TORONTO -- As millions of Canadians spend their days at home, avoiding getting too close to anyone outside their households, one question rises above all: When will this be over?

Ashleigh Tuite is about as well-positioned as anyone to know the answer to that question. She's an expert in developing mathematical models to forecast the spread of infectious diseases. Not only that, she's part of a team at the University of Toronto that has been given federal money to specifically model the COVID-19 pandemic.

But when it comes to what may happen next in Canada, Tuite has no special insight.

"'I don't know' is the honest answer," she told Thursday via telephone.

"It's a little bit too early, at least here and with the data we have, to be able to do the forecasting work that I think there's a huge appetite for."

Even knowing exactly how far Canada is into its COVID-19 outbreak is difficult. The number of cases in Canada rose by 42 per cent on Monday, 34 per cent on Tuesday and 22 per cent on Wednesday -- but there are so many factors at play that it is impossible to reach any useful conclusions on whether the country is flattening its curve.

Testing activity is ramping up, but not at the same rate in every province, and not every part of the country is prioritizing the same cases for testing. There's also inequity in processing backlogs -- and that there are backlogs at all means today's new cases involve people who first contracted the virus several days ago.

It takes even longer for the effects of closures, movement restrictions and other government actions to show up in the data. Because it is generally believed that the virus has an incubation period of up to two weeks, experts say it is only safe to assume that one day's case number represents the results of actions taken 14 or more days earlier.

All of that results in a constant game of catch-up for doctors looking to treat patients, health authorities looking to implement the necessary measures to keep COVID-19 patients from flooding into hospital beds, and anyone looking to simply keep up with what's happening.

"We don't exactly know where we are on the epidemic curve, and we don't exactly know where we were when we started having our strong public health response," Tuite said.

To try to close that gap, some researchers look at the progression of the virus in other countries and try to adjust those experiences for the Canadian context. One team from York University in Toronto attempted to project the spread of COVID-19 in Canada based on the example of Italy, where more than 8,000 deaths have been recorded.


Italy is currently one of the world's grimmest examples of the toll COVID-19 can take. Nearly one in 10 of Italy's 80,000 known cases are health workers, and it is believed the real number of the infected is significantly higher, as the country has prioritized testing only those most likely to have the virus.

The York researchers found that Canada's COVID-19 curve up to March 22 appeared similar to Italy's about three weeks earlier. At that point, Italy was starting a mass quarantine of part of the country, while life still continued relatively normally in other regions for a few days. The full lockdown of the country was still a week away.

Because Canada had already cracked down on public gatherings before March 22, the researchers concluded that "Canada will not become the 'next Italy,'" but warned of a worst-case scenario in which there would be 15,000 confirmed cases of COVID-19 in Canada by March 31.

Even that scenario no longer appears to be a significant risk, postdoctoral fellow Dr. Nicola Luigi Bragazzi told on Thursday, because of the stricter measures Canada has taken since March 22, including requiring anyone entering the country to quarantine for 14 days.

"These measures are extremely useful and helpful," he said via telephone.

Other scenarios modelled by the York team, involving various forms of government action, project caseloads far below 15,000 by March 31.

But when it comes to one of the country's main goals right now -- keeping the outbreak from overwhelming the health-care system -- does the total number of cases even matter?

Tuite doesn't think so. She says the number of deaths is a better indicator, albeit one with its own problems. COVID-19 deaths typically occur three to four weeks after infection, meaning projections based on deaths have a lag time even longer than what it takes for movement restrictions to be reflected in the data.

What she and many other researchers would like to see is data from each province on COVID-19-related hospitalizations -- something most provinces are not yet routinely including in their updates. That would allow for a greater focus on only the most severe cases of the disease, while also making it easier to forecast how demand for hospital beds will change over time.

"If we're able to monitor that, that will give us a very good sense of where we are in the epidemic," Tuite said.


The models, projections and experts may have a hard time saying exactly what will happen with any confidence, but they all agree on one thing: the numbers will continue to rise for weeks.

Consistent large increases would be an obvious problem, because the health system would not be able to manage them for long. Consistent small increases could present a challenge of their own, as Canadians may take them as a sign that the measures enacted by the government were an overreaction.

This is another reason why Tuite wants to see more detailed communication from governments about how cases are being managed -- because that information can then be used to help inform the public about the reality of the situation.

"If you're asking people to buy into this, I think there needs to be a way to communicate that what we're doing is having an impact," she said.

Tuite pointed to the sudden escalation of the COVID-19 situation in New York City as an example of what can happen when public buy-in comes too late, suggesting that Canada could be in "a very different place" had government action and recommendations for physical distancing come a week or two later.

Bragazzi, too, cautioned that Canadians should not get complacent, noting that the effects of actions taken today will not be reflected in statistics for weeks. He suggested that Canada look to China, South Korea and Italy as examples of three approaches to fighting the virus with different outcomes.

"The critical time to act is now. Canada can benefit from and capitalize on the lessons of other countries," he said.

There are signs that the government is trying to prepare Canadians for a longer life under not-quite-lockdown than they may have expected when the measures were first announced.

Asked at a press conference Wednesday about how long it might take the country to start returning to normal, Dr. Howard Njoo, the country's deputy chief public health officer, responded that "if you look at the science and the evidence … it's not days and weeks, but certainly months that this pandemic will endure."