TORONTO — An infectious disease expert at the University of Toronto has asserted that about 30 percent of negative COVID-19 tests are false.
While social media’s armchair commentators tend to focus on alleged false positives yielded by the PCR test used in Ontario, the U of T’s Dr. Anna Banerji brought up precisely the opposite concern during a recent interview with provincial broadcaster TVO.
“Like, early in the pandemic, it was very clear to me that there are people that had false negative tests. These people who had classical symptoms of Covid, they had maybe a partner who is in the hospital with Covid. Clearly, there’s nothing else they could have had,” Banerji told host Nam Kiwanuka on the Nov. 30 edition of The Agenda with Steve Paikin.
“If you look in the literature,” Banerji continued, “about 30 percent of the people with Covid actually have a negative test, and they do have Covid.”
This false negative rate has implications for contact tracing and “basically trying to control the outbreak,” she observed. “If you’re only following the 70 percent of the people that have positive tests, then you’re missing the 30 percent.” Describing the Ford government as “deaf to a lot of issues,” the doctor said she has raised concerns with provincial and municipal officials as well as Canada’s Chief Medical Officer of Health Dr. Theresa Tam.
But what about false positives from Banerji’s point of view? Via Twitter, the doctor told NVN’s Nelson Zandbergen that false positives “are not very high at all.”
“I would have to look at the exact numbers. I think the denial that someone has Covid, especially if they have Covid and no symptoms, is much higher,” she wrote.
Below, Dr. Benerji addresses the issue of false negatives on TVO’s The Agenda with Steve Paikin (video is queued to start at the applicable section).