As novel coronavirus continues to spread world wide, researchers have begun modelling how the pandemic could look in Canada over the long-term.
Researchers at the University of Toronto’s Dalla Lana school of public health modelled how the COVID-19 outbreak would look in Ontario with restrictive measures in place to flatten the curve, compared with what might happen without those measures.
Using the number of patients requiring treatment by intensive care units (ICU) as a metric, they forecast how the epidemic could look over a two-year time period.
The study found that with limited testing and restrictive measures, approximately 56 per cent of the province’s population would be infected over the course of the epidemic.
However, they said all interventions, including physical distancing and enhanced detection of cases, were projected to delay and reduce the height of the epidemic’s peak.
Restrictive social distancing was estimated to have the greatest effect.
“Without significant social distancing or a combination of moderate social distancing with enhanced case finding, we project that ICU resources would be overwhelmed,” the paper reads. “Dynamic social distancing could maintain health system capacity and also allow periodic psychological and economic respite for populations.”
When they modelled what the outbreak would look like with a combination of enhanced testing and social distancing, it appeared more as a wave like-pattern.
Ashleigh Tuite, an epidemiologist who was part of the research group, said the point of the study was to compare different scenarios to identify ways to limit the virus’ spread over the long-term that doesn’t “completely devastate the economy and our society.”
“The idea is really to get a sense of when we’re talking about different interventions: what time periods are we looking at? How does that change the shape of the curve?” she said. “And also to start thinking about how do we manage this, because we’re not talking about a couple of discomforts and then return back to normal life.”
Tuite said the modelling suggests we may be able to slowly relax some of the restrictive measures once we see the outbreak subsiding.
“But again, you have to continue to monitor what’s happening in terms of the outbreak and spread,” she said.
Tuite cautioned, though, that if restrictions are removed too quickly, we could see a “rapid resurgence of spread” of the virus.
The province is better equipped to deal with a series of smaller waves than one big wave, she said. “Basically, can react to that, and increase or decrease the level of intervention depending on what we see happening in the community and in terms of our hospitals.”
‘Best case scenario’
Tuite said the modelling was done over a two-year period because that is how long researchers anticipate it will take to develop a vaccine.
If a vaccine is available within that time, and Ontario is able to effectively limit the spread of the virus, Tuite said modelling suggests approximately five per cent of the population would be infected with COVID-19 over the course of the epidemic.
She said this is likely the best-case scenario.
“Assuming that we were not able to completely eliminate COVID from our population — which I think is a realistic assumption that we are going to be dealing with it for a while — that’s probably a best-case scenario where we’re really monitoring what’s happening and reacting quickly and basically able to quickly turn interventions on as we need them.“
However, Tuite said a number of factors could still change the shape of the model, including how large the initial spike in cases is, or if the pandemic subsides over the summer.
“But I think in general, the qualitative findings hold, which is that while you have these interventions in place, you are able to reduce spread,” she said. “And when you remove them, you can expect cases and transmission to start increasing.“
B.C. modelling shows drop in new cases
On Friday, health officials in B.C., released their own modelling, saying the province’s transmission rate had dropped from about 24 per cent to 12 per cent.
B.C.’s health officer, Dr. Bonnie Henry, said the results left her feeling “cautiously optimistic” about the future.
Researchers compared the growth rate of COVID-19 cases in B.C. to growth rates in China’s Hubei province, northern Italy and South Korea, and examined how B.C. hospitals would deal with those circumstances should they ever arise.
The data suggests B.C. is closer to a South Korea-type spread of the virus at present, and if the province was to continue to deal with that level of infection, its hospitals would have enough beds and ventilators.
Canada’s Chief public health officer cautioned that Canada is a “big country,” and that regions will experience differing periods of acceleration and deceleration.
What’s more, in an email to Global News, Dr. Suzanne Sicchia, an associate professor at the Interdisciplinary Centre for Health and Society at the University of Toronto Scarborough, said that the data from B.C. was “promising,” but that we should be “very cautious in making any definitive claims and even more so when it comes to generalizing these findings to other provinces.”
“Certainly, if the trend continues in B.C., we will know that we’ve been effective in flattening the curve in that province and that bodes well for us all.”
According to the Public Health Agency of Canada, as of Tuesday morning, more than 7,700 cases of COVID-19 had been confirmed in Canada.
So far the virus has claimed 89 lives across the country.
—With files from Global News’ Richard Zussman and The Canadian Press
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