Why you probably still shouldn't worry about surface transmission of the coronavirus
TORONTO -- The consensus among health experts has been that the public shouldn’t be too worried about catching the virus that causes COVID-19 through surface contact.
But with the SARS-CoV-2 variants becoming more widespread, is this still the case?
Dr. Dominik Mertz, who is an associate professor in McMaster University’s Department of Medicine and director of its division of infectious diseases, told CTVNews.ca on Tuesday morning over the phone that the risk of surface transmission of the virus continues to be very low.
“I think we’ve learned since the very beginning that more of that surface transmission isn’t as important as we initially have assumed, just based on the fact that we didn’t know an awful lot about the virus when it all started,” said Mertz. “I would say that by the beginning of spring, end of summer, we started to realize that surfaces in particular are probably quite negligible of a risk.”
That low level of risk appears to still be the case today, despite the spread of the new virus variants, which have been far more infectious than the original strain.
“There’s certainly concerns that they spread more easily,” said Mertz.
Because the chance of surface transmission is already so low, the new variants don’t make much of a difference.
“Let’s say (a variant) increases the risk of transmission by 50 per cent. If the baseline risk of getting infected through a surface is at, let’s say one per cent as an arbitrary number … it doesn’t make an awful lot of difference that it’s now at 1.5 per cent,” Mertz explained.
But while the risk remains low, Mertz says it’s been difficult for health experts to communicate this to the public.
“The challenge is that … nobody would say it’s zero risk. And I keep saying, whatever we do, unless we hide in one room and don’t have contact with anything, it won’t be zero risk,” said Mertz. “But in my mind, it’s a negligible risk.”
To add to the confusion, numerous studies have made headlines, finding that the coronavirus could be viable on surfaces for hours and sometimes days. For example, a study published last month found that virus could survive on some fabrics for 72 hours. In October, another study found that the virus could survive on bank notes for at least 28 days.
“They’re very concerning studies, let me put it that way,” said Mertz.
Mertz says these studies are often conducted only in a controlled laboratory environment and don’t necessarily reflect how the virus spends in the real world.
“Will that potentially viable virus on that surface eventually result in infections? We don’t have the evidence that it happens,” he said. “That means it probably happens very rarely but it’s nothing that we would be able to pick up as a very important mode of transmission.
That means you purchased something from a store in-person, Mertz says you probably don’t need to wipe it down with Lysol.
“If you are out and about and you are touching a lot of things where someone might have sneezed on or whatever, just clean your hands afterwards,” said Mertz “As long as you clean your hands before you touch your mouth and eyes, nothing is going to happen. It doesn’t matter how contaminated the surface would potentially be."