According to Montreal-based economist Joshua Lewis, the number of confirmed COVID-19 cases is just "the tip of the iceberg." Lewis, an assistant economics professor at Université de Montréal (UdeM) is the co-author of a study that revealed there could be 12-times more cases than what's actually being reported. Lewis's study indicated that as of April 22, 2020, Quebec's "actual infection number" was at 256,130 people.
The UdeM study was informed by a similar study conducted in the United States also co-authored by Lewis.
"The big motivator for the research, in general, was this question of how to figure out the overall prevalence of coronavirus across locations, and particularly when we know that different states, different provinces, are testing at very different rates," he told MTL Blog.
The study evaluated the numbers from Quebec and Ontario with striking results.
Despite the differences in the provinces' official reports, the actual number of cases is "remarkably similar," Lewis wrote.
On May 1, Quebec Public Health Director Dr. Horacio Arruda acknowledged the accuracy of these studies, saying that as much as 3% of the population may have been infected.
While there are many uncertainties regarding the prevalence of COVID-19, Lewis admitted, knowing how many actual cases there are could help governments make better public health decisions.
"Governments may greatly understate the true scope of infection since large numbers of individuals with mild or no symptoms go untested," the study's authors explained.
Though Lewis was hesitant to comment on the specific policies of Quebec's public health authorities, he noted that it would benefit the government to utilize the study's methodologies to get a clearer picture of what's actually going on.
"What I think will be useful going forward, especially because this is the end of the beginning of this pandemic — because it's nowhere near its end — is to aggressively expand testing, which both provinces are doing. But I think it also may be beneficial to adopt some population-based random testing."
"These studies are finding that the people that actually test positive is just a small portion and a big explanation for that is that people who have no symptoms never bother to show up to be tested," said Lewis.
In addition to better tracking the virus, expanded testing efforts could provide insight into the number of people who have developed antibodies.
"The advantage with that is once people are identified as having antibodies, they may be more likely to be able to return to work safely."
Quebec's public health officials are proceeding with a gradual reopening of the province and deconfinement of the population.
Additional testing is already underway in some of Montreal's hardest-hit areas.
But challenges remain.
"Aggressive reopening... there's a risk of that leading to a reemergence of disease, but of course, we can't stay closed indefinitely," said Lewis.
"I think there's so much uncertainty. I think it's difficult to say what the optimal policy is in terms of the timing and how quickly to reopen, but I think there are costs. With every decision, there are trade-offs that have to be made."
Stay tuned for more news.