With a sudden spike in cases prompting more people to get tested, Canadians are coping with hours-long lineups at COVID-19 testing centres across the country — and some medical experts are calling on Health Canada to approve new devices to deliver faster results.
Concerned parents and their children faced four-hour waits at Ottawa’s primary testing facility on Monday. A similar scene greeted those looking for a test on Tuesday. At Toronto’s William Osler drive-thru testing centre, residents were kept waiting for more than three hours.
Dr. Theresa Tam, Canada’s chief public health officer, said today that one approach to the crush of people looking for tests could be the deployment of rapid-testing devices. Seven months into this pandemic, these devices still are not available for use in Canada because Health Canada regulators haven’t yet approved them.
“I totally agree with a number of comments from experts that we need to augment the portfolio of testing capabilities in Canada,” Tam told a press conference.
“That’s something we need to press hard at. The regulator at Health Canada has said it’s prepared to work hard to get us tests that are accurate and reliable. I think people are just trying to be careful.”
While she urged caution, Tam said that “right now, I think, is the time to really accelerate getting Canadians this capacity.”
Watch: Dr. Theresa Tam on rapid COVID-19 tests
Tam’s comments come after Dr. David Naylor, one of the country’s leading doctors and a co-chair of the federal government’s COVID-19 task force, urged regulators to give Canadians more testing options ahead of an anticipated fall surge in COVID-19 cases.
“We really desperately need some rapid testing to be done at points of congregation, or points of meetings, so that you can have use of some form of salivary testing or rapid nucleic acid testing, or even antigen testing in schools and work sites. That would really help things here,” Naylor said in an interview with CBC’s Power & Politics on Monday.
A rapid test, or a test that uses antigen technology, can produce results in minutes and can be used in a wide range of settings, such as doctors’ offices, pharmacies, walk-in clinics and long-term care homes.
Some public health experts also have said rapid tests should be sent to schools and some workplaces to offer on-the-spot results in high-risk settings.
The antigen tests — which, depending on the device, use matter collected from a nasal or throat swab — don’t require the use of a lab to generate results.
While much faster, these tests are considered by some to be less accurate than the “gold standard” — the polymerase chain reaction (PCR) testing process currently in use across Canada.
If administered properly, PCR tests are highly accurate, identifying positive cases nearly 100 per cent of the time. Antigen tests are also considered highly accurate but they are not as sensitive as molecular PCR tests run through a lab.
Two new tests approved in U.S.
While Health Canada has been reviewing the efficacy of these antigen tests for months, U.S. agencies fast-tracked two such devices in the summer and they are already in wide use there.
In May, the U.S. Food and Drug Administration (FDA) gave approvals for Quidel Corporation’s Sofia 2 SARS device through an emergency use authorization.
According to the National Institutes of Health, thousands of Quidel analyzers were in place across the United States as of July. The analyzers can give electronic results within 15 minutes. Quidel claims its test has a 96.7 per cent sensitivity rate within five days of the onset of patient symptoms.
In July, the FDA issued approvals for Becton Dickinson’s Veritor System for Rapid Detection of SARS-CoV-2; the devices have since been deployed to 11,000 nursing homes across the U.S. to screen residents and staff. The company said it expects to have the manufacturing capacity for 2 million tests per week by the end of September.
The company also announced Monday that it is investigating complaints about a “small number” of false-positives in some homes.
In August, six states announced a plan to bulk buy millions of tests from Quidel and Becton Dickinson to ramp up the use of rapid antigen testing to help detect outbreaks more quickly.
“With severe shortages and delays in testing … the states are banding together to acquire millions of faster tests to help save lives and slow the spread of COVID-19,” said Maryland Governor Larry Hogan, a Republican, in announcing the multi-state pact.
Both companies behind these devices and a third, Korean-based SD Biosensor, Inc., have applied for Health Canada approvals.
As of Tuesday, all are listed as “under review.”
A spokesperson for the Health Canada said antigen tests “are being prioritized for review … Health Canada continues to review all applications as quickly as possible without compromising patient safety.”
“There’s a whole regulatory process that needs to be obviously respected for all these new tests, and potential new tools in the toolbox. We need to know the right way to use them and in the right context,” added Dr. Howard Njoo, the deputy chief medical officer. “It may well be they don’t perform as well as the PCR.”
But even if these antigen tests are not quite as accurate, Naylor said, they could be a crucial line of defence — and because of their lower cost and faster results, someone could take the test multiple times to weed out errors.
When such tests show someone has COVID-19, he said, that person should be tested again immediately to confirm the result.
“That test will help rule out the false positive. If after those two tests you still got a positive, you say, ‘OK, let’s do a swab or send the swab to the public health lab,'” said Naylor.