B.C. has completed 39 pilot projects on its available COVID-19 rapid testing technologies, including at seven outbreaks in long-term care facilities to screen employees who are not showing symptoms.
Provincial health officer Dr. Bonnie Henry responded this week to repeated calls for more widespread use of rapid testing, describing how nasal swabs and rapid result machines have been used in provincial prisons, workplace outbreaks and in B.C. schools where exposures have taken place. Results have not been encouraging.
“Of the thousands of tests that have been done, two of them have been positive, and both of those cases were in facilities that were having an outbreak,” Henry said at a COVID-19 briefing March 4. “So if our community transmission rates are low, screening with these less sensitive tests is not very effective. It doesn’t help us because the yield is so low and they have a very much higher false-negative rate. In those areas where we have an outbreak or where community transmission rates are higher, that’s when they might have more utility and those are the areas that we are looking at more closely.”
B.C. started receiving Health Canada-approved rapid tests in late October, but each batch required validation by a B.C. Centre for Disease Control lab, before pilot projects could be done. The first school test was at Garibaldi secondary in Maple Ridge, where a new variant of the SARS-CoV-2 virus turned up in the more accurate genetic testing used for diagnosis.
“There are two situations that we use them in,” Henry said. “One is for testing of people with symptoms to determine whether they might have COVID or something else. This has been very helpful in situations where people have had a test three days before they go for surgery and the day of their surgery they have a bit of a cough or runny nose.”