(BCCDC COVID-19 testing)

The preprint of a new study that is awaiting peer review shows the results of British Columbia’s first serology testing.

The study was conducted by researchers from the BCCDC, University of British Columbia, Public Health Agency of Canada, and Lifelabs, alongside Provincial Health Officer Dr. Bonnie Henry.

Its findings indicate that less than 1 per cent of B.C.’s population was infected with COVID-19 by May 2020, which is when some of the restrictions started to lift as the transmission rate remained flat for several weeks.

Serology testing revealed that the number of people who had actually contracted the virus were far higher than the number of people who tested positive for COVID-19 in the early months, as asymptomatic and some symptomatic patients went untested due to the province’s shift in testing strategy.

See also: B.C. will start trialing “promising” antibody tests on recovered COVID-19 patients: Dr. Henry

“Until early April…BC targeted SARS-CoV-2 testing to people with exposure and/or high-risk indication, leading to a per capita testing rate that was also below other provinces,” reads the study.

“…statistics have led to speculation that BC may have experienced more undocumented SARS-CoV-2 infections that, in conjunction with asymptomatic cases, contributed to unrecognized community transmission.”

This initial serological testing focused on the Lower Mainland—Greater Vancouver and the Fraser Valley—and estimates that about 16,500 people were infected with the virus—a number that is eight times higher than the 2,000 test-positive cases that were officially reported in the same time frame.

Nevertheless, B.C. has been hailed as one of the most successful regions of the world in suppressing the spread of the virus and quickly flattening the curve through a range of public health measures enforced by the Ministry of Health.

“This success, however, constitutes a double-edged sword, further highlighting substantial residual susceptibility,” the paper continues, keeping alive the reminder that the pandemic is not over.

Next week, on Monday July 20, Provincial Health Officer Dr. Bonnie Henry is expected to provide a more detailed analysis of these findings and what they mean in terms of future public health policies in B.C.

Serological tests are diagnostic blood tests used to determine whether an individual has developed antibodies in response to an infection.

Back in April, Dr. Henry indicated that further serological testing for other cross sections of the population in B.C. were planned for early May with a second test in six months, in order to give time for the antibodies to develop.