keep a backup mask in a baggie in case the first mask gets dirty. You can put the dirty mask in the baggie.

It’s also a good idea to keep backup masks in your car in case of any mask accidents.

Coronavirus and Covid-19 are not the same thing, but sometimes the terms can be used interchangeably.

This “novel coronavirus” is novel because it just emerged in humans in late 2019. There have been six other coronaviruses known to infect humans, such as SARS (circa 2003) and MERS (circa 2012).

“Coronaviruses are named for the crown-like spikes on their surface,” or coronas, the CDC says. The scientific name for this novel coronavirus is SARS-CoV-2, which stands for “severe acute respiratory syndrome coronavirus 2.”

Covid-19, however, is the disease caused by the novel coronavirus. The letters and numbers in “Covid-19” come from “Coronavirus disease 2019.”

About 2% to 5% of babies born to mothers with Covid-19 tested positive for coronavirus within the first four days of life, according to the American Academy of Pediatrics.

But infected mothers are unlikely to pass coronavirus to their newborns when appropriate precautions are taken, according to a study published in The Lancet Child & Adolescent Health.

In that study, researchers found no cases of viral transmission among 120 babies born to 116 mothers with coronavirus — even when both shared a room and the mothers breastfed.

But the babies remained 6 feet apart from their mothers, except while breastfeeding. The moms also wore surgical masks when handling their newborns and followed proper hand and breast washing procedures.

That’s not recommended right now, according to the US Organ Procurement and Transplantation Network.

“This guidance may change as more becomes known about the course and treatment of COVID-19,” the network said.

“Donation and transplant clinicians should apply their medical judgment in instances where test results are pending at the time of organ offers.”

Yes, that’s a good idea because cell phones are basically “petri dishes in our pockets” when you think about how many surfaces you touch before touching your phone.

You should regularly disinfect your mobile phone anyway, with or without a coronavirus pandemic.

“There’s probably quite a lot of microorganisms on there, because you’re holding them against your skin, you are handling them all the time, and also you’re speaking into them,” said Mark Fielder, a professor of medical microbiology at Kingston University.

“And speaking does release droplets of water just in normal speech. So it’s likely that a range of microbes – including Covid-19, should you happen to be infected with that virus – might end up on your phone.”

Watch the best ways to disinfect your cell phone here.

There are certainly risks if you’re not vaccinated.

Coronavirus often spreads more easily indoors rather than outdoors — especially if you’re indoors for an extended period of time.

Researchers have also found that heavy breathing and singing can propel aerosolized viral particles farther and increase the risk of transmission.

During one fitness instructor workshop, about 30 participants with no symptoms trained intensely for four hours, according to research published by the CDC. Eight participants later tested positive, and more than 100 new cases of coronavirus were traced back to that fitness workshop.

To help mitigate the risk, many gyms are limiting capacity or requiring masks.

And while health experts have recommended staying 6 feet away from others, it’s smart to keep even more distance than that at the gym.

“With all the heavy breathing, you may even want to double the usual 6 feet to 12 feet, just to be safe,” CNN Chief Medical Correspondent Dr. Sanjay Gupta said.

For symptomatic carriers: If it’s been at least 10 days since your symptoms started and at least 24 hours since you’ve had a fever (without the help of fever-reducing medication) and your other symptoms have improved, you can go ahead and stop isolating, the CDC says.

(But it’s important to note symptoms typically don’t show up until several days after infection — and you can be more contagious during this pre-symptomatic time. Also, symptoms can last for weeks or months — including in young people.)

For asymptomatic carriers: People who tested positive but don’t have any symptoms can stop isolating 10 days after the first positive test – as long as they have not subsequently developed symptoms, the CDC says.

But 10 days is just a general guideline: “Because symptoms cannot be used to gauge where these individuals are in the course of their illness, it is possible that the duration of viral shedding could be longer or shorter than 10 days after their first positive test,” the CDC warned. With viral shedding, a person can infect others with the virus, even if they have no symptoms.

Asymptomatic carriers who have tested positive can also stop isolating if they get two negative test results from tests taken more than 24 hours apart. At that point, it’s very unlikely they are still contagious.

Doctors say wearing eye protection (in addition to face masks) could help some people, but it’s not necessary for everyone.

Teachers who have younger students in the classroom are “likely to be in environments where children might pull down their masks, or not be very compliant with them,” epidemiologist Saskia Popescu said. “There is concern that you could get respiratory droplets in the eyes.”

If you’re a health care worker or taking care of someone at home who has coronavirus, it’s smart to wear eye protection, said Dr. Thomas Steinemann, clinical spokesperson for the American Academy of Ophthalmology.

(Note: Regular glasses or sunglasses aren’t enough, because they leave too many gaps around the eyes.)

But if you’re vaccinated or not in a high-risk situation, wearing goggles isn’t necessary.

While it’s still possible to get Covid-19 through the eyes, that scenario is less likely than getting it through your nose or mouth, Steinemann said.

He said if a significant number of people were getting coronavirus through their eyes, doctors would probably see more Covid-19 patients with conjunctivitis, also known as pink eye (though having pink eye doesn’t necessarily mean you have coronavirus).

The CDC does not recommend using plastic face shields for everyday activities or as a substitute for face masks. There are a few exceptions, such as for those who are hearing-impaired and rely on lip-reading or those who have physical or mental health conditions that would be exacerbated by wearing a cloth face mask.

“Cloth face coverings are a critical preventive measure and are most essential in times when social distancing is difficult,” the CDC says.

Clinical and laboratory studies show cloth face coverings reduce the spray of droplets when worn over the nose and mouth – what the CDC refers to as “source control.” And many people are contagious even when they don’t have any symptoms and don’t know they’re infected.

Face shields worn in addition to masks can provide an added layer of protection and can also help people stop touching their faces. Workers who are around people for long periods of time, such as grocery store workers or hospital personnel, may want to wear face shields in addition to masks, to increase their protection.

If someone must use a face shield without a mask, the CDC says the shield “should wrap around the sides of the wearer’s face and extend to below the chin. Disposable face shields should only be worn for a single use. Reusable face shields should be cleaned and disinfected after each use.”

During the 2019-2020 flu season, an estimated 22,000 people in the US died from the flu, according to the CDC.

With Covid-19, the first known US death was in February 2020. By January 27, more than 427,000 people had died, according to data from Johns Hopkins University. Covid-19 has now taken more than half a million US lives.

There are other reasons why coronavirus can be more dangerous than the flu:

    . Research indicates a person with the flu infects an average of 1.28 other people, CNN Chief Medical Correspondent Dr. Sanjay Gupta said. With coronavirus, “it’s likely between 2 and 3” other people. But mitigation efforts can drastically reduce that number. . People with coronavirus might not get symptoms for 14 days, and some get no symptoms at all. But they can still infect others unknowingly. The incubation period for the flu is shorter, and most people get symptoms within two days of infection.

Children can be more reluctant because they’re more sensitive to new things than adults are, said Christopher Willard, a psychiatry lecturer at Harvard Medical School.

“There’s also the weird psychological aspect of not being able to see their own face or other people’s faces and facial expressions,” which can hinder their feelings of comfort or safety, he said.

To ease their mask fears, try buying or making masks with fun designs on them. Or have your child customize his or her own masks by drawing on them with markers.

You can also order children’s face masks with superheroes on them or show your kids photos of their favorite celebrities wearing masks.

It’s also important to set a good example by wearing a mask yourself. Show your children your own mask, and let them know that by wearing one, they’ll be just like Mom or Dad.

First, make sure the top of your mask fits snugly against your skin (to minimize vapor from your breath from going up toward your eyes). Then put your glasses over the snug-fitting top portion of your mask.

If that doesn’t do the trick, soap and water can create a barrier that prevents glasses from fogging up. Here’s how.

“Having cancer currently increases your risk of severe illness from COVID-19,” the CDC says. “At this time, it is not known whether having a history of cancer increases your risk.”

Researchers found that patients whose cancer was getting worse or spreading were more than five times more likely to die in a month if they caught Covid-19.

But there are steps cancer patients can take to stay as healthy as possible:

  • Make sure you have at least a 30-day supply of your medications.
  • Don’t delay any life-saving treatment or emergency care during this pandemic.
  • Talk with your healthcare provider about your individual level of risk based on your condition, your treatment, and the level of transmission in your community.
  • Don’t stop taking your medicines or alter your treatment plan without talking to your healthcare provider.
  • Call your healthcare provider if you think you may have been exposed to the novel coronavirus.
  • Read the CDC’s tips for preventing infections in cancer patients.

Technically, it can, but HVAC (heating/ventilation/air conditioning) systems are not thought to be a significant factor in the spread of coronavirus.

Many modern air conditioning systems will either filter out or dilute the virus. Ventilation systems with highly effective filters are a key way to eliminate droplets from the air, said Harvard environmental health researcher Joseph Gardner Allen.

Filters are rated by a MERV system – their “minimum efficiency reporting value” that specifies their ability to trap tiny particles. The MERV ratings go from 1 to 20. The higher the number, the better the filtration.

HEPA filters have the highest MERV ratings, between 17 and 20. HEPA filters are used by hospitals to create sterile rooms for surgeries and to control infectious diseases. They’re able to remove 99.97% of dust, pollen, mold, bacteria and other airborne particles as small as 0.3 microns.

For context, this coronavirus is thought to be between 0.06 to 1.4 microns in size.

But “HEPA filtration is not always going to be feasible or practical,” Allen said. “But there are other filters that can do the job. What is recommended now by the standard setting body for HVAC is a MERV 13 filter.”

High-efficiency filters in the 13-to-16 MERV range are often used in hospitals, nursing homes, research labs and other places where filtration is important.

“If you’re an owner of a home, building or mall, you want to have someone to assess your system and install the largest MERV number filter the system can reliably handle without dropping the volume of air that runs through it,” advised Erin Bromage, an associate professor of biology at the University of Massachusetts Dartmouth.

“In addition, virtually all modern air conditioning systems in commercial buildings have a process called makeup air where they bring in air from outside and condition it and bring it inside,” Bromage said. “It’s worse in regards to energy, but the more outside air we bring in, the more dilution of the virus we have and then the safer you are.”

Asymptomatic describes a person who is infected but does not have symptoms. With Covid-19, asymptomatic carriers can still easily infect others without knowing it. So if you’re infected but don’t feel sick, you could still get others very sick.

Some medical professionals differentiate between truly asymptomatic carriers – those who don’t currently have and will never have symptoms – from “pre-symptomatic” carriers – those who don’t have symptoms now, but will get them later. But the general public often uses the term “asymptomatic” to describe both categories of infected people.

An N95 respirator provides the best protection. But throughout the pandemic, N95s have been in high demand and short supply.

As for other masks, different types have different levels of effectiveness, according to researchers at Florida Atlantic University.

They compared four types of face masks commonly used by the public: a stitched mask with two layers of fabric, a commercial cone mask, a folded handkerchief, and a bandana. Researchers tested each to see which would likely offer the most protection if someone coughed or sneezed.

— With a cone-style mask, the droplets traveled about 8 inches.

— A folded handkerchief performed worse, with droplets traveling 1 foot, 3 inches.

— The bandana gave the least amount of protection of the cloth masks tested, with droplets traveling 3 feet.

— Still, any kind of cloth mask is better than none, the researchers found. Without any covering, droplets were able to travel 8 feet.

“People need to know that wearing masks can reduce transmission of the virus by as much as 50%, and those who refuse are putting their lives, their families, their friends, and their communities at risk,” said Dr. Christopher Murray, director of the University of Washington’s Institute for Health Metrics and Evaluation.

Unlike SARS and swine flu, the novel coronavirus is both highly contagious and especially deadly, CNN Chief Medical Correspondent Dr. Sanjay Gupta said.

“SARS was also a coronavirus, and it was a new virus at the time,” Gupta said. “In the end, we know that SARS ended up infecting 8,000 people around the world and causing around 800 deaths. So very high fatality rate, but it didn’t turn out to be very contagious.”

The swine flu, or H1N1, “was very contagious and infected some 60 million people in the United States alone within a year,” Gupta said. “But it was far less lethal than the flu even — like 1/3 as lethal as the flu.”

What makes the novel coronavirus different is that “this is both very contagious … and it appears to be far more lethal than the flu as well.”

“People can be contagious without symptoms. And in fact – a little bit strangely in this case — people tend to be the most contagious before they develop symptoms, if they’re going to develop symptoms,” CNN Chief Medical Correspondent Dr. Sanjay Gupta said.

“They call that the pre-symptomatic period. So people tend to have more virus at that point seemingly in their nose, in their mouth. This is even before they get sick. And they can be shedding that virus into the environment.”

Some people infected with coronavirus never get symptoms. But it’s easy for these asymptomatic carriers to infect others, said Anne Rimoin, an epidemiology professor at UCLA’s School of Public Health.

“When you speak, sometimes you’ll spit a little bit,” she said. “You’ll rub your nose. You’ll touch your mouth. You’ll rub your eyes. And then you’ll touch other surfaces, and then you will be spreading virus if you are infected and shedding asymptomatically.”

That’s why health officials suggests people wear face masks while in public and when it’s difficult to stay 6 feet away from others.

The odds of transmitting coronavirus through sex hasn’t been thoroughly studied, though it has been found to exist in men’s semen.

But we do know Covid-19 is a highly contagious respiratory illness that can spread via saliva, coughs, sneezes, talking or breathing — with or without symptoms of illness.

So three Harvard physicians examined the likelihood of getting or giving Covid-19 during sex and made several recommendations.

For partners who haven’t been isolating together, they should wear masks and avoid kissing, the authors write.

In addition to wearing masks, people who have sex with partners outside of their home should also shower before and after avoid sex acts that involve the oral transmission of bodily fluids clean up the area afterward with soap or alcohol wipes to reduce their likelihood of infection.

Yes, some young adults have suffered strokes after getting coronavirus.

“The virus seems to be causing increased clotting in the large arteries, leading to severe stroke,” said Dr. Thomas Oxley, a neurosurgeon at Mount Sinai Health System in New York.

“Most of these patients have no past medical history and were at home with either mild symptoms (or in two cases, no symptoms) of Covid.”

But since then, the CDC, the US Surgeon General and other doctors have changed their recommendations and are now urging the widespread use of face masks.

“Everyone should wear a cloth face cover when they have to go out in public, for example to the grocery store or to pick up other necessities,” the CDC said.

Scientists have made many recent discoveries about the new coronavirus, including:

  • It’s easy to spread this virus by just talking or breathing.
  • This coronavirus is highly contagious. Without mitigation efforts like stay-at-home orders, each person with coronavirus infects, on average, another two to three other people. That makes it twice as contagious as the flu.
  • This virus has a long incubation period – up to 14 days – giving a wide window of opportunity for people to infect others before they even know they’re infected.
  • Carriers may be most contagious in the 48 hours before they get symptoms, making transmission even more blind.

In other words, it’s not just people who are sneezing and coughing who can spread coronavirus. It’s often people who look completely normal and don’t have a fever. And that could include you.

Doctors say getting vaccinated is the best way to prevent coronavirus infection.

If you’re not vaccinated, it’s best to take the stairs if you can. But if you can’t, emergency room physician Dr. Leana Wen offers several tips:

  • Wear a mask. Not only does wearing a mask reduce your risk of inhaling the virus — which can linger in the air for 8 minutes — it also helps reduce your chances of infecting others if you are an asymptomatic carrier.
  • Use a tissue to push the elevator buttons. If you don’t have a tissue, use your elbow, then wash or disinfect that area when you can.
  • Try to keep your distance from anyone else inside the elevator as much as possible.

For those not fully vaccinated, try to avoid public restrooms if you can, said microbiologist Ali Nouri, president of the Federation of American Scientists. But he acknowledged that’s not always possible: “Sometimes when you gotta go, you gotta go.”

Close contact with others is the most significant risk in a public restroom, Nouri said. So if there’s a single-person bathroom available that doesn’t have multiple stalls, using that might be best.

If you do use a multi-stall public restroom, Nouri offers the following tips:

  • Don’t use your freshly washed hands to turn off the water with the germ-laden faucet handle. Instead, use a paper towel to turn off the water and open the bathroom door. Throw away the paper towel immediately afterward.
  • Wear a face mask. “Masks are one of the most effective ways to stop human-to-human transmission,” Nouri said. “If people in a public bathroom are not wearing masks, think twice before going in.”
  • If the restroom looks crowded, wait until it clears out, if you can. “You’re reducing the risk of inhaling aerosolized particles from other people,” Nouri said.

Yes — as long as you use the right kind of sanitizer and use it correctly.

Hand sanitizers “need to have at least 60% alcohol in them,” said Dr. William Schaffner, professor of preventative medicine and infectious disease at Vanderbilt University School of Medicine.

And don’t just put a little dollop in your hand and smear it around quickly.

“You’ve got to use enough and get it all over the surfaces,” Schaffner said. “Rub it all over your hands, between your fingers and on the back of your hands.”

But it’s always better to thoroughly wash your hands, if you’re able to.

“Alcohol is pretty effective at killing germs, but it doesn’t wash away stuff,” said Dr. John Williams, a virologist at the University of Pittsburgh Medical Center Children’s Hospital of Pittsburgh.

“If somebody’s just sneezed into their hand, and their hand is covered with mucus, they would have to use a lot more alcohol to inactivate that bacteria or virus.”

A study published in The New England Journal of Medicine found that people with Type A blood have a higher risk of getting infected with coronavirus and developing severe symptoms, while people with Type O blood have a lower risk – but the study has caveats.

The researchers cannot say if blood type is a direct cause of the differences in susceptibility. It could be that genetic changes that affect someone’s risk also just happen to be linked with blood type, they said.

The study’s findings, while plausible, may mean very little for the average person, said Dr. Roy Silverstein, a hematologist and chairman of the department of medicine at the Medical College of Wisconsin.

“The absolute difference in risk is very small,” he said. “The risk reduction may be statistically significant, but it is a small change in actual risk. You never would tell somebody who was Type O that they were at smaller risk of infection.”

The bottom line: “All of us are susceptible to this virus,” said Dr. Maria Van Kerkhove, technical lead for the World Health Organization’s Covid-19 response.

“It’s probably safe if you’re not at home,” said Dr. Leana Wen, an emergency room physician. She suggested leaving the windows open to improve ventilation and asking the cleaners to use your own cleaning supplies so they don’t bring items that have been in other people’s houses.

That’s “not a great idea,” said Dr. Joseph Vinetz, a professor of infectious diseases at Yale School of Medicine. “We have no evidence about that.”

“If there’s a metal piece in an N95 or surgical mask and even staples, you can’t microwave them,” he said. “It’ll blow up.”

Vinetz said cloth masks can be washed and reused, and even disposable masks can be reused if you let them sit for several days.

To disinfect masks that you can’t wash, Vinetz recommends leaving them in a clean, safe place in your home for a few days. After that, it should no longer be infectious, as this coronavirus is known to survive on hard surfaces for only up to three days.

You could be hundreds of times more likely to save that dying person’s life than you are to die from Covid-19 if you contract it after performing CPR, according to a report published by a group of Seattle emergency room physicians in the journal Circulation.

But it’s important to act quickly for CPR to be effective.

“The chance of survival goes down by 10% for every minute without CPR,” said Dr. Comilla Sasson, vice president for science and innovation in emergency cardiovascular care at the American Heart Association. “It’s a 10-minute window to death in many cases.”

If you’re not certified in CPR, performing chest compressions could also buy more time until help arrives. Bystanders should “provide high-quality chest compressions by pushing hard and fast in the middle of the victim’s chest, with minimal interruptions,” the American Heart Association said.

If you’re not sure how “fast” to do to those chest compressions, singing any of these popular songs will help you get the right rhythm.

It’s not the water you need to worry about. It’s how close you might get to other people.

“Properly maintained pool water will not be a source of spread of the virus. The chlorine that’s in it will inactivate the virus fairly quickly,” immunologist Erin Bromage said.

“The level of dilution that would happen in a pool or an ocean or a large freshwater body would not lead to enough virus to establish an infection. But when you do this, you need to just make sure that we’re maintaining an appropriate physical distance while swimming or sitting in a hot tub.”

That’s because it’s easy for infected people with no symptoms to spread the virus if they’re within 6 feet from each other. If you have an indoor pool or hot tub, even 6 feet might not be enough distance.

Randomly spraying open places is largely a waste of time, health experts say.

It can actually do more harm than good. “Spraying disinfectants can result in risks to the eyes, respiratory or skin irritation,” the World Health Organization said.

“Spraying or fumigation of outdoor spaces, such as streets or marketplaces, is also not recommended to kill the COVID-19 virus or other pathogens because disinfectant is inactivated by dirt and debris, and it is not feasible to manually clean and remove all organic matter from such spaces,” the WHO said.

“Moreover, spraying porous surfaces, such as sidewalks and unpaved walkways, would be even less effective.” Besides, the ground isn’t typically a source of infection, the WHO said.

And once the disinfectant wears off, an infected person could easily contaminate the surface again.

Any large gathering can increase the spread because this coronavirus is transmissible by talking or even just breathing. Carriers of the virus can be contagious even if they don’t have symptoms.

And when people are “shouting and cheering loudly, that does produce a lot of droplets and aerosolization that can spread the virus to people,” said Dr. James Phillips, a physician and assistant professor at George Washington University Hospital.

So doctors and officials say its important to get vaccinated or wear a face mask and try to keep your distance from others as much as possible.

“To date, there is no evidence that very high vitamin D levels are protective against COVID-19 and consequently medical guidance is that people should not be supplementing their vitamin D levels beyond those which are currently recommended by published medical advice,” wrote Robin May, director of the Institute of Microbiology and Infection at the University of Birmingham in the UK.

Vitamin D is important for healthy muscles, strong bones and a powerful immune system. The recommended daily dose of vitamin D for anyone over age 1 is 15 mcg/600 IU per day in the US. For anyone over 70 years of age in the US, the recommended daily intake goes up to 20 mcg/800 IU per day.

But too much vitamin D can lead to a toxic buildup of calcium in your blood that can cause confusion, disorientation, heart rhythm problems, bone pain, kidney damage and painful kidney stones.

“Viruses can live on surfaces and objects — including on money — although your chance of actually getting COVID-19 from cash is probably very low,” emergency medicine physician Dr. Leana Wen said.

The new coronavirus can live for up to 72 hours on stainless steel and plastic, up to 24 hours after landing on cardboard, and up to four hours after landing on copper, according to a study funded by the US National Institutes of Health.

So how do you protect yourself? To avoid touching cash or coins, use contactless methods of payment whenever possible, Wen said.

If you can’t use a contactless form of payment, credit cards and debit cards are much easier to clean and disinfect than cash. But remember that anyone who touches your credit card can also leave germs on it.

If you must use cash, “wash your hands well with soap and water” afterward, Wen said.

The same applies for anything else you touch that might have coronavirus on it. If you can’t wash your hands immediately, use hand sanitzier or disinfectant.

And since Covid-19 is a respiratory disease, make sure you avoid touching your face.

It appears unlikely, but the CDC advises taking precautions.

Experts believe coronavirus is mainly spread during close contact (about 6 feet) with a person who is currently infected, the CDC said.

“This type of spread is not a concern after death,” the CDC said. But it cautions that “we are still learning how it spreads.”

“There may be less of a chance of the virus spreading from certain types of touching, such as holding the hand or hugging after the body has been prepared for viewing,” the CDC said.

“Other activities, such as kissing, washing, and shrouding should be avoided before, during, and after the body has been prepared, if possible.”

If washing the body or shrouding are important religious or cultural practices, “families are encouraged to work with their community’s cultural and religious leaders and funeral home staff on how to reduce their exposure as much as possible,” the CDC said.

“At a minimum, people conducting these activities should wear disposable gloves. If splashing of fluids is expected, additional personal protective equipment (PPE) may be required (such as disposable gown, faceshield or goggles and N-95 respirator).”

Cremated remains can be considered sterile, as infectious agents do not survive incineration-range temperatures, the CDC said.

While some UV light devices are used for hospital disinfection, UV light only kills germs under very specific conditions — including certain irradiation dosages and exposure times, the World Health Organization said.

Two factors are required for UV light to destroy a virus: intensity and time. If the light is intense enough to break apart a virus in a short time, it’s going to be dangerous to people, said Donald Milton, a professor at the University of Maryland.

UVA and UVB light both damage the skin. UVC light is safer for skin, but it will damage tender tissue such as the eyes.

No. The US Food and Drug Administration says you don’t need to wash fresh produce with soap and water, but you should rinse it with plain water.

But it’s still important to wash your hands with soap and water frequently because we often touch our faces without realizing it. And that’s a way coronavirus can spread.

You don’t have to worry about getting coronavirus by “eating” it, though. Even if coronavirus does get into your food, your stomach acid would kill it, said Dr. Angela Rasmussen, a virologist at Columbia University.

Coronavirus can stick to hair, said Dr. David Aronoff, director of the Division of Infectious Diseases at Vanderbilt University Medical Center.

Touching contaminated hair and then touching your mouth, eyes or nose could increase your risk of infection. “Like on the skin, this coronavirus is a transient hitchhiker that can be removed by washing,” Aronoff said.

But that doesn’t mean you have to wash the hair on your head multiple times a day, said dermatologist Dr. Hadley King.

That’s because “living hair attached to our scalps may be better protected by our natural oils that have some antimicrobial properties and may limit how well microbes can attach to the hair,” she said.

“If you are going out into areas that could possibly be contaminated with viral particles, then it would be reasonable to wash the hair daily during the pandemic. But it’s not the same as hand washing – the virus infects us through our mucosal surfaces. If your hair is not falling into your face or you’re not running your fingers through it, then there is less of a risk.”

If your hair does fall into your face, you may want to pull it back to minimize your risk, King said.

As for facial hair, “washing at least daily if not more frequently is wise, depending on how often they touch their face,” Aronoff said.

There have been some reports of animals infected with coronavirus — including two pets in New York and eight big cats at the Bronx Zoo.

Most of those infections came from contact with humans who had coronavirus, like a zoo employee who was an asymptomatic carrier.

But according to the CDC, there is no evidence animals play a significant role in spreading the virus to humans. Therefore, at this time, routine testing of animals for Covid-19 is not recommended.

As always, it’s best to wash your hands after touching an animal’s fur and before touching your face. And if your pet appears to be sick, call your veterinarian.

This “Contact tracing 101” article explains how contact tracing works, how it quashed previous outbreaks, who can get hired, and why tracing is critical to helping reopen economies.

But the US hasn’t been doing nearly enough contact tracing, experts say. Here’s why.

Hot water is best for killing bacteria and viruses in your laundry. But you don’t want to use that kind of scalding hot water on your skin.

Warm water is perfectly fine for washing your hands — as long as you wash them thoroughly (like this) and for at least 20 seconds. (To time yourself, you can hum the “Happy Birthday” song twice or sing a couple of verses from any of these hit songs from the past several decades.)

Cold water will also work, “but you have to make sure you work really vigorously to get a lather and get everything soapy and bubbly,” said chemist Bill Wuest, an associate professor at Emory University. To do that, you might need to sing “Happy Birthday” three times instead of twice.

“Warm water with soap gets a much better lather – more bubbles,” Wuest said. “It’s an indication that the soap is … trying to encapsulate the dirt and the bacteria and the viruses in them.”

Yes, you can use soap and water on surfaces just like you would on your hands to kill coronavirus. But don’t use water alone — that won’t really help.

The outer layer of the virus is made up of lipids, aka fat. Your goal is to break through that fatty barrier, forcing the virus’ guts to spill out and rendering it dead.

In other words, imagine coronavirus is a butter dish that you’re trying to clean.

“You try to wash your butter dish with water alone, but that butter is not coming off the dish,” said Dr. John Williams, chief of pediatric infectious diseases at UPMC Children’s Hospital of Pittsburgh.

“You need some soap to dissolve grease. So soap or alcohol are very, very effective against dissolving that greasy liquid coating of the virus.”

By cutting through the greasy barrier, Williams said, “it physically inactivates the virus so it can’t bind to and enter human cells anymore.”

Yes, coronavirus can live on the soles of shoes, but the risk of getting Covid-19 from shoes appears to be low.

A report published by the CDC highlighted a study from a hospital in Wuhan, China, where this coronavirus outbreak began.

The soles of medical workers’ shoes were swabbed and analyzed, and the study found that the virus was “widely distributed” on floors, computer mice, trash cans and door knobs. But it’s important to note the study was done in a hospital, where the virus was concentrated.

It’s still possible to pick up coronavirus on the bottoms of your shoes by running errands, but it’s unlikely you’ll get sick from it because people don’t often touch the soles of their shoes and then their faces. Because Covid-19 is a respiratory disease, the CDC advises wearing a mask while in public and washing your hands frequently– the correct way.

If you have small children who crawl or regularly touch the floor, it’s a good idea to take your shoes off as soon you get home to prevent coronavirus or bacteria from spreading on the floors.

There’s no evidence that coronavirus can be transmitted through food, the CDC says.

Even if coronavirus does get into your food, your stomach acid would kill it, said Dr. Angela Rasmussen, a virologist at Columbia University.

“When you eat any kind of food, whether it be hot or cold, that food is going to go straight down into your stomach, where there’s a high acidity, low-pH environment that will inactivate the virus,” she said.

But it’s a good idea to disinfect the takeout containers, CNN Chief Medical Correspondent Dr. Sanjay Gupta said. Coronavirus is a respiratory virus, and it’s easy to touch your face without realizing it.

If you don’t have disinfecting wipes, use your own plates or bowls to serve the food. Just make sure to wash your hands after transferring food from the containers.

“There is no evidence that COVID-19 can be spread to humans through the use of pools and hot tubs,” the CDC says.

“Proper operation, maintenance, and disinfection (e.g., with chlorine and bromine) of pools and hot tubs should remove or inactivate the virus that causes COVID-19.”

But health officials still advise staying at least 6 feet away from others because COVID-19 is a respiratory disease. In other words, you probably won’t get coronavirus from the water, but you could get coronavirus from someone close to you in the water.

As for drinking water, doctors say you don’t need to worry about coronavirus in the tap water because most municipal drinking water systems should remove or inactivate the virus.

“To date there has been no information nor evidence to suggest that the new coronavirus could be transmitted by mosquitoes,” the World Health Organization says. There’s also no evidence so far suggesting flies can spread coronavirus.

Yes you can, said Dr. Joseph Vinetz, an infectious diseases professor at Yale School of Medicine.

To disinfect masks that you can’t wash, Vinetz recommends leaving them in a clean, safe place in your home for a few days. After that, it should no longer be infectious, as this coronavirus is known to survive on hard surfaces for only up to three days.

You can reuse cloth masks, too. Just launder them between each use on a high-heat setting.

“That’s a bad idea,” said Dr. Colleen Kraft, an infectious diseases professor at Emory University School of Medicine. “It could definitely kill you.”

But the Reckitt Benckiser Group, which produces Lysol cleaning products, said “under no circumstance” should disinfectants be put into the human body.

Singapore was initially praised for its clampdown on the virus. Even people who had no symptoms but tested positive had to be hospitalized until they tested negative.

But Singapore was also relaxed, allowing businesses, churches, restaurants and schools to stay open during its first wave of the virus. And some communities were overlooked by government testing.

By contrast, Germany, South Korea, Iceland and Taiwan have had among the lowest death rates from Covid-19 in the world.

Taiwan was proactive, launching its Central Epidemic Command Center before the island even confirmed its first infection.

Iceland required all its citizens returning to the country to undergo 14 days of quarantine – regardless of which country they traveled from.

Germany and South Korea quickly launched widespread testing and have some of the highest per-capita testing rates in the world. Their ability to identify and isolate those infected has helped prevent deadlier outcomes.

“I don’t think you need to,” CNN Chief Medical Correspondent Dr. Sanjay Gupta said.

Coronavirus can stay alive for up to three days on stainless steel and plastic. But clothing “is probably more like cardboard — it’s more absorbent, so the virus is unlikely to stay and last that long,” Gupta said.

While coronavirus can stay alive on cardboard for up to 24 hours, viruses generally don’t stick well on surfaces that are in motion.

“If you look at how viruses move through air, they kind of want to move around objects,” Gupta said. “They don’t want to necessarily land on objects. So if you’re moving as human body through the air … (it’s) unlikely to stick to your clothes.”

Not necessarily. Antibodies are a body’s response to bacteria or viruses. But this novel coronavirus is so new, it’s still not clear whether having antibodies to it means you have long-term protection from getting reinfected.

“The thing we don’t know yet is what is the relationship between the level of antibody and the degree of your protection,” Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, told Snapchat’s “Good Luck America” show.

“So you may be positive for an antibody, but not enough to protect you.”

There’s also a risk that some antibody tests might confuse the novel coronavirus with other coronaviruses, like the ones that cause the common cold.

Please don’t. The CDC advises using hand sanitizer that contains at least 60% alcohol.

If the stores are out of hand sanitizer and you want to make your own, the Nebraska Medical Center offers this recipe:

What you’ll need:

  • 2/3 cup 91% isopropyl alcohol (rubbing alcohol)
  • 1/3 cup aloe vera gel
  • Mixing bowl
  • Spoon or something for whisking
  • Small container, such as a 3-oz. travel bottle
  • Optional: essential oil to give your hand sanitizer a fragrance

Directions:
In a mixing bowl, stir isopropyl alcohol and aloe vera gel together until well blended.
Add 8-10 drops of scented essential oil (optional, but nice). Stir.
Pour the homemade hand sanitizer into an empty container and seal. Write “hand sanitizer” on a piece of masking tape and attach to the bottle.

This is not a good time to be vaping or smoking anything, including weed.

“Vaping affects your lungs at every level. It affects the immune function in your nasal cavity by affecting cilia, which push foreign things out,” said Prof. Stanton Glantz, director of the Center for Tobacco Research Control and Education at University of California San Francisco.

When you vape, “the ability of your upper airways to clear viruses is compromised,” Glantz said.

Tobacco smokers are at especially high risk. In a study from China, where the first Covid-19 outbreak occurred, smokers were 14 times more likely to develop severe complications than non-smokers.

Even occasionally smoking marijuana can put you at greater risk.

“What happens to your airways when you smoke cannabis is that it causes some degree of inflammation, very similar to bronchitis, very similar to the type of inflammation that cigarette smoking can cause,” said pulmonologist Dr. Albert Rizzo, chief medical officer for the American Lung Association.

“Now you have some airway inflammation, and you get an infection on top of it. So yes, your chance of getting more complications is there.”

Coronavirus isn’t just infecting young people. It’s killing young, healthy people as well.

Dimitri Mitchell, 18, admits he had a “false sense of security.” But he was later hospitalized with coronavirus and now wants everyone to take it seriously.

“I just want to make sure everybody knows that no matter what their age is, it can seriously affect them. And it can seriously mess them up, like it messed me up,” the Iowa teen said.

“Four days in, the really bad symptoms started coming along. I started having really bad outbreaks, like sweating, and my eyes were really watery. I was getting warmer and warmer, and I was super fatigued. … I would start experiencing the worst headaches I’ve ever felt in my life. They were absolutely horrible.”

Eventually, the teen had to be hospitalized. His mother said she worried he might “fall asleep and never wake up.”

Mitchell is now recovering, but has suffered from long-term effects.

“I just hope everybody’s responsible, because it’s nothing to joke about,” he said. “It’s a real problem, and I want everybody to make sure they’re following social distancing guidelines and the group limits. And just listen to all the rules and precautions and stay up to date with the news and make sure they’re informed.”

No. That’s just a hoax going around the internet.

“The theory that 5G might compromise the immune system and thus enable people to get sick from corona is based on nothing,” said Eric van Rongen, chairman of the International Commission on Non-Ionizing Radiation Protection (ICNIRP).

Ideally, you should limit your children’s potential exposures to coronavirus and work out the safest plan possible with your ex.

The problem: Some state and county family courts might be closed, or open only for emergencies involving abuse or endangerment. So it might be difficult to formally modify pre-existing custody agreements.

But some states may be offering some flexibility during the pandemic. And there may be creative solutions, such as spending more time with one parent now in exchange for extra time with the other parent after the pandemic ends.

Up to three days, depending on the surface. According to a study funded by the US National Institutes of Health:

  • The novel coronavirus is viable up to 72 hours after being placed on stainless steel and plastic.
  • It was viable up to four hours after being placed on copper, and up to 24 hours after being put on cardboard.
  • In aerosols, it was viable for three hours.

Some cases of coronavirus do lead to pneumonia. But the pneumonia vaccine won’t help.

“Vaccines against pneumonia, such as pneumococcal vaccine and Haemophilus influenza type B (Hib) vaccine, only help protect people from these specific bacterial infections,” according to Harvard Medical School.

“They do not protect against any coronavirus pneumonia.”

For unvaccinated people, the CDC “recommends wearing cloth face coverings in public settings where other social distancing measures are difficult to maintain (e.g., grocery stores and pharmacies).”

There are several key points:

  • You can easily make your own mask without knowing how to sew. US Surgeon General Jerome Adams shows how to make face masks with just a T-shirt and rubber bands in this CDC video. You can also use a bandana and a coffee filter.
  • You can still get coronavirus even if you wear a mask. The virus can stay alive on surfaces for up to 3 days, and it’s easy to touch your face whenever you’re not wearing a mask. Also, people often adjust face masks frequently, leading to more touching of the face — a common way that coronavirus spreads.
  • It’s important to wash your cloth mask after every use. Here’s how.
  • Wearing cloth masks is just “an additional, voluntary public health measure,” the CDC said. To protect yourself from getting coronavirus, it’s critical to stay at least 6 feet away from others, wash your hands frequently for at least 20 seconds each time, and stop touching your face.

An antiviral drug must be able to target the specific part of a virus’ life cycle that is necessary for it to reproduce, according to Harvard Medical School.

“In addition, an antiviral drug must be able to kill a virus without killing the human cell it occupies. And viruses are highly adaptive.”

Many health care workers haven’t had enough protective gear to handle the growing influx of coronavirus patients.

Some have resorted to using plastic report covers as masks. The CDC said medical providers might have to use expired masks or reuse them between multiple patients.

But it’s not just subpar protective gear that puts medical workers at risk. It’s also the amount of virus they’re exposed to.

“The viral load — the amount of virus – does determine the severity of your illness,” emergency medicine physician Dr. Leana Wen said. “So that could happen in the case of health care workers who are exposed to a lot more Covid-19 as a result of their work — that they get more severely ill.”

In one study, about 4 in 5 people with confirmed coronavirus in China were likely infected by people who didn’t know they had it, according to research published in the journal “Science.”

“These findings explain the rapid geographic spread of (coronavirus) and indicate containment of this virus will be particularly challenging,” researchers wrote.

In the US, “I think it could be as many as 1 in 3 walking around asymptomatic,” said New Jersey primary care physician Dr. Alex Salerno.

“We have tested some patients that have known exposure to COVID (coronavirus disease). They did not have temperature. Their pulse/(oxygen) was OK.”

Salerno said more testing of people without symptoms is essential.

When asymptomatic carriers test positive, “we isolate them, and we separate them from the people who are not positive,” Salerno said. If more asymptomatic people got tested, “we could get people back to work safely.”

Most coronavirus patients don’t need to be hospitalized. “The vast majority of people – about 80% – will do well without any specific intervention,” said Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases.

Those patients should get plenty of rest, hydrate frequently and take fever-reducing medication.

“The current guidance – and this may change – is that if you have symptoms that are similar to the cold and the flu and these are mild symptoms to moderate symptoms, stay at home and try to manage them,” said Dr. Patrice Harris, president of the American Medical Association.

But about 20% of coronavirus patients get advanced disease. “Older patients and individuals who have underlying medical conditions or are immunocompromised should contact their physician early in the course of even mild illness,” the CDC says.

  • Trouble breathing
  • Persistent pain or pressure in the chest
  • Sudden confusion
  • Bluish lips or face

“This list is not all inclusive,” the CDC says. “Please consult your medical provider for any other symptoms that are severe or concerning.”

No, the water supply is not at risk.

“The COVID-19 virus has not been detected in drinking water,” the CDC says. “Conventional water treatment methods that use filtration and disinfection, such as those in most municipal drinking water systems, should remove or inactivate the virus that causes COVID-19.”

So there’s no need to hoard drinking water, said Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases. Fauci said he and his wife are still drinking tap water.

It may be difficult to know whether your loved one has coronavirus or another illness. So it’s critical to play it safe and not infect yourself and, in turn, others. The CDC suggests:

  • Giving the sick person their own room to stay in, if possible. Keep the door closed.
  • Having only one person serve as the caretaker.
  • Asking the sick person to wear a face mask, if they are able to. If the mask causes breathing difficulties, then the caretaker should wear a mask instead.

Fatigue, fever, dry cough, difficulty breathing and the loss of taste or smell are some of the symptoms of Covid-19.

Symptoms can appear anywhere from 2 days to 2 weeks after exposure, the CDC says. But some people get no symptoms at all and can infect others without knowing it.

The illness varies in its severity. And while many people can recover at home just fine, some people — including young, previously healthy adults — are suffering long-term symptoms.

Don’t visit family members with suspected illness – connect with them virtually. If that person lives with you, limit contact with them and avoid using the same bathroom or bedroom if possible, the CDC advises.

If the person been diagnosed, he or she might be able to recover at home in isolation. Separate yourself as much as possible from your infected family member and keep animals away, too. Continue to use separate restrooms and regularly disinfect them.

Stock up on groceries and household supplies for them while they can’t travel outside and minimize trips to stores. Wash your hands frequently and avoid sharing personal items with the infected person.

If you think you’re developing symptoms, stay home and call your physician.

Yes, you can make both at home.

“Unexpired household bleach will be effective against coronaviruses when properly diluted” if you’re trying to kill coronavirus on a non-porous surface, the US Centers for Disease Control and Prevention said.

The CDC’s recipe calls for diluting 5 tablespoons (or ⅓ cup) of bleach per gallon of water, or 4 teaspoons of bleach per quart of water.

You can also make your own hand sanitizer. The Nebraska Medical Center – famous for its biocontainment unit and treatment of Ebola patients – offers this recipe:

What you’ll need:

  • 2/3 cup 91% isopropyl alcohol (rubbing alcohol)
  • 1/3 cup aloe vera gel
  • Mixing bowl
  • Spoon or something for whisking
  • Small container, such as a 3 oz. travel bottle
  • Optional: essential oil to give your hand sanitizer a fragrance

Directions:
In a mixing bowl, stir isopropyl alcohol and aloe vera gel together until well blended.
Add 8-10 drops of scented essential oil (optional, but nice). Stir.
Pour the homemade hand sanitizer into an empty container and seal.
Write “hand sanitizer” on a piece of masking tape and attach to the bottle.

An employee can be fired if they don’t show up to work and don’t have sick leave that would cover the absence, says Krista Slosburg, an employment attorney at Stokes Lawrence in Seattle.

But there are exceptions. Employers who make workers with Covid-19 come in may be violating Occupational Safety and Health Administration [OSHA] regulations, said Donna Ballman, who heads an employee advocacy law firm in Florida.

If you work in a city or state that requires sick leave and you use it, you can‘t be terminated or disciplined.

But there is no federal mandate that requires companies to offer paid sick leave, and almost a quarter of all US workers don’t get it, according to 2019 government data. Some state and local governments have passed laws that require companies to offer paid sick leave.

The Family and Medical Leave Act (FMLA) can sometimes protect a worker’s job in the event they get sick, but it won’t guarantee they get paid while they’re out.

Employee advocates urge businesses to consider the special circumstances of the Covid-19, and some already have

The Society for Human Resource Management recommends companies “actively encourage sick employees to stay home, send symptomatic employees home until they are able to return to work safely, and require employees returning from high-risk areas to telework during the incubation period (of 14 days).”

If a manager feels an employee’s illness poses a direct threat to colleagues’ safety, the manager may be able to insist the employee be evaluated by a doctor, said Alka Ramchandani-Raj, an attorney specializing in workplace safety.

Since Covid-19 is a respiratory disease, some airlines are now requiring passengers to wear face masks during the flight, except for while eating or drinking.

Health experts suggest eating, drinking and using the restroom before getting on the plane, to eliminate the need to take off your mask or go into a cramped lavatory on board.

And always be mindful of where your hands have been, travel medicine specialist Dr. Richard Dawood said.

Airport handrails, door handles and airplane lavatory levers are notoriously dirty.

“It is OK to touch these things as long as you then wash or sanitize your hands before contaminating your face, touching or handling food,” Dawood said.

“Hand sanitizers are great. So are antiseptic hand wipes, which you can also use to wipe down armrests, remote controls at your seat and your tray table.”

People who are immunocompromised “are at higher risk from this illness, as well as other illnesses like the flu. Avoiding contact with ill people is crucial,” Washington state’s latter are at greater risk for severe disease,” according to researchers from the Washington University School of Medicine.

Stay home. Call your doctor to talk about your symptoms and let them know you’re coming for an appointment so they can prepare for your visit, the CDC says.

Only a Covid-19 test can diagnose you with coronavirus, but if you suspect you have it, isolate yourself at home.

Many patients with coronavirus are able to recover at home. If you’ve been diagnosed and your illness is worsening, seek medical attention promptly. You may need to be monitored in a hospital.

No. Those products work on surfaces but can be dangerous to your body.

There are some chemical disinfectants, including bleach, 75% ethanol, peracetic acid and chloroform, that may kill the virus on surfaces.

But if the virus is already in your body, putting those substances on your skin or under your nose won’t kill it, the World Health Organization says. And those chemicals can harm you.

There’s no evidence from the outbreak that eating garlic, sipping water every 15 minutes or taking vitamin C will protect people from the new coronavirus. Same goes for using essential oils or colloidal silver.

Some people with coronavirus have mild or no symptoms. And in some cases, symptoms don’t appear until up to 14 days after infection.

During that incubation period, it’s possible to get coronavirus from someone with no symptoms. It’s also possible you may have coronavirus without feeling sick and are accidentally infecting others.

Experts said cuts in federal funding for public health and problems with early testing forced the US to play catch-up.

Problems with public health infrastructure: Two years ago, the CDC stopped funding epidemic prevention activities in 39 countries, including China. This happened because the Trump administration refused to allocate money to a program that started during the 2014 Ebola outbreak.

Former CDC director Dr. Tom Frieden warned that move “would significantly increase the chance an epidemic will spread without our knowledge and endanger lives in our country and around the world.”

Problems with the testing: Malfunctions, shortages and delays in availability have all contributed to the slowdown.

In the first few weeks of the outbreak in the US, the CDC was the only facility in the country that could confirm test results — even though a World Health Organization test became available around the same time.

Some test kits that were sent around the country were flawed — a move that put the US behind about “four to five weeks,” says Dr. Rob Davidson, executive director of the Committee to Protect Medicare.

No antibiotics are effective against Covid-19 because the disease is caused by a viral infection, not a bacterial infection.

“However, if you are hospitalized for the [coronavirus], you may receive antibiotics because bacterial co-infection is possible,” the World Health Organization says.

There is no known cure for the novel coronavirus.

No. There are some interesting coincidences in the 1981 fiction novel, which says “a severe pneumonia-like illness will spread around the globe” around the year 2020. Modern editions of the book call the biological strain “Wuhan-400,” and the current coronavirus outbreak started in Wuhan, China.

But there are important differences between the book and reality. The original version of the book called the strain the “Gorki-400,” in reference to a Russian locality, before it was later changed to the “Wuhan-400.” In the book, the virus was man-made, while scientists believe the novel coronavirus started in animals and jumped to humans. And in the book, the virus had a 100% mortality rate. Early estimates of the mortality rate for this coronavirus outbreak range from 2-4%.

Hand dryers can’t kill the virus, according to WHO. The organization also says that UV lamps shouldn’t be used to sterilize hands or other areas of the body because the radiation can irritate skin.

Drinking hot water or taking hot baths won’t kill it, either.

No. “The new coronavirus cannot be transmitted through goods manufactured in China or any country reporting Covid-19 cases,” the World Health Organization says.

“Even though the new coronavirus can stay on surfaces for a few hours or up to several days (depending on the type of surface), it is very unlikely that the virus will persist on a surface after being moved, travelled, and exposed to different conditions and temperatures,” WHO said.


BARBICIDE® Infection Control Best Practices

Keeping yourself and your clients safe should be a top priority every day in the salon. That said, when there are new pathogenic threats, it should remind us of the importance of adherence to proper infection control guidelines.

Porous vs. Non-porous

Things in our world can be categorized as either porous or non-porous. Porous items are things that can absorb liquids. Liquids can run through them, or they may be made of mostly liquid. Examples of porous items in the salon include your towels, neck strips and you! Non-porous items are generally made of glass, metal or plastic. Liquids cannot be absorbed or passed through these materials. In every state, porous items must be discarded after every service because there is no way to make them safe for use on multiple clients. Non-porous items may be used on multiple clients, but in every state, they must be cleaned and disinfected prior to use. That is where disinfectants come in!

Disinfectants are chemicals that are designed to destroy the “germs” we are concerned about in the salon – bacteria, viruses and fungi. Disinfectants must be EPA registered (proof that they work as stated) and be bactericidal, virucidal and fungicidal. The steps to proper disinfection are as follows:

  1. Wash non-porous item using either soap/water or a chemical cleaner (Ship-Shape®)
  2. Rinse and dry item
  3. Immerse, wipe or spray your item with an appropriate disinfectant (BARBICIDE®)
  4. Adhere to contact time listed on the label. It might say something like “ensure the item is fully immersed for 10 minutes” or “surface must stay visibly wet for 2 full minutes”. The time referenced is for how long it takes to destroy every pathogen listed on the label.
    • BARBICIDE® Concentrate immersion contact time: 10 minutes
    • BARBICIDE® Spray contact time: 10 minutes
    • BARBICIDE® Wipes contact time: 2 minutes
    1. It is important that disinfectants used for immersion be changed DAILY. This is a requirement of the EPA.

    In addition, there are other things you can do to protect yourself, your clients and everyone around you.


    Related Items

    Best Foaming Cleaner: ToyLife's Foaming Toy Cleaner

    More than 3,700 people trust this foaming cleanser with their favorite toys thanks to an alcohol-, paraben-, and sulfate-free formula. It's gentle on toys but tough on germs, effectively killing bacteria on both porous and non-porous surfaces. Although it does contain fragrance-a sweet floral scent-shoppers say it doesn't linger once the toy is rinsed off. Plus, it only takes 10 seconds to sanitize your entire toy.

    Best Spray: Lelo Antibacterial Toy Cleaning Spray

    Lelo's sex toys are top-of-the-line, so it's no surprise that the company's Antibacterial Toy Cleaning Spray is just as great. (It's also Ella Paradis's best-selling cleanser, according to Del Monte.) Unlike most other options, this body-safe spray doesn't need to be rinsed off. You simply spray the ph-balanced formula directly onto your toy, leave it for five seconds, and wipe with a towel. But don't mistake the ease of use with lack of efficiency: It still kills 99.9% of germs. Due to the addition of zinc salt, which is meant to reduce skin irritation, it's only safe for rubber, latex, and silicone.

    Best Fragrance-Free: Pjur Med Clean Spray

    Del Monte tells Health that this unscented spray is also one of Ella Paradis' most popular cleansers. Although technically for bodily use, it's safe for rubber and silicone toys-and the easiest way to prevent infection. The dermatologist-tested and tasteless spray kills bacteria, fungus, and even viruses like Hepatitis B and HIV to help reduce the chance of STDs spreading after using toys with a partner, according to the brand.

    Best Scented: Shibari Revive Toy Cleaner

    Although Del Monte strongly suggests skipping fragrance, it's still common in many cleansers and popular among shoppers. This water-based formula has a light, fresh scent that leaves toys smelling undeniably clean (regardless of the areas they've explored the night before). Adored by more than 1,500 people, it's compatible with silicone, latex, and rubber materials. More importantly, it's made without alcohol, parabens, glycerin, or triclosan (a potentially harmful chemical included in some antibacterial soaps).

    Best Multi-Use: Maude No. 0

    This unscented spray does double duty as a sanitizer for both your hands and your favorite vibrator. The hydrating formula contains just three ingredients: ethyl alcohol, glycerin, and coconut oil to safely remove up to 99.9% of germs. It quickly absorbs into the skin or can be rinsed off of silicone surfaces with water. Each recyclable glass bottle contains enough sanitizer for up to 185 uses.

    Best UV Cleaner: Uvee Home Play UV Cleaner

    Spend more time playing and less time cleaning by opting for a UV cleaning system. It uses germicidal UV-C rays to kill 99.9% of bacteria. According to UVee, the UV wavelength enters microorganisms and destroys their DNA, preventing them from duplicating. (You should still rinse your toys to remove any visible fluids.) Discreet enough to leave on the nightstand, it also charges your toys and has a lock to keep it private from prying eyes.

    Best for Travel: Lovehoney Fresh Toy Cleaner

    Hundreds of shoppers gave this cleanser a perfect rating for its ability to leave toys squeaky clean. Although it's water-based, people say the formula effectively removes any residue and leaves toys completely odorless (including butt plugs). Plus, its spray nozzle applicator lets you direct the cleaner to hard-to-reach places, like deep crevices, and avoid areas you don't want to clean, like charging ports. Bonus: It's safe for all types of sex toys.

    Best Wipes: Afterglow Toy Tissues

    Del Monte swears by these versatile cleansing wipes to keep her toys in pristine condition. The antibacterial formula not only disinfects toys, but it's also pH-balanced to safely refresh intimate areas post-sex. She calls the added bergamot essence a "cherry on top" because it makes the skin feel and smell refreshed without fragrance.

    Sign up for our Health Shopping newsletter to get your daily dose of retail therapy with great deals handpicked by our editors - straight to your inbox.


    Sterilizing Practices

    The delivery of sterile products for use in patient care depends not only on the effectiveness of the sterilization process but also on the unit design, decontamination, disassembling and packaging of the device, loading the sterilizer, monitoring, sterilant quality and quantity, and the appropriateness of the cycle for the load contents, and other aspects of device reprocessing. Healthcare personnel should perform most cleaning, disinfecting, and sterilizing of patient-care supplies in a central processing department in order to more easily control quality. The aim of central processing is the orderly processing of medical and surgical instruments to protect patients from infections while minimizing risks to staff and preserving the value of the items being reprocessed 957 . Healthcare facilities should promote the same level of efficiency and safety in the preparation of supplies in other areas (e.g., operating room, respiratory therapy) as is practiced in central processing.

    Ensuring consistency of sterilization practices requires a comprehensive program that ensures operator competence and proper methods of cleaning and wrapping instruments, loading the sterilizer, operating the sterilizer, and monitoring of the entire process. Furthermore, care must be consistent from an infection prevention standpoint in all patient-care settings, such as hospital and outpatient facilities.

    A sterilization process should be verified before it is put into use in healthcare settings. All steam, ETO, and other low-temperature sterilizers are tested with biological and chemical indicators upon installation, when the sterilizer is relocated, redesigned, after major repair and after a sterilization failure has occurred to ensure they are functioning prior to placing them into routine use. Three consecutive empty steam cycles are run with a biological and chemical indicator in an appropriate test package or tray. Each type of steam cycle used for sterilization (e.g., vacuum-assisted, gravity) is tested separately. In a prevacuum steam sterilizer three consecutive empty cycles are also run with a Bowie-Dick test. The sterilizer is not put back into use until all biological indicators are negative and chemical indicators show a correct end-point response 811-814, 819, 958 .

    Biological and chemical indicator testing is also done for ongoing quality assurance testing of representative samples of actual products being sterilized and product testing when major changes are made in packaging, wraps, or load configuration. Biological and chemical indicators are placed in products, which are processed in a full load. When three consecutive cycles show negative biological indicators and chemical indicators with a correct end point response, you can put the change made into routine use 811-814, 958 . Items processed during the three evaluation cycles should be quarantined until the test results are negative.

    The central processing area(s) ideally should be divided into at least three areas: decontamination, packaging, and sterilization and storage. Physical barriers should separate the decontamination area from the other sections to contain contamination on used items. In the decontamination area reusable contaminatedsupplies (and possibly disposable items that are reused) are received, sorted, and decontaminated. The recommended airflow pattern should contain contaminates within the decontamination area and minimize the flow of contaminates to the clean areas. The American Institute of Architects 959 recommends negative pressure and no fewer than six air exchanges per hour in the decontamination area (AAMI recommends 10 air changes per hour) and 10 air changes per hour with positive pressure in the sterilizer equipment room. The packaging area is for inspecting, assembling, and packaging clean, but not sterile, material. The sterile storage area should be a limited access area with a controlled temperature (may be as high as 75°F) and relative humidity (30-60% in all works areas except sterile storage, where the relative humidity should not exceed 70%). 819 The floors and walls should be constructed of materials capable of withstanding chemical agents used for cleaning or disinfecting. Ceilings and wall surfaces should be constructed of non-shedding materials. Physical arrangements of processing areas are presented schematically in four references 811, 819, 920, 957 .

    As repeatedly mentioned, items must be cleaned using water with detergents or enzymatic cleaners 465, 466, 468 before processing. Cleaning reduces the bioburden and removes foreign material (i.e., organic residue and inorganic salts) that interferes with the sterilization process by acting as a barrier to the sterilization agent 179, 426, 457, 911, 912 . Surgical instruments are generally presoaked or prerinsed to prevent drying of blood and tissue. Precleaning in patient-care areas may be needed on items that are heavily soiled with feces, sputum, blood, or other material. Items sent to central processing without removing gross soil may be difficult to clean because of dried secretions and excretions. Cleaning and decontamination should be done as soon as possible after items have been used.

    Several types of mechanical cleaning machines (e.g., utensil washer-sanitizer, ultrasonic cleaner, washer-sterilizer, dishwasher, washer-disinfector) may facilitate cleaning and decontamination of most items. This equipment often is automated and may increase productivity, improve cleaning effectiveness, and decrease worker exposure to blood and body fluids. Delicate and intricate objects and heat- or moisture-sensitive articles may require careful cleaning by hand. All used items sent to the central processing area should be considered contaminated (unless decontaminated in the area of origin), handled with gloves (forceps or tongs are sometimes needed to avoid exposure to sharps), and decontaminated by one of the aforementioned methods to render them safer to handle. Items composed of more than one removable part should be disassembled. Care should be taken to ensure that all parts are kept together, so that reassembly can be accomplished efficiently 811 .

    Investigators have described the degree of cleanliness by visual and microscopic examination. One study found 91% of the instruments to be clean visually but, when examined microscopically, 84% of the instruments had residual debris. Sites that contained residual debris included junctions between insulating sheaths and activating mechanisms of laparoscopic instruments and articulations and grooves of forceps. More research is needed to understand the clinical significance of these findings 960 and how to ensure proper cleaning.

    Personnel working in the decontamination area should wear household-cleaning-type rubber or plastic gloves when handling or cleaning contaminated instruments and devices. Face masks, eye protection such as goggles or full-length faceshields, and appropriate gowns should be worn when exposure to blood and contaminated fluids may occur (e.g., when manually cleaning contaminated devices) 961 . Contaminated instruments are a source of microorganisms that could inoculate personnel through nonintact skin on the hands or through contact with the mucous membranes of eyes, nose, or mouth 214, 811, 813 . Reusable sharps that have been in contact with blood present a special hazard. Employees must not reach with their gloved hands into trays or containers that hold these sharps to retrieve them 214 . Rather, employees should use engineering controls (e.g., forceps) to retrieve these devices.

    Once items are cleaned, dried, and inspected, those requiring sterilization must be wrapped or placed in rigid containers and should be arranged in instrument trays/baskets according to the guidelines provided by the AAMI and other professional organizations 454, 811-814, 819, 836, 962 . These guidelines state that hinged instruments should be opened items with removable parts should be disassembled unless the device manufacturer or researchers provide specific instructions or test data to the contrary 181 complex instruments should be prepared and sterilized according to device manufacturer&rsquos instructions and test data devices with concave surfaces should be positioned to facilitate drainage of water heavy items should be positioned not to damage delicate items and the weight of the instrument set should be based on the design and density of the instruments and the distribution of metal mass 811, 962 . While there is no longer a specified sterilization weight limit for surgical sets, heavy metal mass is a cause of wet packs (i.e., moisture inside the case and tray after completion of the sterilization cycle) 963 . Other parameters that may influence drying are the density of the wraps and the design of the set 964 .

    There are several choices in methods to maintain sterility of surgical instruments, including rigid containers, peel-open pouches (e.g., self-sealed or heat-sealed plastic and paper pouches), roll stock or reels (i.e., paper-plastic combinations of tubing designed to allow the user to cut and seal the ends to form a pouch) 454 and sterilization wraps (woven and nonwoven). Healthcare facilities may use all of these packaging options. The packaging material must allow penetration of the sterilant, provide protection against contact contamination during handling, provide an effective barrier to microbial penetration, and maintain the sterility of the processed item after sterilization 965 . An ideal sterilization wrap would successfully address barrier effectiveness, penetrability (i.e., allows sterilant to penetrate), aeration (e.g., allows ETO to dissipate), ease of use, drapeability, flexibility, puncture resistance, tear strength, toxicity, odor, waste disposal, linting, cost, and transparency 966 . Unacceptable packaging for use with ETO (e.g., foil, polyvinylchloride, and polyvinylidene chlorine [kitchen-type transparent wrap]) 814 or hydrogen peroxide gas plasma (e.g., linens and paper) should not be used to wrap medical items.

    In central processing, double wrapping can be done sequentially or nonsequentially (i.e., simultaneous wrapping). Wrapping should be done in such a manner to avoid tenting and gapping. The sequential wrap uses two sheets of the standard sterilization wrap, one wrapped after the other. This procedure creates a package within a package. The nonsequential process uses two sheets wrapped at the same time so that the wrapping needs to be performed only once. This latter method provides multiple layers of protection of surgical instruments from contamination and saves time since wrapping is done only once. Multiple layers are still common practice due to the rigors of handling within the facility even though the barrier efficacy of a single sheet of wrap has improved over the years 966 . Written and illustrated procedures for preparation of items to be packaged should be readily available and used by personnel when packaging procedures are performed 454 .

    All items to be sterilized should be arranged so all surfaces will be directly exposed to the sterilizing agent. Thus, loading procedures must allow for free circulation of steam (or another sterilant) around each item. Historically, it was recommended that muslin fabric packs should not exceed the maximal dimensions, weight, and density of 12 inches wide × 12 inches high × 20 inches long, 12 lbs, and 7.2 lbs per cubic foot, respectively. Due to the variety of textiles and metal/plastic containers on the market, the textile and metal/plastic container manufacturer and the sterilizer manufacturers should be consulted for instructions on pack preparation and density parameters 819 .

    There are several important basic principles for loading a sterilizer: allow for proper sterilant circulation perforated trays should be placed so the tray is parallel to the shelf nonperforated containers should be placed on their edge (e.g., basins) small items should be loosely placed in wire baskets and peel packs should be placed on edge in perforated or mesh bottom racks or baskets 454, 811, 836 .

    Studies in the early 1970s suggested that wrapped surgical trays remained sterile for varying periods depending on the type of material used to wrap the trays. Safe storage times for sterile packs vary with the porosity of the wrapper and storage conditions (e.g., open versus closed cabinets). Heat-sealed, plastic peel-down pouches and wrapped packs sealed in 3-mil (3/1000 inch) polyethylene overwrap have been reported to be sterile for as long as 9 months after sterilization. The 3-mil polyethylene is applied after sterilization to extend the shelf life for infrequently used items 967 . Supplies wrapped in double-thickness muslin comprising four layers, or equivalent, remain sterile for at least 30 days. Any item that has been sterilized should not be used after the expiration date has been exceeded or if the sterilized package is wet, torn, or punctured.

    Although some hospitals continue to date every sterilized product and use the time-related shelf-life practice, many hospitals have switched to an event-related shelf-life practice. This latter practice recognizes that the product should remain sterile until some event causes the item to become contaminated (e.g., tear in packaging, packaging becomes wet, seal is broken) 968 . Event-related factors that contribute to the contamination of a product include bioburden (i.e., the amount of contamination in the environment), air movement, traffic, location, humidity, insects, vermin, flooding, storage area space, open/closed shelving, temperature, and the properties of the wrap material 966, 969 . There are data that support the event-related shelf-life practice 970-972 . One study examined the effect of time on the sterile integrity of paper envelopes, peel pouches, and nylon sleeves. The most important finding was the absence of a trend toward an increased rate of contamination over time for any pack when placed in covered storage 971 . Another evaluated the effectiveness of event-related outdating by microbiologically testing sterilized items. During the 2-year study period, all of the items tested were sterile 972 . Thus, contamination of a sterile item is event-related and the probability of contamination increases with increased handling 973 .

    Following the sterilization process, medical and surgical devices must be handled using aseptic technique in order to prevent contamination. Sterile supplies should be stored far enough from the floor (8 to 10 inches), the ceiling (5 inches unless near a sprinkler head [18 inches from sprinkler head]), and the outside walls (2 inches) to allow for adequate air circulation, ease of cleaning, and compliance with local fire codes (e.g., supplies must be at least 18 inches from sprinkler heads). Medical and surgical supplies should not be stored under sinks or in other locations where they can become wet. Sterile items that become wet are considered contaminated because moisture brings with it microorganisms from the air and surfaces. Closed or covered cabinets are ideal but open shelving may be used for storage. Any package that has fallen or been dropped on the floor must be inspected for damage to the packaging and contents (if the items are breakable). If the package is heat-sealed in impervious plastic and the seal is still intact, the package should be considered not contaminated. If undamaged, items packaged in plastic need not be reprocessed.

    The sterilization procedure should be monitored routinely by using a combination of mechanical, chemical, and biological indicators to evaluate the sterilizing conditions and indirectly the microbiologic status of the processed items. The mechanical monitors for steam sterilization include the daily assessment of cycle time and temperature by examining the temperature record chart (or computer printout) and an assessment of pressure via the pressure gauge. The mechanical monitors for ETO include time, temperature, and pressure recorders that provide data via computer printouts, gauges, and/or displays 814 . Generally, two essential elements for ETO sterilization (i.e., the gas concentration and humidity) cannot be monitored in healthcare ETO sterilizers.

    Chemical indicators are convenient, are inexpensive, and indicate that the item has been exposed to the sterilization process. In one study, chemical indicators were more likely than biological indicators to inaccurately indicate sterilization at marginal sterilization times (e.g., 2 minutes) 847 . Chemical indicators should be used in conjunction with biological indicators, but based on current studies should not replace them because they indicate sterilization at marginal sterilization time and because only a biological indicator consisting of resistant spores can measure the microbial killing power of the sterilization process. 847, 974 . Chemical indicators are affixed on the outside of each pack to show that the package has been processed through a sterilization cycle, but these indicators do not prove sterilization has been achieved. Preferably, a chemical indicator also should be placed on the inside of each pack to verify sterilant penetration. Chemical indicators usually are either heat-or chemical-sensitive inks that change color when one or more sterilization parameters (e.g., steam-time, temperature, and/or saturated steam ETO-time, temperature, relative humidity and/or ETO concentration) are present. Chemical indicators have been grouped into five classes based on their ability to monitor one or multiple sterilization parameters 813, 819 . If the internal and/or external indicator suggests inadequate processing, the item should not be used 815 . An air-removal test (Bowie-Dick Test) must be performed daily in an empty dynamic-air-removal sterilizer (e.g., prevacuum steam sterilizer) to ensure air removal.

    Biological indicators are recognized by most authorities as being closest to the ideal monitors of the sterilization process 974, 975 because they measure the sterilization process directly by using the most resistant microorganisms (i.e., Bacillus spores), and not by merely testing the physical and chemical conditions necessary for sterilization. Since the Bacillus spores used in biological indicators are more resistant and present in greater numbers than are the common microbial contaminants found on patient-care equipment, the demonstration that the biological indicator has been inactivated strongly implies that other potential pathogens in the load have been killed 844 .

    An ideal biological monitor of the sterilization process should be easy to use, be inexpensive, not be subject to exogenous contamination, provide positive results as soon as possible after the cycle so that corrective action may be accomplished, and provide positive results only when the sterilization parameters (e.g., steam-time, temperature, and/or saturated steam ETO-time, temperature, relative humidity and/or ETO concentration) are inadequate to kill microbial contaminates 847 .

    Biological indicators are the only process indicators that directly monitor the lethality of a given sterilization process. Spores used to monitor a sterilization process have demonstrated resistance to the sterilizing agent and are more resistant than the bioburden found on medical devices 179, 911, 912 . B. atrophaeus spores (10 6 ) are used to monitor ETO and dry heat, and G. stearothermophilus spores (10 5 ) are used to monitor steam sterilization, hydrogen peroxide gas plasma, and liquid peracetic acid sterilizers. G. stearothermophilus is incubated at 55-60°C, and B. atrophaeus is incubated at 35-37°C. Steam and low temperature sterilizers (e.g., hydrogen peroxide gas plasma, peracetic acid) should be monitored at least weekly with the appropriate commercial preparation of spores. If a sterilizer is used frequently (e.g., several loads per day), daily use of biological indicators allows earlier discovery of equipment malfunctions or procedural errors and thus minimizes the extent of patient surveillance and product recall needed in the event of a positive biological indicator 811 . Each load should be monitored if it contains implantable objects. If feasible, implantable items should not be used until the results of spore tests are known to be negative.

    Originally, spore-strip biological indicators required up to 7 days of incubation to detect viable spores from marginal cycles (i.e., when few spores remained viable). The next generation of biological indicator was self-contained in plastic vials containing a spore-coated paper strip and a growth media in a crushable glass ampoule. This indicator had a maximum incubation of 48 hours but significant failures could be detected in £24 hours. A rapid-readout biological indicator that detects the presence of enzymes of G. stearothermophilus by reading a fluorescent product produced by the enzymatic breakdown of a nonfluorescent substrate has been marketed for the more than 10 years. Studies demonstrate that the sensitivity of rapid-readout tests for steam sterilization (1 hour for 132°C gravity sterilizers, 3 hrs for 121°C gravity and 132°C vacuum sterilizers) parallels that of the conventional sterilization-specific biological indicators 846, 847, 976, 977 and the fluorescent rapid readout results reliably predict 24- and 48-hour and 7-day growth 978 . The rapid-readout biological indicator is a dual indicator system as it also detects acid metabolites produced during growth of the G. stearothermophilusspores. This system is different from the indicator system consisting of an enzyme system of bacterial origin without spores. Independent comparative data using suboptimal sterilization cycles (e.g., reduced time or temperature) with the enzyme-based indicator system have not been published 979 .

    A new rapid-readout ETO biological indicator has been designed for rapid and reliable monitoring of ETO sterilization processes. The indicator has been cleared by the FDA for use in the United States 400 . The rapid-readout ETO biological indicator detects the presence of B. atrophaeus by detecting a fluorescent signal indicating the activity of an enzyme present within the B. atrophaeus organism, beta-glucosidase. The fluorescence indicates the presence of an active spore-associated enzyme and a sterilization process failure. This indicator also detects acid metabolites produced during growth of the B. atrophaeus spore. Per manufacturer&rsquos data, the enzyme always was detected whenever viable spores were present. This was expected because the enzyme is relatively ETO resistant and is inactivated at a slightly longer exposure time than the spore. The rapid-readout ETO biological indicator can be used to monitor 100% ETO, and ETO-HCFC mixture sterilization cycles. It has not been tested in ETO-CO2 mixture sterilization cycles.

    The standard biological indicator used for monitoring full-cycle steam sterilizers does not provide reliable monitoring flash sterilizers 980 . Biological indicators specifically designed for monitoring flash sterilization are now available, and studies comparing them have been published 846, 847, 981 .

    Since sterilization failure can occur (about 1% for steam) 982 , a procedure to follow in the event of positive spore tests with steam sterilization has been provided by CDC and the Association of periOperative Registered Nurses (AORN). The 1981 CDC recommendation is that &ldquoobjects, other than implantable objects, do not need to be recalled because of a single positive spore test unless the steam sterilizer or the sterilization procedure is defective.&rdquo The rationale for this recommendation is that single positive spore tests in sterilizers occur sporadically. They may occur for reasons such as slight variation in the resistance of the spores 983 , improper use of the sterilizer, and laboratory contamination during culture (uncommon with self-contained spore tests). If the mechanical (e.g., time, temperature, pressure in the steam sterilizer) and chemical (internal and/or external) indicators suggest that the sterilizer was functioning properly, a single positive spore test probably does not indicate sterilizer malfunction but the spore test should be repeated immediately 983 . If the spore tests remain positive, use of the sterilizer should be discontinued until it is serviced 1 . Similarly, AORN states that a single positive spore test does not necessarily indicate a sterilizer failure. If the test is positive, the sterilizer should immediately be rechallenged for proper use and function. Items, other than implantable ones, do not necessarily need to be recalled unless a sterilizer malfunction is found. If a sterilizer malfunction is discovered, the items must be considered nonsterile, and the items from the suspect load(s) should be recalled, insofar as possible, and reprocessed 984 . A suggested protocol for management of positive biological indicators is shown in Table 12 839 . A more conservative approach also has been recommended 813 in which any positive spore test is assumed to represent sterilizer malfunction and requires that all materials processed in that sterilizer, dating from the sterilization cycle having the last negative biologic indicator to the next cycle showing satisfactory biologic indicator challenge results, must be considered nonsterile and retrieved, if possible, and reprocessed. This more conservative approach should be used for sterilization methods other than steam (e.g., ETO, hydrogen peroxide gas plasma). However, no action is necessary if there is strong evidence for the biological indicator being defective 983 or the growth medium contained a Bacillus contaminant 985 .

    If patient-care items were used before retrieval, the infection control professional should assess the risk of infection in collaboration with central processing, surgical services, and risk management staff. The factors that should be considered include the chemical indicator result (e.g., nonreactive chemical indicator may indicate temperature not achieved) the results of other biological indicators that followed the positive biological indicator (e.g., positive on Tuesday, negative on Wednesday) the parameters of the sterilizer associated with the positive biological indicator (e.g., reduced time at correct temperature) the time-temperature chart (or printout) and the microbial load associated with decontaminated surgical instruments (e.g., 85% of decontaminated surgical instruments have less than 100 CFU). The margin of safety in steam sterilization is sufficiently large that there is minimal infection risk associated with items in a load that show spore growth, especially if the item was properly cleaned and the temperature was achieved (e.g., as shown by acceptable chemical indicator or temperature chart). There are no published studies that document disease transmission via a nonretrieved surgical instrument following a sterilization cycle with a positive biological indicator.

    False-positive biological indicators may occur from improper testing or faulty indicators. The latter may occur from improper storage, processing, product contamination, material failure, or variation in resistance of spores. Gram stain and subculture of a positive biological indicator may determine if a contaminant has created a false-positive result 839, 986 . However, in one incident, the broth used as growth medium contained a contaminant, B. coagulans,which resulted in broth turbidity at 55°C 985 . Testing of paired biological indicators from different manufacturers can assist in assessing a product defect 839 . False-positive biological indicators due to extrinsic contamination when using self-contained biological indicators should be uncommon. A biological indicator should not be considered a false-positive indicator until a thorough analysis of the entire sterilization process shows this to be likely.

    The size and composition of the biological indicator test pack should be standardized to create a significant challenge to air removal and sterilant penetration and to obtain interpretable results. There is a standard 16-towel pack recommended by AAMI for steam sterilization 813, 819, 987 consisting of 16 clean, preconditioned, reusable huck or absorbent surgical towels each of which is approximately 16 inches by 26 inches. Each towel is folded lengthwise into thirds and then folded widthwise in the middle. One or more biological indicators are placed between the eight and ninth towels in the approximate geometric center of the pack. When the towels are folded and placed one on top of another, to form a stack (approximately 6 inch height) it should weigh approximately 3 pounds and should have a density of approximately 11.3 pounds per cubic foot 813 . This test pack has not gained universal use as a standard pack that simulates the actual in-use conditions of steam sterilizers. Commercially available disposable test packs that have been shown to be equivalent to the AAMI 16 towel test pack also may be used. The test pack should be placed flat in an otherwise fully loaded sterilizer chamber, in the area least favorable to sterilization (i.e., the area representing the greatest challenge to the biological indicator). This area is normally in the front, bottom section of the sterilizer, near the drain 811, 813 . A control biological indicator from the lot used for testing should be left unexposed to the sterilant, and then incubated to verify the presterilization viability of the test spores and proper incubation. The most conservative approach would be to use a control for each run however, less frequent use may be adequate (e.g., weekly). There also is a routine test pack for ETO where a biological indicator is placed in a plastic syringe with plunger, then placed in the folds of a clean surgical towel, and wrapped. Alternatively, commercially available disposal test packs that have been shown to be equivalent to the AAMI test pack may be used. The test pack is placed in the center of the sterilizer load 814 . Sterilization records (mechanical, chemical, and biological) should be retained for a time period in compliance with standards (e.g., Joint Commission for the Accreditation of Healthcare Facilities requests 3 years) and state and federal regulations.

    In Europe, biological monitors are not used routinely to monitor the sterilization process. Instead, release of sterilizer items is based on monitoring the physical conditions of the sterilization process that is termed &ldquoparametric release.&rdquo Parametric release requires that there is a defined quality system in place at the facility performing the sterilization and that the sterilization process be validated for the items being sterilized. At present in Europe, parametric release is accepted for steam, dry heat, and ionizing radiation processes, as the physical conditions are understood and can be monitored directly 988 . For example, with steam sterilizers the load could be monitored with probes that would yield data on temperature, time, and humidity at representative locations in the chamber and compared to the specifications developed during the validation process.

    Periodic infection control rounds to areas using sterilizers to standardize the sterilizer&rsquos use may identify correctable variances in operator competence documentation of sterilization records, including chemical and biological indicator test results sterilizer maintenance and wrapping and load numbering of packs. These rounds also may identify improvement activities to ensure that operators are adhering to established standards. 989


    To figure out how to clean sex toys, you’ll need to know exactly what they’re made of.

    You might think you can just dunk your sex toys in soap and water and be done with it. Please don’t do that. Instead, the first step in cleaning a sex toy is figuring out what material the toy is made of. You can divide most sex toys into two broad categories: porous materials and nonporous materials.

    If the material is porous, it has tiny holes (like pores) that can harbor bacteria, fungi, and general gunk, Lisa Finn, a sex educator at the sex toy boutique Babeland, tells SELF.

    According to Finn, porous materials include:

    Elastomer (rubber) varieties, like:

    Thermoplastic rubber, or TPR for short sometimes called “skin-safe rubber”

    Thermoplastic elastomer, a.k.a. TRE also sometimes called “skin-safe rubber”

    Jelly rubber sometimes (not always) contains phthalates, a group of chemicals that have come under fire for their potential to affect human health (the scientific jury is still out, according to the National Library of Medicine)

    -Polyvinyl chloride (PVC) also sometimes contains phthalates

    Materials like Sensafirm and UR3, which can help toys feel like skin

    Latex, which isn’t regulated by the Food and Drug Administration in sex toys the way it is in condoms

    If your sex toy is made from nonporous materials, it doesn’t have those holes, so various microorganisms are less likely to stick around. And here are common nonporous sex-toy materials:

    Acrylonitrile butadiene styrene (ABS) plastic (a kind of hard plastic)

    Borosilicate glass (as in Pyrex and similar varieties)

    Soda-lime glass (like the kind used for drinking glasses)

    Metals like stainless steel and gold

    To find out what kind of material your toy is made of, check the box or look it up online. It’s worth noting right off the bat that even if you clean your porous sex toys, you might not be able to remove as many germs as you’d be able to with nonporous ones, so it’s best to save them for personal play or use them with condoms for partnered fun—more on that in a bit.


    Best disinfecting cleaner for pet messes

    Clorox Pet Solutions Stain & Odor Remover is tough on deep-rooted stains but gentle and safe to use around dogs, cats, and other household pets.

    Pros: Effectively removes stains, safe to use around pets, bleach and fragrance-free, helps to prevent re-soiling

    Cons: Must purchase a spray bottle, not recommended for brass or natural marble surfaces

    Clorox Pet Solutions Stain & Odor Remover is effective at removing tough pet messes like drool, feces, urine, and vomit, and it's safe to use around your furry friends (as long as you take a few precautions). "It's fine to use a regular disinfectant or bleach on bowls or pet toys with hard surfaces — you'll just want to rinse the surfaces with water after they've dried," Sansoni said. For more information on pet-safe products, check out our FAQ.

    Simply pour the solution into a reusable spray bottle to clean pet bedding, carpets, clothing, flooring, furniture, travel crates, and upholstery. Then allow it to sit for five to 10 minutes before rinsing or wiping the area down with a clean, damp cloth. It's bleach- and fragrance-free and wonderful at eliminating odors that tend to stubbornly linger. Regularly using this disinfectant may help your pet remember not to go back to re-soil the same spot.

    Brian Sansoni, SVP of Communication at the American Cleaning Institute, gave us some helpful information on assessing the quality of a disinfectant.

    What ingredients should I look for in a disinfectant?

    Sansoni said that some of the more active ingredients found within disinfectant cleaners include sodium hypochlorite, ethanol, pine oil, hydrogen peroxide, citric acid, and quats, otherwise known as quaternary ammonium compounds. For efficacy, be sure to visit the manufacturer's website, look for the product in SmartLabel (a digital shopping tool where you can find detailed info that won't fit on your standard cleaning product's packaging), and check out the American Cleaning Institute's guide on how to read a product label.

    In addition to the ingredients listed above, your disinfectant of choice may include a combination of surfactants, builders, solvents, enzymes, fragrances, preservatives, pH adjusters, and thickeners or foam enhancers.

    Do disinfecting cleaners kill the coronavirus?

    There are a number of disinfectant products that can be effective against the coronavirus on hard, nonporous surfaces, in accordance with the EPA Viral Emerging Pathogen Policy. Visit EPA-registered disinfectant products to use against Novel Coronavirus (COVID-19) for more information.

    Will alcohol kill germs?

    Alcohol solutions need to contain at least 70% alcohol to be effective on hard surfaces against the coronavirus. Read the labels on alcohol-based products, and be sure to reach for isopropyl alcohol and not ethanol, which is used in cocktails and other alcoholic beverages.

    You'll want to pre-clean the surface with soap and water. Then, apply the alcohol solution to the surface — without diluting it — and let it air dry for at least 30 seconds before wiping.

    It's important to never mix isopropyl alcohol or rubbing alcohol — which is typically 70% isopropyl alcohol and 30% water — with bleach since it will create chloroform, which is toxic.

    What surfaces can I use rubbing alcohol or isopropyl alcohol on?

    Rubbing alcohol and isopropyl alcohol can liquify and damage finished surfaces since isopropyl alcohol is a solvent. Sansoni advises against using either on painted, shellacked, lacquered, or varnished surfaces, including treated wood.

    However, rubbing alcohol can be a great stain treatment for certain fabrics and can remove ink, grass, grease, or sap. While it's good for carpet, Sansoni doesn't recommend rubbing alcohol on materials like acetate, rayon, wool, and silk.

    Do all-purpose cleaners kill germs?

    A traditional all-purpose cleaner is designed to lift dirt off of surfaces, but it won't completely disinfect the area you're cleaning. Stick with a disinfectant designed to kill bacteria and germs. Keep in mind, however, that disinfectants won't make surfaces shine like an all-purpose cleaner. Popular all-purpose cleaners that aren't disinfectants include Mrs. Meyer's Clean Day Multi-Surface Cleaner and Everspring's Lemon & Mint All-Purpose Cleaner.

    Will hydrogen peroxide kill germs?

    Some registered disinfectants contain hydrogen peroxide as the active ingredient. The typical 3% hydrogen peroxide concentration found at drugstores can be used to disinfect surfaces. Pre-clean the surface before applying the liquid, and then let it air dry for at least a minute before wiping.

    If you're using a cleaner that contains hydrogen peroxide, check the product label for instructions on how long the cleaner needs to sit on the surface before wiping. Never mix hydrogen peroxide with vinegar, bleach, or other cleaners.

    Will vinegar kill germs?

    While vinegar has bacteria-killing properties, it is not listed as an EPA-approved disinfectant.

    Do "eco-friendly" or "natural" cleaners work as well as ones with more "powerful" chemicals?

    "Eco-friendly" and "natural" are, more often than not, marketing terms rather than scientific ones. It all comes down to how the product is formulated, what ingredients it contains, and preference. When a product is labeled as "natural," it typically means that it's void of harmful chemicals.

    What makes a cleaning product "pet-safe"?

    According to Sansoni, products that are labeled as "pet-safe" are usually formulated with ingredients that are less harmful when unintentionally ingested.

    It's important to note that cleaning products are safe for people and pets when used as intended. However, because pets have a habit of putting their mouths on things they're not supposed to, the added step of rinsing any leftover product off of surfaces can be helpful.

    What is an odor eliminator?

    An odor eliminator can either cover up an odor, absorb it, or kill odor-causing germs. Fragrances that cover an odor may be used in tandem with an odor absorber or a product that kills odor-causing bacteria. Some odor-eliminating sprays use compounds called cyclodextrins to trap odor molecules.

    We've rounded up the best odor eliminators for your home.

    Are wipes better than sprays?

    This is a matter of preference. Some spray products may be available in a wipe version or vice versa, with some customers finding that one product is able to reach the space they want to clean better than the other. Sansoni mentioned there isn't a benefit for letting a disinfectant stay on surfaces longer than recommended, and you should always follow the instructions on the label.


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