Washing your hands regularly is one of the first things that public health officials in Canada, the U.S. and the World Health Organization recommend in their online resources on preventing the spread of COVID-19.
“You can stay healthy and prevent the spread of infections by … washing your hands often with soap and water for at least 20 seconds,” says the Canadian government’s website.
“Individuals can practice everyday prevention measures like frequent hand washing, staying home when sick, and covering coughs and sneezes,” says the Centers for Disease Control’s page on how to prevent COVID-19 spread in communities.
In outlining “basic” measures in protecting oneself against the new virus, the WHO’s first tip is to “wash your hands frequently.”
So what exactly is it about handwashing that’s so effective?
A tweet by one biophysicist in the U.S. went viral recently when it pointed out the simple mechanics behind handwashing and its effect on a virus like the novel coronavirus.
Emphasizing that she is not a health-care worker and not dispensing health-care advice, Karen Fleming from Johns Hopkins University said she didn’t expect her short Twitter thread to go viral.
As she explained in an email to Global News on Sunday night, she and her co-workers were “chatting about the new virus last week and realized that it was ‘enveloped.’”
“When viruses are enveloped, it means that they have an outer most wrapper that’s basically a fatty, greasy outer covering,” Fleming wrote on Twitter.
That outer covering — a membrane bilayer — is “just grease.”
“And we all know that soaps and detergents can dissolve grease, so that means soap/detergents can also dissolve the outer viral envelopes of coronaviruses like COVID-19,” she said.
She tweeted out this fact because experience has shown her that students tend to learn better if they’re told the value of their knowledge.
“I realized that laypersons might not understand the value of the recommendation from the U.S. CDC to ‘wash your hands,’” Fleming said.
“It kind of sounds like a generic statement that your mother would make.”
So essentially, washing your hands achieves two goals: removing dirt, grime and germs is the first. The second is that the soap “can disrupt and dissolve” the greasy outer layer of enveloped viruses, “which inactivates them, hence killing them,” according to Fleming.
“I thought this second aspect was something most non-science people would not know about, and that learning this factoid might help the ‘wash your hands’ recommendation be taken more seriously,” she said.
Jason Tetro, microbiologist and host of the Super Awesome Science Show podcast, likened it to washing your dishes after getting them greasy.
How many times a person usually washes their hands can vary, Tetro said.
“The most important thing is that if your hands have touched a surface or have been in an environment where you cannot tell what the microbial composition probably is, then it’s a very good likelihood that you want to wash your hands,” he said.
Canada’s chief public health officer Dr. Theresa Tam regularly tweets about the importance of frequent handwashing as well as other tips to prevent the spread of COVID-19.
Other recommendations include coughing and sneezing into your elbow and avoiding touching your face.
The WHO also advises keeping a distance of at least three feet between yourself and a person who is coughing or sneezing, to prevent exposure to droplets: “When someone coughs or sneezes they spray small liquid droplets from their nose or mouth which may contain virus.”
The new coronavirus was first reported in Wuhan, China.