Study estimates Quebec actually had 58,000 new COVID-19 cases per day last week

How big has the Omicron wave been in Quebec? Much, much bigger than people think, according to a new study that estimated the full, uncounted number of infections in mid-January.

Quebecers have already known for a few weeks that the official case numbers released each day did not reflect the true spread of the virus, since most people have been unable to get a test.

The province maxed out its testing capacity before Christmas and then officially limited tests to only a few groups, including health-care workers and teachers. At the same time, even at-home rapid tests were nearly impossible to get.

In the week the researchers studied, Jan. 13 to 18, official case counts hovered roughly between 4,000 and 6,000 new cases each day.

In reality, there were probably "an average of 35,000 to 40,000 positive tests per day in Quebec during the period," the researchers found, if you include rapid tests.

And the full daily prevalence of new cases is even higher: they ended up estimating it at 58,144 on average, per day, in that week.

They used several methods to include not only the official PCR test results, but at-home rapid tests and people who had COVID-19 symptoms but didn't take any test, and who very likely had the virus.

The rapid tests alone, not taking into account the untested cases, caused the scientists' estimates to balloon five-fold.

"Regardless of the method and estimator used (excluding self-diagnosis), we obtain an incidence that is about five times higher than the official figure," the researchers wrote.

If those numbers seem high, think again, said Dr. Christopher Labos, an epidemiologist at McGill University.

"I think it makes sense. I think it's very reasonable," he said after reviewing the study's estimates. Labos did not contribute to the research.

"I think most people realize that the number of cases being reported is an under-report," he said.

"There's a lot of people that are going undiagnosed because they're either diagnosing themselves with symptoms, or they're getting rapid tests, which are not reflected in the official numbers. So the daily case counts are certainly underestimates."

The government knows this as well, which is why "you've seen [it] sort of rely increasingly on the number of hospitalizations as an indication of how things are going," he explained.

Based on hospitalizations, it seems as if new cases are likely stabilizing, he said -- something authorities said they were starting to see over the last week.

"The inference [is] that because the new number of hospitalizations has been relatively stable recently... things have sort of started to level off here, and that we might be past the worst of the Omicron wave," he said.

However, Labos said it's important for the government to find a way to begin including positive rapid tests, at least, into its own official counts. They're reliable enough for that, he said.

"We have to also try to find some way to incorporate the rapid antigen tests into our testing numbers," he said.

"Those are valid tests. If you have classic COVID symptoms in a positive antigen test, I mean, it's a pretty fair assumption that you actually have COVID -- I think the test would be very reliable in that context."

The researchers behind Friday's study plan to repeat the survey over the next four weeks in a row to follow "the evolution" of the virus's curve, using their own metrics.

This is a developing story that will be updated.