Unprecedented levels of COVID-19 across Canada are driving hospitalizations as well and once again threatening many provincial health-care systems.
Yet experts say it’s too soon to say how much hospitalizations could grow in the days and weeks to come. With testing capacity at its breaking point and data still coming in on Omicron’s severity, they say modelling this latest wave will require updating their methodology.
“We’re flying blind,” said Caroline Colijn, a mathematics professor at Simon Fraser University who has been modelling the pandemic in British Columbia.
“There’s a good chance that by the time we have a clearer picture of where we are and where we might be going, we could be in the middle of a major situation for the health-care system.”
Hospitalizations have always been a lagging indicator in the pandemic, with a rise in patient intakes usually coming weeks after cases start to climb.
This latest, Omicron-fuelled wave has been no different. While cases began to notably increase at the beginning of December, the number of cases in hospital began trending upward two weeks later.
There are now over 2,700 patients in hospital with COVID-19, including nearly 500 in intensive care, a level last seen this past October.
The surge has largely been driven by Ontario and Quebec, where case counts have surpassed 10,000 per day. In Quebec alone, hospitalizations have doubled in just one week, with 939 patients receiving care as of Thursday.
But the sudden spike in lab-confirmed infections — including a staggering 39,700 on Thursday — has created a perfect storm of unpredictability about what happens next.
Because Omicron has proven to be much more transmissible, testing capacity has been pushed to the limit, with health officials warning official case counts are likely an undercount. And with at-home rapid tests becoming more prevalent, not all positive results from those test kits are being reported to public health, creating gaps in the data.
Meanwhile, research is suggesting Omicron may not lead to as many hospitalizations as the more severe Delta variant. A Public Health Ontario study released Thursday found that on average, the risk of hospitalization or death was 54 per cent lower in Omicron cases than Delta cases.
The problem, as Colijn points out, is that less chance of hospitalizations may not be good news if cases are exploding at the current rate.
“Even with a lower rate of hospitalization, if you have 20,000, 30,000 cases a day or more, that’s still potentially sending a lot of people to the hospital,” she said.
Omicron cases surge across Canada
Modelling that has been released so far does not bode well for the rest of the country. The research institute that reports to the Quebec government said Thursday its modelling predicts “significant growth in new hospitalizations and the consequent occupancy of regular and intensive care beds over the next three weeks.”
The Institut national d’excellence en sante et en services sociaux said its models show there could be between 1,600 and 2,100 COVID-19 patients outside intensive care units over the next three weeks. It said there could also be between 300 and 375 ICU patients during that period.
The most dire scenarios — 2,100 regular COVID-19 patients and 375 ICU patients — would surpass anything recorded during previous waves of the pandemic.
Provinces have also begun to report higher numbers of health-care workers testing positive for COVID-19, forcing them into isolation and out of the hospitals where they’re needed.
At least one hospital in Ontario, Queensway Carleton in Ottawa, said Wednesday it would slow down some services after 40 staff tested positive for COVID-19.
Quebec and Ontario this week shortened the isolation period for those workers from 10 days to seven in order to prevent staffing shortages. Manitoba and British Columbia have said they’re considering similar moves, while Alberta announced it would allow unvaccinated health workers back on the job, provided they undergo rigorous testing.
Daniel Coombs, an epidemiology modelling expert at the University of British Columbia, points out that even as Omicron pushes infections skyward, the Delta variant remains prevalent across the country and is still responsible for many of the current hospitalizations.
He said his team and other modellers will be looking to other countries where testing capacity isn’t being so strained, like Denmark and the United Kingdom, to try and get a sense of where Canada could be headed. Wastewater testing will also play a role.
Those factors will have to stand in for the testing gaps that Coombs said allowed epidemiologists to understand the impact of Delta more quickly than that of Omicron.
“When the Delta wave came in, we still had really great testing,” he said. “So we sort of understood, ‘OK, we’ve just got to recalibrate.’ And now … it’s not just a recalibration, we’re going to have to come up with new ways of understanding what’s going on.”
Unprecedented COVID-19 case numbers could change protocols
Not all provinces are seeing increases in hospitalizations. In Saskatchewan, the number of patients has trended downward by about 20 per cent compared to two weeks ago, while ICU levels have flattened in Alberta and B.C.
Saskatchewan Premier Scott Moe has pointed to the decreased hospitalizations as proof that more restrictions aren’t needed, focusing instead on boosters.
Yet he echoed health officials in other provinces who said this week that hospitalizations will be the new metric that will determine their public health responses, as case counts become less precise.
Quebec on Thursday responded to its increased patient intakes by reintroducing a nighttime curfew not seen since last winter.
In a statement Thursday, Canada’s chief public health officer Dr. Theresa Tam urged Canadians to get vaccinated if they have not already done so, and for eligible adults to get a third booster dose as soon as they are eligible to help control the spread.
“Keeping infection rates down remains key to avoiding renewed increases in severe illness trends over the coming weeks and months, as well as to ease the longer-term strain on the health system, particularly in heavily impacted areas,” she said.
–With files from the Canadian Press
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