An outbreak involving a COVID-19 variant at an apartment building in North Bay, Ont., grew to 31 cases Tuesday as public health authorities probing a cluster of variant cases at a southern Ontario condo said such situations highlighted the far more contagious nature of the new strains.
The North Bay Parry Sound District Health Unit said an outbreak declared last week at the apartment building had grown by two more cases since its last update on the situation over the weekend.
Of those who've been infected, 20 have tested positive for a variant of COVID-19 -- one of those has been identified as the variant first detected in South Africa while further testing is underway to determine the strain involved in the others.
North Bay's top doctor has urged residents to stay home and follow public health guidelines as authorities probe how the virus spread in the building.
Further south, public health authorities in Peel Region were investigating a cluster of variant COVID-19 cases at a condo building in Mississauga, Ont.
The local health unit said it conducted floor-by-floor testing of residents on Monday in an effort to prevent community spread after finding five cases of the variant that emerged in South Africa.
The region's top doctor said the health unit was investigating whether there was transmission of the more contagious variant in common areas such as elevators, stairwells and hallways.
Dr. Lawrence Loh said authorities are also looking at the building's ventilation and other factors.
"This and other variant outbreaks, including the one in North Bay, should really give all of us pause," said Loh.
"We know that as the variants are here and being detected in alarming frequency, we really do need to also reconsider the whole context and picture has changed as well."
One epidemiologist said it's not known how much of a factor ventilation plays in the spread of COVID-19 variants in such cases.
Dr. Peter Juni, a professor of medicine at the University of Toronto and the scientific director of Ontario's COVID-19 science advisory group, said those who look after such buildings should make sure that all common areas are as well ventilated as possible.
Ventilation systems should also be maintained and air conditioning filters should be changed frequently, he said.
The more contagious nature of variants means COVID-19 prevention measures that have worked before may not work as efficiently now, he said.
"They still work in principle but we might need to get more strict," he said.
"The rules for control of this pandemic are about to change."
This report by The Canadian Press was first published Feb. 16, 2021.
This story was produced with the financial assistance of the Facebook and Canadian Press News Fellowship.
Denise Paglinawan, The Canadian Press