MONTREAL — The number of daily, reported COVID-19 infections in Montreal remains at a high plateau, the city's public health director said Wednesday, and she warned that new cases of novel coronavirus variants may be circulating undetected.
Dr. Mylene Drouin told reporters that nine cases of new variants have been confirmed in the city, adding that 23 suspected cases remain unconfirmed. Another 12 cases, she said, are believed to be variants because they are linked to confirmed cases.
There are three variants that concern the city's public health authorities: the ones first detected in Brazil, South Africa and the United Kingdom.
"We know that those variants are more transmissible," Drouin said. "And for the U.K. variant, we also have data that shows us that it causes more severe forms of the illness." There are also fears, she added, that vaccines may be less effective against the other two variants of concern.
Most of the variants identified in Montreal are the U.K. ones, Drouin said, adding that the majority of new variant spread has been within families. Drouin, however, said elementary classes at a private school have been closed following an outbreak suspected of involving the U.K. variant.
"This is the first (variant) outbreak that we are seeing," she said. As a precaution, public health is treating suspected cases of variants as though they are confirmed, because, she said, it can take weeks to confirm them and by that time it's too late to act.
Efforts are also being made to more quickly identify suspected variant cases, she said, adding that one laboratory has started screening all positive tests for mutations associated with variants. Not all labs that process COVID-19 results in Montreal have the capacity to screen for variants, she explained.
Drouin said there may be cases of new variants circulating undetected in the city.
"We may be missing some."
While the numbers of new, daily cases and outbreaks reported in the city have declined since early January, Drouin said the downward trend has slowed since schools reopened. Over the past week, she said, the number of new cases appears to have stabilized around 500 a day, which she described as a "high plateau."
The number of outbreaks in health-care facilities and workplaces is trending down, Drouin said, but outbreaks at schools and daycares are increasing.
It's more difficult in big, dense cities to see a drop in the number of cases, she explained, "when we have community transmission and we still have schools that are open.”
Benoit Masse, a public health professor at Universite de Montreal, said it's not clear why the number of new cases reported in Montreal appears to be declining at a slower pace than in other parts of Quebec.
He said people in certain parts of Montreal may be violating health orders or they are being exposed to the virus at work and are bringing it home. It's also possible, he added, that a more infectious variant is driving some of the transmission.
It takes too long to confirm cases of variants in Quebec, Masse said in an interview Wednesday. It took four weeks, he said, to sequence two cases of a variant first detected in South Africa in Quebec's Abitibi-Temiscamingue region.
"Four weeks is a long time on the epidemic scale," Masse said. "We actually don't know in Quebec how the variants are fuelling community transmission right now."
Public health officials reported 499 new cases of COVID-19 in Montreal on Wednesday — more than half the 989 new cases reported that day across the province. The neighbouring territory of Monteregie was the only other Quebec region to report more than 100 new cases, with 137.
The number of new cases is highest in northeastern parts of the city, Drouin said, adding that there are four neighbourhoods where test positivity rates are above 10 per cent: Parc-Extension, Saint-Leonard, Cote-des-Neiges and Saint-Laurent. Across the city, the test positivity rate is 6.6 per cent, she said.
Health officials reported 34 new deaths attributed to the novel coronavirus. They said hospitalizations dropped by 22, to 918, and 148 people were in intensive care, a rise of three. The province said it administered 3,174 doses of vaccine Tuesday, for a total of 266,590.
Quebec has reported a total of 272,726 COVID-19 infections and 10,112 deaths linked to the virus.
This report by The Canadian Press was first published Feb. 10, 2021.
This story was produced with the financial assistance of the Facebook and Canadian Press News Fellowship.
Jacob Serebrin, The Canadian Press