Canadian labs have detected about two dozen cases of concerning COVID-19 variants in our country so far.
A highly contagious strain first detected in the U.K., South Africa or Brazil is suspected in a recent outbreak at a Barrie, Ont. nursing home. Canada’s Chief Public Health Officer has said community spread may already be happening.
But while Iceland, Australia and New Zealand test nearly all their COVID-positive cases for variants, Canada screens just five per cent.
The executive director of the Canadian COVID-19 Genomics Network (CanCOGeN) knows that number seems low, but she points out Canada has a lot more cases than many countries. Dr. Catalina Lopez-Correa says a better comparison is U.K. screening rates.
“The U.K. is doing about six or seven per cent, and other countries like the U.S. are doing less than one per cent,” Lopez-Correa told Global News.
“For us, because we have a large number of cases in Canada… five per cent is already very good coverage.”
Canada has tested more than 30,000 positive samples for variants so far. That involves genome sequencing — an expensive, complex process that takes days.
“Variant level work, by design of the technology, is much more expensive, so we can’t do them all,” Dr. Andrew McArthur said.
He’s an associate professor of Biochemistry at McMaster University.
McArthur’s lab helps screen for variants in Ontario. He explains there are ways to speed up the process.
The U.K. variant, for example, can be detected by looking for specific mutations of the virus. That result still needs to be confirmed by sequencing the whole genome.
“Do you find all (cases of variants)? No. But you do a surveillance effort to indicate whether they’re in the community or whether they’re travel-related,” said McArthur.
Canadian labs also target specific groups: international travellers, cases related to outbreaks, people who have been re-infected with COVID-19 (those will be of special interest if they’ve been vaccinated), and cases that just don’t make sense.
“We are looking for (people) younger than 50, or younger people that are otherwise healthy, and for some reason develop a very severe disease,” said Lopez-Correa.
Alberta Precision Laboratories has detected more than half of all of Canada’s variant cases; 12 of the U.K. strain, three of the South African in about 4,000 Alberta samples tested.
“Are we finding the U.K. variant in returning travellers from the U.K. and Europe? Yes we are. Is that unexpected? No, it’s not unexpected at all,” said Medical-Scientific Director Dr. Graham Tipples.
Tipples says the more screening, the better, but his lab is “going full speed.” Even with more funding and equipment, ramping up testing wouldn’t be easy.
“Certain staff that are doing diagnostic tests have to have certain training credentials… and they’re all hired. There are no more to hire.”
The Alberta Health Services-owned lab is developing rapid tests for select variants. But until testing can ramp up, there is no way to know for certain which strains are in the community.
McArthur points out the novel coronavirus doesn’t need travellers to mutate. The more it spreads, the more it can evolve.
“It’s a numbers game… The more time that goes by and the more people that are infected, the more likely new variants will come.
“You can look at Quebec and Ontario,” McArthur said. “It’s been a concern that we will generate our own variant.”
Approved COVID-19 vaccines do protect against current variants, but it may not be long before one mutates enough to escape that immune response.
“We are in a bit of a knife fight between how many community cases we get and how quickly we can vaccinate,” said McArthur.
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