Is it time to ditch disinfecting? CDC updates data surrounding COVID-19 surface transmission

Are you sanitizing every single surface you could possibly touch, multiple times a day? A recent CDC brief may have you rethinking your practices.

If you look back at the past year, how much of your time has been dedicated to disinfecting alone?

Minutes? Hours? Days?

Well some recent CDC data seems to suggest the tedious chore is no longer worthy of your time.

According to a science brief released in early April, your chances of contracting COVID-19 from a surface (called fomite transmission) in an indoor community are low — less than 1 in 10,000.

Dr. Joseph Blondeau says it’s important to acknowledge that the data has some limitations.

“ acknowledge some of the difficulties in investigating this area… that it’s difficult to document that someone had received an infection from a fomite transmission,” said Blondeau, head of clinical microbiology at Royal University Hospital.

The brief says fomite transmission depends on several different variables, including how much virus is on the surface, how long it has been sitting there, whether or not it’s been exposed to a cleaning agent, heat, or ventilation. It’s also difficult to prove that fomite transmission has occurred, according to the CDC, because respiratory transmission cannot be ruled out.

“I’m not surprised that they would actually come out and say that transmission from fomite is relatively low risk,” said Blondeau.

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The brief also breaks down how long COVID-19 particles can survive on a surface.

On a porous surface, COVID-19 particles can be detected for minutes or hours.

On a non-porous surface such as stainless steel, glass, or plastic, the virus can be detected for days or weeks.

However, the brief highlights that within three days, 99 per cent of infectious particles on the surface break down under regular indoor conditions, even if the surface hasn’t been cleaned, though the CDC says these studies do not necessarily reflect real-world conditions.

“One has to imagine that the contact has to really occur relatively soon,” said Ralph Pantophlet, associate professor with the Faculty of Health Sciences at Simon Fraser University.

But even if the contact happens, it doesn’t mean you’ll get sick, says Pantophlet. For that, your soiled hands would have to touch your eyes, nose, or mouth.

This is why Stacey Smith? emphasizes that frequent handwashing should remain part of our routine, even if chances of the virus being on a surface are low.

“Although the virus can sit on a door handle, it tends not to live very long,” said Smith?, a professor in the School of Epidemiology and Public Health at the University of Ottawa. “The simple answer is viruses need moist environments, and your hands are moist environments.”

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The CDC guidelines say cleaning a high-touch surface with detergent or soap once a day is enough, if there hasn’t been a suspected or confirmed COVID-19 case in the area within 24 hours.

If there has, you’d need to clean with a disinfectant.

So, should we just cut down on the daily overzealous disinfecting?

Blondeau says this may be too risky.

“Even if it’s a low risk of transmission from a fomite, it’s not zero,” he said.

“We’re at a point in time right now where we still have a very vulnerable part of our population, and we have variants of concern that are spreading across the country… my own personal opinion would be is that this is not the time to relax some of these recommendations.”

Meanwhile, Pantophlet says it would be helpful to wait and hear from Health Canada about this. The agency’s guidelines still recommend individuals to “frequently clean” high-touch surfaces in their homes or public spaces.

In the meantime, Pantophlet says individuals can assess the present risk in a given situation before deciding to disinfect. Has the surface you’re about to touch been cleaned recently? Do the people in this enclosed space frequently wear masks, or are they spewing their droplets everywhere?

“It’s not a ‘one size fits all,'” he said.

Smith? says washing or disinfecting 20 times may have never been great in the first place, since it exhausts the energy we need to keep up with other important measures, such as physical distancing. That’s why she says it’s best to focus on mitigating our risk based on the modes of transmission that are most proven — direct contact, respiratory droplets, and airborne transmission.

This means focusing our energy on staying home, not coming into close contact with those outside our household, and avoiding indoor gatherings.

Smith? also stresses that the CDC’s new disinfecting guidelines can be applied to areas like a small office space or a home. However, high-traffic environments such as a hospital need to continue to disinfect frequently, since the potential of an infectious particle to be present on a surface is multiplied.

© 2021 Global News, a division of Corus Entertainment Inc.

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