Eight new cases of U.K. variant emerge in Ontario, including three in York Region without a travel connection, amid fears many more may be undetected

Thestar.com
Jan. 13, 2021

As Ontario announced it found eight more cases of the new, more contagious coronavirus mutation Tuesday, including three in York with no travel connection, concerns mounted that more cases of the variant could go undetected.

And with new modelling showing the U.K. variant could spread like wildfire within the province, the need to find which positive COVID-19 cases contain the mutation has never been more urgent, infectious disease experts told the Star.

Modelling by Troy Day, a mathematician and member of the Ontario Modelling Consensus Table, was addressed Tuesday by the province and shows that the U.K. variant, dubbed B1.1.7, could cause COVID-19 cases to double within 10 to 15 days. Currently, the strain of COVID-19 in Canada doubles within about 40 days, said Day.

“So you could imagine how that would get significantly worse if cases started doubling every two weeks,” he said.

There are fears cases could surge even further if the variant starts to spread, as the province’s Science Advisory Table announced Tuesday that about 40 per cent of long-term-care homes have active outbreaks. Provincial data Tuesday morning said 15 more LTC residents have died compared to the previous day, for a total of 2,995 since the pandemic began.

Admissions of COVID-19 patients to Ontario hospitals have increased by about 72 per cent in the last month, they added. And that’s without the U.K. variant yet moving significantly through the population, as far as officials know.

There have been 14 cases of the new variant detected in the province so far. Patrick Casey, director of corporate communications at York Region Public Health, said in an email that two people in the town of Georgina and one from Richmond Hill are the confirmed cases of the new U.K. variant with no connection to travel. That brings the region’s total of cases of the variant to seven, including four individuals in King Township who did have a travel connection. Of the seven, one case in York had been previously reported.

Peel Region has had two cases of the new U.K. variant, and both people “had close contact with a traveller from Dubai,” Peel Public Health spokesperson Ashleigh Hawkins confirmed in an email. One case in Peel had been previously reported.

Day based his modelling on the variant from how it is spreading within the U.K. He said he was initially surprised to see how quickly it could spread through the Ontario population, if the variant becomes the dominant strain.

But Day says his projections are a worst-case-scenario -- more precise modelling about the U.K. variant will rely on knowing if and where it’s spreading in Ontario.

Ontario’s associate chief medical officer of health, Dr. Barbara Yaffe, said at a press conference where the new modelling was presented that “it’s very likely” there are more cases out there. She added it seems to be “at least 56 per cent more transmissible.” It has mutations on the spike protein of the SARS-COV-2 virus that make it easier to catch.

There’s currently no evidence the variant causes more illness or death, or that the vaccines wouldn’t work against it. In Britain and Ireland, cases have exploded as the variant spreads.

Local health units are still interviewing the eight people but if no travel connection is found for the three that so far don’t have one, “then we have evidence of community transmission, and that is a very serious concern that the vaccine will not be able to address quickly enough,” Yaffe said.

Currently, Public Health Ontario (PHO) and its lab network are testing 500 to 600 samples a week to search for the U.K. variant, a spokesperson said in an email. Other labs in the province may be testing samples as well for the variant, they added. With the PHO’s testing alone, it is only assessing about 2.5 per cent of the more than 24,000 COVID-19 cases that were confirmed in Ontario over the last seven days for the variant.

The province tests the samples through genome sequencing and TaqPath PCR tests. By chance, the TaqPath PCR tests are able to detect the U.K. variant. PHO has also developed a screening test that is able to pick up a “signal for the U.K. and South African variant as well,” they said.

To determine which samples to test for the U.K. variant, PHO focuses on positive COVID-19 tests from those with a history of international travel or who have had contact with someone who travelled internationally, or positive cases that stem from a superspreading event, they said.

They are also engaging in a genomic surveillance program that monitors for variant strains and looks for patterns in communities that are “consistent” with the U.K. variant. Additional samples are sent, even if they do not meet criteria, they said.

Given the “rapid growth of cases in certain areas of Ontario,” PHO is also “actively conducting surveillance of positive samples from health units in Toronto, Peel, York, Windsor-Essex, Durham and Hamilton, and other health units with rapid growth rates as they emerge in collaboration with the Science Advisory Table.”

Genome sequencing to look for the U.K. variant and other variants is complex, and Canada has sequenced about five per cent of its total case count since the pandemic began, said Dr. Catalina Lopez-Correa, executive director the Canadian COVID Genomics Network (CanCOGeN), who is based in Vancouver.

CanCOGeN is a program under Genome Canada that includes federal, provincial and municipal health authorities to engage in genome sequencing to help governments make decisions around public health.

Nationwide about 1,100 samples a week of COVID-19 cases are sequenced and all are checked for the U.K. variant along with other possible mutations, said Lopez-Correa.