New COVID-19 modelling predicts up to 3,883 deaths by May 5

Canada could see up to 66,835 COVID-19 cases and 3,883 deaths caused by the pandemic by May 5, according to the latest modelling released by federal public health officials.

Speaking at a press conference in Ottawa today, Canada’s Chief Public Health Officer, Theresa Tam, said the new modeling data shows that caseload growth is slowing across the country and Canada has experienced slower growth than many other countries.

New modelling shows that while the number of new cases was doubling every three days when the first model projections were released on Apr. 9, it is now doubling every 16 days, Tam said.

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Short-term projections show that Canada is on track to hit between 53,196 cases and 66,835 cases and between 3,277 and 3,883 deaths by May 5, Tam said.

The COVID-19 fatality rate, which was initially calculated as roughly 2.2 per cent, has been revised to 5.5 per cent in light of a spike in deaths in long-term care homes, Tam said.

‘A tragic paradox’

Outbreaks in long-term care and seniors’ homes are driving recent epidemic growth in Quebec, Ontario and Nova Scotia currently, she said.

Nearly eight-in-ten deaths are occurring in long-term care facilities and seniors’ homes, a much higher toll than public health officials had initially used in their projections, forcing them to adjust their models to account for the phenomenon, Tam said.

“Right now we are seeing the tragic paradox of the epidemic playing out,” Tam said. “As the epidemic comes under control and the growth of cases slows, the severe outcomes and deaths continue to accrue as COVID-19 takes a heavy toll among highly susceptible populations.”

Significant regional differences

There are also significant regional differences.

The infection rate in Quebec, Ontario and Alberta is driving the epidemic’s growth in Canada, while the number of cases has levelled off in several provinces, Tam said. There are no cases in the Arctic territory of Nunavut and no community spread in Prince Edward Island, Northwest Territories or Yukon.

As of Tuesday morning Canada had registered 49,025 cases of COVID-19 and 2,766 deaths, she said. Nearly 740,000 people have been tested so far with about seven per cent of them testing positive for the virus, Tam said. About 20,000 people across Canada are tested daily, she added.

Officials laid out three different potential scenarios – green, blue and red – based on strong controls (one-10 per cent of the population infected), weaker controls (25-50 per cent infected) and no controls (70-80 per cent infected).

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Canadian public health officials are working to implement the “best case” scenario where each infected person in turn infects fewer than one other person, Tam said.

To stay on this “green” best case scenario curve, Canada must achieve and maintain a high degree of physical distancing while also maintaining a high rate of case detection and isolation, and contact tracing and quarantine, Tam said.

“By achieving epidemic control, we expect that only a small proportion of the population will be immune, so until the population has developed a high level of immunity to the virus or we have a vaccine in place, we have to plan to live with a manageable level of COVID-19 activity,” Tam said.

“Therefore we anticipate that some public health measures will need to remain in place to prevent the sparking and growth of future epidemic waves.”

‘Living with the virus for a significant number of months’

Canada is making “clear progress” to slow the spread and bring the epidemic under control, she said.

Because the situation with COVID-19 differs widely across Canada, lifting of some of the restrictions will depend on the local epidemiological situations, she said.

“It is critically important that we maintain our public health measures, including physical distancing until we have achieved epidemic control for the first wave,” Tam said. “Relaxing controls too quickly will squander our collective efforts to date and put us at risk of a future epidemic wave.”

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Because a significant proportion of the population is not immune and significant questions remain about the immunology of this particular virus, “we will not go back to what life was like before January of this year,” Tam said.

“Public health authorities will be easing things very gradually but we talk about living with the virus for a significant number of months and until there is enough level of immunity,” Tam said.

‘A very delicate balance’

But these measures are buying us time to not only work on a vaccine but also develop treatments to manage some of the more serious outcomes of the illness, she said.

The easing off some of these public health measures would be done in certain settings where officials can manage physical distancing and manage protocols at workplaces to reduce transmission, Tam said.

“I would love to be able to tell Canadians that life would be back exactly to where we were in December of last year but no, we’re going to be having different daily routines,” Tam said.

However, this has to be balanced with all the other unintended consequences of lockdowns, Tam said.

“We know the impacts to mental health, to gender-based violence to other aspects of society and the economy,” Tam said. “It is a very delicate balance that we all have to manage really well.”

COVID-19 in Canada: Modelli… by Levon Sevunts on Scribd