Roger De Melo reported COVID-19 symptoms on Friday, but the quick test came back negative.
"I thought it could be COVID, but the fact that I was getting negatives - I'm doing OK," De Melo told CTV News, adding that he tested again the next day.
"By Saturday, I had developed a cough, and I figured, no, that's surely COVID."
On Sunday, he took a third test, which came back positive.
According to Julie Lajoie, an immunology professor at the University of Manitoba, the first fast test may not be positive.
"The trouble with Omicron now is that people will be sick for one or two days, they will test negative, and they will assume, 'OK - it's another virus because there are a lot of other viruses in the air now," Lajoie explained to CTV News. "But now we need to test a little more frequently."
"The difficulty with quick tests is that they are very different from the gold standard PCR that goes to the lab," said Cynthia Carr,
Carr stated that the strain determines how well fast testing detect COVID-19.
"With Omicron, the average is around 40%." "Four out of ten tests correctly identify that person as having the virus," she said. "So it should not be the sole tool used, and you should definitely do it more than once."
Another issue with the strains, according to Carr, is how effective immunizations are and whether therapies would work on it.
According to Lajoie, Omicron is more prevalent in the upper respiratory tract than prior strains. When testing, she recommends swabbing the neck, cheeks, and nose.
"Rapid tests are extremely important tools; we just need to tweak how we utilize them with Omicron," Lajoie explained.
Lajoie advised testing for COVID-19 every 24 hours for three days to ensure you are not positive.
