What to know about COVID testing amid BTNX rapid test controversy

With holiday gatherings around the corner, Canadians may have questions about how to properly test for the virus at home. Here's what you need to know.

With holiday gatherings around the corner and a growing controversy over the importer of millions of COVID-19 rapid tests, Canadians may have questions about how to properly test for the virus at home.

A Global News investigation found the Toronto-area rapid test importer BTNX landed an estimated $2 billion in federal contracts in 2021 and 2022, despite evidence the company gave regulators incomplete data about its product’s accuracy. BTNX has denied the data was incomplete and says it provided regulators with accurate information.

The rapid test is among the more than 30 models of at-home COVID-19 testing devices that have been approved for use by Health Canada to date, and some testing kits remain available free of charge at local pharmacies across the country.

Most of those tests — including all of the latest ones approved for distribution — have between a 90 and 100 per cent sensitivity rating, according to Health Canada approvals, which are a measure of their effectiveness and accuracy.

“As the (regulatory) process was improved there were certainly some improvements (to the tests) since the beginning of the pandemic,” said Dr. David Juncker, a professor and chair of the biomedical engineering department at McGill University.

However, provinces and territories say tests should only be taken when experiencing the symptoms of respiratory disease, or if there has been a known exposure to COVID-19.

In the latter case, the U.S. Centers for Disease Control and Prevention recommend waiting at least five days after exposure before testing.

That’s because it can take three to seven days after infection for there to be enough antigens to be detected by a rapid test, according to the British Columbia Centre for Disease Control. Testing too quickly can result in a false negative.