B.C. COVID-19 modelling group estimates infections '100-fold' higher than official count
British Columbia's official count of COVID-19 cases is underestimating the spread of the disease in the province by a factor of 100, according to an independent group of researchers.
The latest report from the BC COVID-19 Modelling Group uses blood sample data from Canadian Blood Services and the national COVID-19 Immunity Task Force to estimate the true rate of transmission in the province.
The CITF's data shows that nearly everyone in B.C. has antibodies to SARS-CoV-2 – the coronavirus that causes COVID-19 – either from vaccination or infection, or both. About 50 per cent of the province has antibodies from infection, according to the CITF.
The modelling group's report compares that total to the official case count, which is much lower.
"We know that there's only been about 100,000 reported cases in 2022," said Sarah Otto, a member of the modelling group and a professor of biomathematics at the University of British Columbia.
"To get to 50 per cent of the population infected, that's more like 2.5 million cases in British Columbia, so that shows you that there are a lot more infections happening than the number of reported cases."
Throughout 2022, B.C.'s COVID-19 testing strategy has limited access to lab-based PCR tests, and as home-based rapid antigen tests have become widely available in the province, the demand for lab-based tests has declined.
The B.C. Centre for Disease Control only collects and reports data on PCR test results, however, which has meant a large – and growing – gap between the official case count and the actual number of infections people in the province have suffered.
"We estimate, based on how many people have evidence of a past infection in their bloodstreams, that right now we may be undercounting by as much as 100-fold," she said. "So, if you take a look at the official BA.5 wave, it's not all that high. But magnify it certainly 50-fold, but potentially as high as 100-fold."
Over time, Otto said, the official numbers have been growing less representative of overall coronavirus transmission in the province.
"Fewer and fewer people are actually getting officially tested when they come down with COVID, so, I don't know how much further out of whack this can get, but it's certainly really bad," she said.
Looking at the data released by the BCCDC last week can help illustrate the magnitude of the undercounting.
The centre reported 900 new, lab-confirmed cases, which were detected between July 31 and Aug. 6.
That works out to about 129 new infections per day, or about 2.4 per 100,000 residents.
If the conservative figure Otto cited – that B.C.'s cases are undercounted by 50-fold – is correct, then there were 45,000 new cases during the week in question. That works out to 6,429 new infections per day, or 122 per 100,000 people, a significantly higher concentration.
If the official numbers are off by 100-fold, then the true numbers would be 90,000 new cases for the week, more than 12,800 new cases per day, or approximately 244 per 100,000.
Otto said data on COVID-19 transmission should help people make decisions about their safety, but it's hard to make those decisions if the available data isn't accurate.
"I think it's very important that we be able to make wise decisions about the risks that we take – that we know when to mask, that we know when to limit our indoor social activities," she said. "To make informed decisions, we have to have the information."
Right now, Otto said, people should be masking and avoiding indoor gatherings if they want to avoid getting sick with COVID.
She said the modelling group's latest report shows that the latest wave of infections has peaked in B.C., describing the report as "a lot of good news."
Still, Otto added, the peak happened quite recently, and there's still a lot of COVID circulating in the community, even if the BCCDC's numbers don't show it.
CTVNews.ca Top Stories
BREAKING Iran fires air defence batteries in provinces as sound of explosions heard near Isfahan
Iran fired air defence batteries early Friday morning after reports of explosions near the city of Isfahan, the state-run IRNA news agency reported.
American millionaire Jonathan Lehrer denied bail after being charged with killing Canadian couple
American millionaire Jonathan Lehrer, one of two men charged in the killings of a Canadian couple in Dominica, has been denied bail.
Nearly half of China's major cities are sinking, researchers say
Nearly half of China's major cities are suffering 'moderate to severe' levels of subsidence, putting millions at risk of flooding especially as sea levels rise.
Prince Harry formally confirms he is now a U.S. resident
Prince Harry, the son of King Charles III and fifth in line to the British throne, has formally confirmed he is now a U.S. resident.
Judge says 'no evidence fully supports' murder case against Umar Zameer as jury starts deliberations
The judge presiding over the trial of a man accused of fatally running over a Toronto police officer is telling jurors the possible verdicts they may reach based on the evidence in the case.
Health Canada to change sperm donor screening rules for men who have sex with men
Health Canada will change its longstanding policy restricting gay and bisexual men from donating to sperm banks in Canada, CTV News has learned. The federal health agency has adopted a revised directive removing the ban on gay, bisexual and other men who have sex with men, effective May 8.
Colin Jost names one celebrity who is great at hosting 'Saturday Night Live'
Colin Jost, who co-anchors Saturday Night Live's 'Weekend Update,' revealed who he thinks is one of the best hosts on the show.
Sports columnist apologizes for 'oafish' comments directed at Caitlin Clark. The controversy isn't over
A male columnist has apologized for a cringeworthy moment during former University of Iowa superstar and college basketball's highest scorer Caitlin Clark's first news conference as an Indiana Fever player.
'Shopaholic' author Sophie Kinsella reveals brain cancer diagnosis
Sophie Kinsella, the best-selling author behind the 'Shopaholic' book series, has revealed that she is receiving treatment for brain cancer.