When the coronavirus started spreading in the United States last spring, many experts warned about the danger posed by surfaces. Researchers have reported that the virus can survive for days on plastic or stainless steel, and the Centers for Disease Control and Prevention has advised that if someone touches one of these infected surfaces – and then touches their eyes, nose or mouth – they can become infected.
Americans responded in kind, wiped out groceries, quarantined mail, and cleaned the shelves of Clorox wipes. Facebook has closed two of its offices for ‘deep cleaning’. The New York Metropolitan Transportation Authority began disinfecting subway cars every night.
But the era of “hygiene theater” may have ended unofficially this week, when the CDC updated its surface cleaning guidelines and noted that the risk of contracting a virus by touching an infected surface is less than 1 out of 10,000 was.
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“People can be affected by the virus that causes COVID-19 through contact with infected surfaces and objects,” said Dr. Rochelle Walensky, the director of the CDC, said at an information session in the White House on Monday. “However, evidence has shown that the risk of transmission infection is actually low.”
The recognition is long overdue, scientists say.
“Finally,” said Linsey Marr, an expert on air viruses at Virginia Tech. “We have known this for a long time and yet people still focus so much on cleaning the surface.” She added: “There is actually no evidence that anyone ever got COVID-19 by touching an infected surface.”
During the early days of the pandemic, many experts believed that the virus spread mainly through large respiratory droplets. These droplets are too heavy to travel long distances through the air, but can fall on objects and surfaces.
In this context, it seems sensible to scrub off every surface. “Surface cleaning is more well known,” Marr said. “We know how to do it. You can see how people do it, and you see the clean surface. And so I think, it makes people feel safer. ”
But in recent years it has become increasingly clear that the virus spreads mainly through the air – in both large and small droplets, which can stay up longer – and that barn door handles and metro seats do nothing to keep people safe.
“The scientific basis for all this concern about surfaces is very slim – slim to none,” said Emanuel Goldman, a microbiologist at Rutgers University. He wrote last summer that the risk of surface transfer was exceeded. ‘It’s a virus that you get by breathing. It’s not a virus that affects you by touching it. ”
The CDC has previously acknowledged that surfaces are not the primary way the virus spreads. But the agency’s statements this week went further.
“The most important part of this update is that they clearly communicate the correct, low risk of surfaces to the public. This is not a message that has been clearly communicated over the past year,” said Joseph Allen, a building safety expert. . at the Harvard TH Chan School of Public Health.
Capturing the virus from surfaces remains theoretically possible, he noted. But it requires a lot of things to go wrong: a lot of fresh, infectious viral particles have to be deposited on the surface, and then a relatively large amount of it is quickly transferred to someone’s hand and then to their face. “The presence on a surface is not equal to the risk,” Allen said.
In most cases, cleaning with simple soap and water is enough to keep the chance of surface transfer low, except for hand washing and mask wear, according to the updated CDC cleaning guidelines. In most everyday scenarios and environments, people do not have to use chemical disinfectants, the agency says.
“I think it’s very helpful to tell what we do not have to do,” said Donald Milton, an aerosol scientist at the University of Maryland. “It is very useful to spray and irrigate a lot of chemicals.”
However, the guidelines do indicate that if those taking COVID-19 were in a specific room on the last day, the area should be cleaned and disinfected.
“Disinfection is only recommended in indoor environments – schools and homes – where there has been a suspected or confirmed case of COVID-19 in the past 24 hours,” Walensky said during the White House briefing. “In most cases, irrigation, fumigation and wide or electrostatic spraying are not recommended as a primary disinfection method, and it has several safety risks to consider.”
And the new cleaning guidelines do not apply to healthcare facilities, which require more intensive cleaning and disinfection.
Saskia Popescu, an epidemiologist at Infectious Diseases at George Mason University, said she was pleased to see the new guidance, which “reflects our evolving data on transmission through the pandemic.”
But she noted that it remains important to clean regularly – and maintain good handwashing practices – to reduce the risk of not only contracting the coronavirus, but also any other pathogens that may linger on a specific surface.
Allen said the school and business officials he spoke to this week expressed relief over the updated guidelines, which would allow them to withdraw from their intensive cleaning programs. “It frees up a lot of organizations to spend the money better,” he said.
Schools, businesses and other institutions that want to protect people need to shift their attention from surfaces to air quality, and invest in improved ventilation and filtration.
“This should be the end of deep cleaning,” Allen said, noting that the wrong focus on surfaces involves real costs. ‘This has led to closed playgrounds, it has led to nets being removed from basketball courts, and to books being quarantined in the library. This led to the whole missed school days for deep cleaning. As a result, you could not share a pencil. So it’s all the hygiene theater, and it’s a direct result of the non-transfer of surface transfer as a low risk. ”
This article originally appeared in The New York Times.
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