TORONTO — A snapshot of COVID-19 variants on a single day in January suggests levels of the more contagious strains in Ontario are low but that's expected to change quickly, public health officials said Thursday.
A Public Health Ontario study of COVID-19 cases on a single day in January found variants in 5.5 per cent of cases screened, with the majority linked to a long-term care home outbreak.
Dr. Vanessa Allen, the agency's top microbiologist, said the results highlight how quickly variants of COVID-19 can spread in an outbreak.
While the data suggests low prevalence, variants are expected to spread rapidly, she said.
"Essentially, doubling is expected approximately every one to two weeks," Allen said.
Public Health Ontario started screening all positive COVID-19 samples for variants on Wednesday, Allen said.
"Data in the coming days will be helpful to understand how this is evolving in the Ontario context," she said.
So far, Ontario has recorded 152 cases of the variant that first emerged in the U.K. and one case of another that first emerged in South Africa.
A third variant that first emerged in Brazil has not yet been detected in Ontario.
The variants are believed to be more infectious and health officials have said they might also cause more severe illness.
The province's medical officer of health, Dr. David Williams, said residents must continue following public health practices like masking and physical distancing to guard against further spread of variants.
"What we said before was important for COVID-19 writ large, now for the variant is even more important -- to be vigilant in what you're doing, be careful and cautious," Williams said.
In its study, Public Health Ontario screened 1,880 positive COVID-19 samples from Jan. 20 and found variants in 103 cases.
The agency said 89 of those cases were in the Simcoe-Muskoka health unit, where a deadly outbreak at the Roberta Place nursing home in Barrie, Ont., was linked to the variant.
Sixty-six residents at Roberta Place had died from the virus as of Thursday. The outbreak has infected more than 200 people, including staff and close contacts.
Outside of outbreaks, the Public Health Ontario study found 1.2 per cent of the total samples were variant cases.
More results from the study are expected in the coming days, the agency said.
The variant that emerged in the U.K. was first detected in Ontario in December and has since been found in 11 public health units.
In Simcoe-Muskoka, the local health unit reported that 91 cases of the U.K. variant had been confirmed in the region as of Thursday, with 60 other likely cases that were awaiting test results.
The unit also reported 85 deaths from COVID-19 in the month of January, "over four times higher" than deaths reported in December 2020.
Ontario reported 1,563 new cases of COVID-19 and 88 more deaths linked to the virus on Thursday.
Public health officials have noted, however, that updates to a provincial database are causing data fluctuations in this week's case counts.
- With files from Shawn Jeffords.
This report by The Canadian Press was first published Feb. 4, 2021.
Holly McKenzie-Sutter, The Canadian Press
