COVID-19 variants in Ontario: Study reveals how many patients are carrying UK, South Africa mutation

Public Health Ontario’s provided interim results from a point prevalence study, which identifies variants in positive COVID-19 test samples.

Dr. Vanessa Allen, the chief of medical microbiology at the Public Health Ontario Laboratory, explained that all positive COVID-19 samples from Jan. 20 were screened for the N501Y mutation in the spike protein, which is characteristic of the B117 COVID-19 variant, first identified in the U.K., the B1351 variant, first detected in South Africa and the P1 variant, first identified in Brazil.

Of the more than 3,000 samples from Jan. 20, 1,880 were screened and 5.5 per cent were positive for the N501Y mutation. Dr. Allen said that the majority were from the outbreak at the Roberta Place long-term care home in Barrie, Ont. A total of 1.2 per cent of the remaining samples, not associated with the outbreak, were positive for the mutation.

Five out of Toronto’s 301 samples were positive for N501Y and six out of Peel Region’s 403 samples were positive for the mutation.

“While this data may suggest lower prevalence, it does highlight the unfortunate circumstance of the outbreak and how quickly this variant spread,” Dr. Allen said, adding that the doubling rate is quite high at approximately one to two weeks.

There are currently 153 confirmed variant cases in Ontario, 152 B117 variant cases and one case of the B1351 variant.

Dr. David Williams, Ontario’s chief medical officer of health, did not provide any concrete information on whey the province could see public health measures loosened, but he stressed that with more schools resuming in-person instruction on Feb. 8 and then Feb. 16, the amount of community transmission is important.

He added that, particularly with the circulation of more transmissible COVID-19 variants, Ontarians have to ensure that they are following the public health rules in place.

“Do it well, do it better, do it consistently,” Dr. Williams said. “We have to stay the course.”

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