How likely is it that COVID is transmitted through surfaces?
While the dawn of the pandemic seems like a lifetime ago, it is also unforgettable. Suddenly, a mysterious and terrifying new virus was taking over the entire world, prompting everyone to scramble whatever was available to make masks, obsessively sanitize their hands, and clean food as soon as they brought it home.
There is no question that mask wearing and sanitizing are important in stopping the spread of COVID. But two years later, most people have stopped cleaning surfaces as often as before. But new research You may want to order disinfecting wipes in bulk one more time. According to scientists who carried out tests for the Food Standards Agency (FSA), the COVID virus can remain on some surfaces in supermarkets for days.
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For the study, scientists deliberately placed the COVID virus on food containers for beverages, cakes, fruit, canned goods, beverage cartons, and other items. After 24 hours, they found a significant drop in COVID particles in the packaging. However, they continued to find traces of the virus on certain surfaces several days later.
How worrisome are these findings? Here, three infectious disease doctors weigh in.
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How COVID can spread through surfaces
First, a bit of the spread of COVID-101 as far as surfaces are concerned. After all, it may have been a couple of years since he thought of the virus in this way. “COVID spreads once its viral particles reach the surface. If they survive long enough and come into contact with the hands or mouth, they eventually transfer to the mucosa, covering the inside of the mouth, where they then infect the body,” he explains. Dr. Roger Seheult, M.D., medical adviser of Rapid On/Go COVID Test producer I enterclinical associate professor at the University of California Riverside School of Medicine, and clinical assistant professor at the Loma Linda University School of Medicine and Allied Health.
“SARS-CoV-2, the virus that causes COVID, can be spread by touching a surface that has been contaminated with the virus and then touching your mouth, nose or eyes,” he says. Dr. Meghan Baker, MD, ScD, assistant professor in the Department of Population Medicine at Harvard Medical School. Here’s what this might look like, hypothetically speaking: someone with COVID might cover their mouth when they cough and then use their hands to sort through some oranges at the grocery store, selecting a few to take home. Later, someone else comes along and touches the same oranges that were touched. Then they absentmindedly bite their nails as they wait in line to pay. If they picked up COVID particles from the oranges, putting your fingers in your mouth could potentially lead to contracting the virus.
Dr. Seheult says that contracting the COVID virus from a surface requires that the spike protein (which binds to receptors on target cells) and other proteins on the surface of the virus remain intact and functional, something that can quickly break down depending on the virus. of the nature of the surface and the time spent there. That’s why the researchers found that COVID particles on surfaces dropped dramatically after 24 hours.
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How concerned should we be about contracting COVID by touching surfaces?
While the new study may be alarming, infectious disease doctors say it’s not something we should be overly concerned about. “COVID is not primarily spread through surfaces,” says Dr. Baker. “Most of the transmission is by inhalation of respiratory aerosols.” (For example, if you are having a conversation with someone with COVID and the particles travel from their mouth through the air to your own mouth.)
Dr. Monica Gandhi, MD, MPH, the associate division chief in the Division of HIV, Infectious Diseases and Global Medicine at UCSF/San Francisco General Hospital, also says that COVID is not primarily transmitted through surfaces. “We do not believe that COVID is spread by touching surfaces, despite this new report that researchers inoculated food or food packages with live SARS-CoV-2 virus and then cultured and recovered the virus from those inoculated surfaces.” , he says. “The report describes an artificial situation in which researchers smeared surfaces with viruses; which is not likely to happen in real life lifetime and under the conditions of a typical visit to a grocery store.”
Dr. Gandhi points to previous research showing that transmission of the virus through indirect contact (such as touching a surface that someone with COVID previously touched) is unlikely. For example, in a study, The researchers took samples from surfaces in hospitals touched by patients who tested positive for COVID. The swabs did not pick up any virus particles. Other studies had similar results. “Many routine sanitizing rituals, including the ubiquitous use of alcohol-based hand sanitizers and excessive use of harsh cleaning products, are unnecessary,” says Dr. Gandhi.
In fact, Dr. Gandhi says there are times when excessive disinfection can be dangerous. For example, someone may wash their food products with bleach or household cleaning products in an effort to protect themselves from COVID and could end up consuming harmful particles from these cleaning agents later while eating the food.
“Based on previous dataExperts believe that around a thousand viral particles are needed to successfully cause an infection,” says Dr. Seheult, also speaking of the improbability of contracting COVID via surfaces. “As the number of particles is transferred to a surface, it is possible that some are viable enough to infect a person, but it becomes less likely when fewer than a thousand particles are ultimately transmitted. Your body has defense mechanisms that can quickly shut down an infection, so for the virus to successfully cause an infection, it has to get past that initial step.”
Rather than obsess over the lifespan of COVID on surfaces, doctors say what would be more helpful is to be diligent about getting vaccinated and boosted. Wearing a mask and regularly using hand sanitizer can also help prevent illness, not just from COVID but from other illnesses this winter. “Focus on hand hygiene and not touching your eyes, nose or mouth,” says Baker. “I would prioritize cleaning high-touch surfaces and surfaces in areas with a higher density of people at high risk of severe illness, to help protect those people from infection.”
If you put all of this into practice, you really are doing what you can to better protect yourself and others.
Then, Find out how COVID vaccines and boosters might be different in the future than they are now.
- Dr. Roger Seheult, M.D.medical adviser of Rapid On/Go COVID Test producer I enterAssociate Clinical Professor at the University of California Riverside School of Medicine and Assistant Clinical Professor at the Loma Linda University School of Medicine and Allied Health
- Dr. Meghan Baker, MD, ScD, assistant professor in the Department of Population Medicine, Harvard Medical School
- Dr. Monica Gandhi, MD, MPH, associate division chief in the Division of HIV, Infectious Diseases and Global Medicine at UCSF/San Francisco General Hospital