B.C.’s swelling COVID-19 cases fuelled by variants, travel

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The P.1 variant of COVID-19 arrived in the resort town of Whistler in mid-February, brought by visitors from other provinces. The B.C. recreation destination, jammed with restaurants and bars, had been a pandemic hot spot since the Christmas holidays and the new, more transmissible variant quickly took over.

From there, it spread across the province as guests in Whistler returned to their homes on Vancouver Island and elsewhere.

The path of P.1, now a major cause of new COVID-19 cases in the province, shows how travel – international, interprovincial and intraprovincial – swiftly carried the more contagious variant around the province, even as British Columbians were urged to avoid non-essential travel.

First detected in Brazil in January, the P.1 variant has been rapidly spreading in B.C. where rising COVID-19 caseloads have forced hospitals to cancel surgeries and tap into “surge capacity” beds. The variant of concern can spread more rapidly, can cause a more severe case of COVID-19 and may resist current treatments and vaccines.

In an interview, Bonnie Henry, B.C.’s Public Health Officer, said the first P.1 cluster identified in B.C. was in the Vancouver Coastal Health region and was introduced from somebody who had travelled internationally. It spread through one building with multiple different families that had connections with each other and that outbreak was contained.

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After that, two separate introductions of P.1 were identified in the B.C. Interior – which may have had an international travel connection, but contact tracers have not been able to confirm the source. The contact tracing system has been overwhelmed in the past two weeks, making it harder to determine the source of transmission.

Dr. Henry said contact tracers have determined that the P.1 variant was introduced to Whistler from other provinces, and it was not a single source because the mutations, analyzed through whole genome sequencing, varied slightly.

“It was like adding another match to an already burning fire,” she said.

That was mid-February, but B.C. had already identified several clusters of the variant by then.

The Whistler-Blackcomb ski mountains were shut down by the province on March 29, but by then the town, packed with vacationers who were served by workers that are housed in crowded accommodations, had become a central point of spread for the P.1 variant.

New figures released Thursday show that in B.C., where 60 per cent of new COVID-19 cases are variants of concern, the variants are currently split evenly between the P.1 mutation and B.1.1.7, the variant first identified in Britain.

By comparison, the majority of the variants of concern that have been identified to date in Ontario and Alberta involve the B.1.1.7 variant.

Earlier this week, the premiers of Alberta and B.C. discussed possible measures to prevent the variants of concern from slipping back and forth across their shared border. But on Thursday, when Dr. Henry said the pandemic risks are now the highest they have ever been, British Columbia announced no new measures.

“The variants are more transmissible, but the things that stop transmission are the same,” Dr. Henry told reporters.

Last week, Alberta Premier Jason Kenney said someone came back to Alberta after a trip to B.C. and brought the P.1 variant with them. That transmission infected five people, who then infected others – a total of 35 cases including one death and two admissions to intensive-care units. In all, Alberta has identified 135 cases of the P.1 variant.

But tracking the P.1 variant’s spread through B.C. demonstrates there is no single door that could be shut against transmission.

“There is no zero-risk right now,” Dr. Henry said. “We saw a lot of people moving about. And when we move about and make contact with people in another place, we’re bringing the virus with us, and we’re bringing the virus home with us. And that’s where we saw spread of transmission across the province.”

She said a small portion of new cases in B.C. every day are related to international travel. “It’s something that can lead to introductions of new variants.”

But B.C. has deferred to Ottawa to manage screening and quarantine provisions for cross-border travel.

With a report from James Keller

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