An ongoing study suggests the novel COVID can live on human skin for as long as nine hours, yet experts say those findings aren’t as disturbing as they sound.
The study by Japanese researchers, published earlier this month in the science journal Clinical Infectious Diseases, looked at how long viruses can survive on human skin based on samples collected from cadavers about a day after death.
The findings suggest that the virus that causes COVID-19, SARS-CoV-2, can remain active for 9.04 hours — nearly five times longer than the survival time of the pathogen that causes the flu.
The study also indicated that an 80 percent ethanol-based sanitizer can kill the novel COVID in only 15 seconds.
Cynthia Carr, an epidemiologist in Winnipeg, says that is her main takeaway from the study.
“It’s a significant public health message to remind individuals that even though the virus can last essentially a full workday in a lab setting, you can quickly get rid of it if you just wash your hands,” she said.
“It’s not about panicking and having a full-body shower each time you return home. It’s about remembering that if the infection is on your hand and you wipe your nose or put your fingers in your mouth, that is where the opportunity is to get infected.”
Colin Furness, a disease control epidemiologist at the University of Toronto, says individuals are less likely to contract COVID-19 from touching a surface than from having close contact with an infected individual.
He suspects the reason for that has to do with the viral dose on surfaces versus that in droplets or aerosols. Coming into contact with a small viral load on a surface likely won’t result in severe infection, he says, adding that our bodies may fight off a very mild case without us even realizing we have it.
“I don’t think (this study) is anything we need to be too concerned about,” Furness said. “If it were, clinically we would be seeing that touch matters a lot more. And we’re not.”
Furness says public health strategies over the last few months have emphasized mask-wearing and avoiding gatherings “because they matter more.”
In any case, even somebody who’s asymptomatic or mildly symptomatic can transmit the infection, so Furness says it’s as yet critical to wash your hands consistently.
“I don’t want anyone thinking that touch doesn’t matter at all. You can still pick up the virus from touch,” Furness said. “And you can pick up a different virus during COVID that weakens your body, and then if you do get COVID you can have a worse outcome.”
The specialists state it’s also important to remember that studies done in lab settings, under completely controlled conditions, don’t really mean the rest of the world.
Carr said the study in Japan was done in warm, humid conditions, which the infection is known to thrive in.
Using skin samples from immobile cadavers could also play a role in how long the infection stayed on that surface, she included.
“My understanding is that the infection is relatively fragile,” Carr said. “So I don’t know how long it would be detectable on your hand in a genuine circumstance where you’re moving around.”
Plenty of lab studies have been conducted since the pandemic started indicating how long the novel COVID can survive on various surfaces. Another ongoing one found the infection could live on banknotes for as long as 28 days.
But Furness says to take that with a grain of salt.
“It’s almost like a little perverse competition to see who can keep COVID alive the longest, and I don’t think that is fair,” he said. “Saying it can survive on a banknote for a few days _ OK when the banknote is in the dark not being disturbed, and with wonderful stickiness, etc. That is the point at which it turns into somewhat dodgy.”
And detecting the infection on a surface isn’t same to deciding if it’s sufficiently able to taint somebody, Carr warned.
“That’s where we have a lack of knowledge,” she said. “It could be (detectable) for nine hours, six hours, 12 hours, but again the main take-away for me is how quickly it can be eradicated if you just wash your hands.”
For Furness, the interesting part of the Japan study was its comparison to the regular flu infection, which lasted on average slightly less than two hours on skin surfaces.
He says that may provide a potential clue as to why the novel coronavirus is so transmissible.
“It sheds a little bit of light on the way that this is a tough customer, that this is a relatively hardy virus compared to flu,” he said. “Also, it would help explain why this is quite a lot more infectious than something like flu.”
This news originally posted on globalnews.ca