A record breaking 1,293 cases of COVID-19 in a single day in B.C.

Dr. Bonnie Henry gives a COVID-19 update in Victoria, B.C. (Province of B.C./Flickr)

 Some 40 per cent of British Columbians infected with the P.1 variant of the coronavirus that causes COVID-19 are in their 20s, provincial health officials announced Thursday.

The variant of concern, which is most commonly associated with Brazil, is one of two variants of concern currently circulating widely in B.C. Along with the other - the B.1.1.7 variant commonly associated with the U.K. - the two variants have replaced many of the other strains responsible for B.C.'s cases, provincial health officer Dr. Bonnie Henry said.

Given this, the province is adapting its strategy for detecting the variants, Henry said. Instead of doing whole genome sequencing on every positive test for COVID-19 that seems variant-related in a screening test, the province will be doing whole genome sequencing for surveillance purposes, to monitor for other variants of concern that may emerge.

"Our strategy moving forward, given this high rate of VoCs that we're seeing in British Columbia, will be to no longer routinely sequence for confirmation," Henry said. "We just assume that those screened positives will be the variants. We assume that anybody who is positive for COVID-19 needs to be treated as if they have one of these highly transmissible viruses."

Going forward, whole genome sequencing will help B.C. understand clusters and outbreaks and determine the proportion of travellers who have variants of concern, Henry said. It will also help monitor for reinfections, vaccine failures and so-called "escape variants," which do not respond as well to immunization efforts.

Both P.1 and B.1.1.7 have caused a slightly higher percentage of hospitalizations than other strains of the virus in B.C., according to Henry's presentation.

Overall, 4.2 per cent of British Columbians who contracted COVID-19 between March 1 and 26 were hospitalized, Henry said in her presentation Thursday.

Among those who did not have a variant of concern, four per cent of people were hospitalized. Among those who had P.1, the percentage of hospitalizations rose to 4.3 per cent, and among those who had B.1.1.7, it rose to five per cent.

Despite the higher numbers of hospitalizations B.C. has seen in recent weeks, the provincial health officer said there hasn't been a significant change in the rate of hospitalizations across age groups.

"We are seeing younger people in higher numbers in our hospitals, but it's important for us to understand if that is higher than we would expect, or if that is because we have increased numbers of people becoming infected and the rate of hospitalization is the same," Henry said.

So far, the rate has remained fairly consistent, she said, adding that the province is monitoring the situation closely.

Henry attributed the higher proportion of younger people contracting the P.1 variant to the circumstances in which the virus is being transmitted, as well as its higher transmissibility.

Most P.1 cases have been found in the Vancouver Coastal Health region, though clusters have popped up in every region except Northern Health, so far, Henry said.

- with files from CTV -