Beyond the Bulletin interviews microbiologist Trevor Charles about COVID-19 on surfaces

Tuesday, May 26, 2020

Trevor Charles, a professor from the Department of Biology and Director of the Waterloo Centre for Microbial Research, visited the Beyond the Bulletin Podcast to talk about COVID-19’s potential to persist on surfaces, ways to mitigate the risk and testing that could help officials monitor the level of infection in communities (9:22 to 27:47). 


COVID-19 is transmitted through droplets from a cough or sneeze. These droplets contain the COVID-19 virus particles and can land on surfaces or the hand. People can get infected by first touching these surfaces and then their face, allowing the virus to enter their respiratory system.

There is little data on how people get infected from the environment after the infected person has left. But it is known that people do get infected when in close contact with other people. Scientists have shown that viable fragments of the virus can be collected from surfaces and be grown in a petri dish in the lab. The virus can last for three days on hard surfaces but it's viability exponentially decreases over time.

Mitigate the risk

The virus doesn't move on its own and needs a cell to replicate - only the area where the droplet falls contains the virus. The parts of a room or building that we need to be concerned about is the high touched surfaces, such as doorknobs and door handles. These types of surfaces have a higher likelihood of having COVID-19 particles. Diluted bleach or household cleaners are sufficient to remove the virus. Washing your hands is another important method to lower your risk of catching COVID-19.


One method could be tracking the virus through wastewater using it's genetic material. If high levels of the virus are detected in the wastewater of a specific pumping station it would provide valuable information about the population in that area, neighbourhood or building. In the future, this tracking method could serve as an early warning system by indicating whether the virus is present or has returned to a community. A second method to determine prevalence in the community is to identify the strain of the virus found on surfaces as this strain usually doesn't present symptoms in individuals, unlike the strains found in those showing symptoms. Finally, a commercial test that can demonstrate a facility is virus-free of COVID-19 would demonstrate cleaning practices are working and reassure the public.

Beyond the Bulletin is a weekly podcast with hosts Brandon Sweet and Pamela Smyth that highlights news, events and commentary from the Daily Bulletin, the University of Waterloo’s internal newsletter. The podcast also features a brief look ahead as well as an interview on a subject of interest to the University community.

Listen to Episode 45 (9:22 to 27:47) for the full interview.