Distancing, testing and tracing key to controlling COVID-19 this fall: University epidemiologist

Ashleigh Tuite, an assistant professor at U of T’s Dalla Lana School of Public Health, says it’s “extremely likely” we will see a resurgence of COVID-19 in Canada, but the timing and severity is difficult to predict (photo by Nick Iwanyshyn)

The novel coronavirus isn’t so novel anymore.

As the global COVID-19 outbreak reaches the half-year mark, more than 10 million people have been infected and more than half a million have died, including about 8,600 in Canada.

While the epidemic curve appears to be falling in Canada, infections are surging at an alarming rate in many other countries.

Earlier this year, Ashleigh Tuite, an epidemiologist and assistant professor at the University of Toronto’s Dalla Lana School of Public Health, created models of the outbreak with colleague Professor David Fisman. At the time, they predicted that social distancing would be required for months, not just weeks, to flatten the curve.

U of T News writer Geoffrey Vendeville recently checked in with Tuite to get her take on what we have learned about the disease over the past several months, what we still don’t know and whether we will face another wave in the near future.


In your view, how likely is it that we will experience another wave?

I think it’s extremely likely that we’ll see resurgences of COVID-19. A large proportion of the population remains susceptible to infection. Population immunity remains well below the levels needed for herd immunity, which would prevent subsequent waves of infection (assuming that immunity is long-lasting).

The timing of these resurgences and how big they’ll be is less predictable. It will depend on a number of factors including: seasonal effects; how well we continue to adhere to protective measures, including physical distancing and wearing masks indoors when distancing isn’t possible; and our public health testing and tracing strategy.

If we have a strong public health response focused on rapid testing, contact tracing and isolation of cases when case counts remain low, we should be able to control small flare ups and prevent large epidemic waves. If we don’t have those systems and processes in place, we’re going to be in for a much more difficult time.

The last time we spoke, you said it remained to be seen whether the changing of the seasons would affect the virus. Do we have a better idea now if the virus is seasonal?

The unsatisfying answer is we still don’t really have a good answer. It’s difficult to conclusively determine if there are seasonal patterns for a virus that has been circulating for less than a year in humans.

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