|CBC News has received countless audience questions about the pandemic, and is working to answer as many as possible.
As for the issue at hand: for the most part, no, increased case counts aren’t a result of more testing — but the amount of testing does make a difference. For Ontario, the new daily case records are partly because of the increase in testing, said Dr. Sumon Chakrabarti, an infectious disease specialist with Trillium Health Partners in Mississauga.
Ontario completed more than 48,000 tests on Oct. 7 (two days before setting a record of 949 cases in one day) — about quadruple the 12,000 it ran on April 24 when the province hit a spring peak of 640 cases. At that time, Chakrabarti estimates about three-quarters of cases were being missed, and there were likely closer to 2,500 cases a day in late April. However, the real number of cases in Canada is definitely higher than it’s been since the spring peak.
All things being equal, if you test more of the population, you will end up testing more people with COVID-19, which will cause the case counts to go up, but you will typically test even more people without COVID-19, causing the percentage of positive tests to decrease, said Cynthia Carr, founder of the Winnipeg-based epidemiology consulting firm EPI Research Inc. But in fact, the percentage of tests that come back positive is increasing in many places, including Manitoba. In that province, the real number of cases is “definitely an increase relative to the spring.”