Canada’s Public Health Agency has warned of a potential fall peak in COVID-19 cases that could reach higher numbers of new infections than ever before and overwhelm the health care system.
In a news conference on Friday, Chief Public Health Officer Theresa Tam presented new projections of infection rates in which the “reasonable, worst-case scenario” showed a large peak in the fall and “peaks and valleys” continuing into 2022 that would at times exceed the public-health system’s capacity to manage.
Dr. Tam also presented an alternative scenario she described as a “slow burn,” with continuous low rates of infection into 2022 that hospitals and health-care centres could manage. She said it is too early to predict which path Canada is on.
“The take-home message is that the fate is still within our hands, and what we do now will influence the probability for that fall peak,” Dr. Tam said.
Short-term modelling projections based on current case numbers indicate that by Aug. 23, the number of cases could be as high as 127,740, up from the current total of 121,650. Deaths are predicted to be as high as 9,115.
Dr. Tam said that as restrictions are lifted, she expects a resurgence in cases until treatments or vaccines become available, but that the goal will be to keep rates low and manageable.
She stressed that while some restrictions are loosened, others need to be tightened to prevent increases in infections. The rapid detection and isolation of cases, and adherence to physical distancing and protective measures among the public are the most important factors in limiting the spread, she said.
“Lifting restrictive public-health measures like school and business closures without strengthening these other controls will likely cause the epidemic to rebound.”
Dr. Tam also said the fall flu season is expected to occur along with the pandemic, and health officials plan to manage a potential “convergence” of viral activity.
The data released by the federal public health agency also showed a high rate of cases in young adults aged 20-39 since mid-July, supporting previous data from provincial agencies that indicate many outbreaks were linked to indoor gatherings of young people who did not practise adequate physical distancing.
On Friday, Toronto Public Health warned that up to 550 people could have come into contact with the virus at the Brass Rail strip club, which had an employee who tested positive the previous weekend.
However, the federal data also showed that the highest number of outbreaks continues to be linked to long-term care homes and seniors’ residences, followed by restaurants, bars and retail establishments.
Some experts warn that if cases surge, more restrictions and more closings of businesses, schools and community spaces could be required.
Isaac Bogoch, an infectious diseases physician at Toronto General Hospital, said regional public health units should “absolutely” consider reimposing restrictions if numbers climb.
“If there’s an unacceptable number of new cases, the public health units could certainly clamp back down,” he said.
Dr. Bogoch said restrictions would likely be decided at the regional or provincial level, based on local numbers and projections. Factors that could influence the decision might include challenges with tracing people’s contacts quickly, evidence of widespread community transmission, or a high percentage of tests coming back positive in a region.
But he added that many of the countries that have been most successful at keeping cases low have tightened restrictions after an initial phase of reopening.
“Every country that Canada points to that has been successful managing this – Japan, Germany, Australia, South Korea – all of these countries have had a rise in cases after they got their epidemic under control, and all of these countries reimposed many public-health restrictions to some extent to get their infection under control,” Dr. Bogoch said.
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