Why aren’t some provinces using rapid tests?
While significantly faster, such products are not as accurate as lab-based tests
The latest COVID-19 tests might be rapid, but Canada’s uptake in using them has been anything but.
The federal government says it has procured 38 million rapid tests, and has so far shipped out about 5.5 million of them.
The provinces have been hesitant to use them. They have concerns that the tests are not as accurate as the gold-standard, lab-based PCR (polymerase chain reaction) test widely used across the country since the start of the pandemic.
Some of the provinces aren’t using them at all right now and others are wanting to study their use further.
Meanwhile, over November, provinces have set record highs for pandemic severity markers like case counts and deaths, and with the worst of the winter months still around the corner, the ongoing second-wave could only just be getting underway.
Widespread access to frequent, rapid tests has been touted by the federal Conservatives and some experts as a key element in reducing the spread of COVID-19 and the need for lockdowns. But the rapid tests currently approved in Canada still require a professional to administer them and cannot be used by an individual at home.
Experts say these rapid tests can be helpful in targeting specific groups and settings to find asymptomatic cases of COVID-19, but what is truly needed is cheap, rapid, at-home testing — something which doesn’t exist yet in Canada.
The research on it continues, and Health Canada has been proactively reaching out to manufacturers asking them to apply for approval, but so far none have done so.
Even south of the border, the U.S. Food and Drug Administration only granted emergency authorization last week to the first at-home, COVID-19 self-detection test. While that may be a bit of good news, the single-use device won’t be widely available until next year, costs about $50 (U.S.), and the company behind it has no plans to expand into Canada.
“The idea behind home testing is literally if people could test each other every day — and call your doctor for a lab test if positive — if we had that in place, we’d have no lockdowns, no quarantine, no pandemic,” said Toronto infection control epidemiologist Colin Furness. “We’d be done.”
The Star spoke to infectious disease, rapid testing and health policy experts to find out what the current state in Canada is for the rapid tests, how they work and what is the best way to use them.
What are rapid tests for COVID-19?
There are two currently being widely used in Canada: the Abbott Panbio antigen test and the Abbott ID NOW test, a rapid molecular test which is similar to the gold standard PCR test.
The PCR test detects the genetic material of the virus and is nearly 100 per cent accurate, while the antigen test detects the protein of the virus and has been assessed as less reliable.
The benefit of a rapid test is the speed of its result. Throughout the pandemic, long wait times for COVID-19 test results have been common, but the downside to many rapid tests is that they aren’t as accurate as lab-based PCR tests.
Abbott said in a statement to the Star that both its tests have been “studied extensively.” The company said the Panbio has a sensitivity — the ability to correctly identify a positive result — of 98 per cent in cases of individuals who showed symptoms within the last seven days, while the ID NOW has a sensitivity of 95 per cent.
Experts have cautioned that
data from testing in the real world can be different than the scenarios in which tests are studied.
According to a recent analysis of current literature by Alberta Health Services, the ID NOW test was found to be between 77 and 80 per cent sensitive under clinical conditions, while the Panbio test was between 73 and 98 per cent sensitive.
“The manufacturers’ specifications for testing kits are often higher than the characteristics seen under real-world conditions,” the analysis said, adding that “the body of evidence for rapid testing platforms is poor.”
Why has the rollout of rapid tests been slow in Canada?
Most provinces have expressed concern about the accuracy of the rapid tests and are still debating how to use them. Some have decided not to use them at all for the time being, while others are first studying their use in pilot projects. This week, Ontario announced a plan for how to use them.
“I think what this shows you is that while Health Canada may have approved the rapid tests, there doesn’t seem to be a ton of confidence behind them,” said Dr. Nitin Mohan, a physician epidemiologist and partner at ETIO Public Health Partners.
Health Canada authorized the first rapid or “point of care” COVID-19 test in late March. In the early months of the pandemic, point of care tests — which must still be administered by health-care professionals — were in limited supply and mainly recommended for use in rural and remote areas where sending tests to a lab would take too long.
The Abbott ID NOW and Abbott Panbio were authorized by Health Canada in late September and early October, respectively. The regulator has so far authorized six point-of-care
tests for use on the public.
Health Canada faced criticism at the time it approved the ID NOW for its slow pace in approving a rapid test that could be more widely used across the country, but its approval came just a few weeks after the FDA granted emergency authorization to another Abbott rapid test. Japan, notably, approved a rapid antigen test back in May.
“The provinces really own the consequences of this, so if I’m a province I’m not sure I want to just rely on a memo from Health Canada,” said Furness of the decision by some provinces to first study the use of the tests further. “It’s the province that has to shoulder the burden. They really ought to hurry up, but I understand their logic.”
Can rapid testing slow the spread of the coronavirus?
While less accurate than the lab-based PCR test, experts say there is a role for rapid tests to play in breaking potential chains of COVID-19 transmission by identifying people who are infected, but asymptomatic. They note that a positive result from a rapid test can then be validated by the lab-based test.
Provinces like Nova Scotia have been doing just that, such as with its recent pop-up site in Halifax for individuals who had frequented bars and restaurants in the last two weeks, but who likely would not have qualified for lab-based testing due to a lack of symptoms.
“We are using it as a tool of public health engagement,” said Dr. Lisa Barrett, an infectious diseases expert and researcher at Dalhousie University. “Yes it is less sensitive, and yes we’re probably going to miss some positives, but don’t forget this is a population of people, 100 per cent of whom were never going to get tested, so we would not have known about these people at all.
“Can we, in real time during a pandemic, get a good sense of what’s going on in the community with active infection? I think it’s a great way of doing it, and I think it’s an underutilized tool because we’ve totally taken away the stress from the usual health care system.”
Furness refers to it as “surveillance testing,” which he argues would be far more effective if Canadians had access to athome testing — something Health Canada has not yet authorized, although research on it continues.
“It’s when you go and try to find cases, to actually try to detect them, and not just sitting back and waiting for sick people to show up,” he said.
But not all agree that mass rapid testing, ideally with athome tests, would be a silver bullet.
They raise “a whole host of concerns that I think that the policy-makers are quite right to think about long and hard,” said Katherine Fierlbeck, a political science professor and health policy expert at Dalhousie University.
The biggest one is that it causes a gap in data collection. In Halifax, for example, where young people were rapidly tested, a record was made of those who tested positive, she said.
“If you have an at-home test and you get a positive result, and you don’t want to quarantine, there’s no record that you’re positive,” she said.
There are also concerns about people using the tests correctly, and whether the they are easy enough to use that human error doesn’t affect the results, Fierlbeck added.
The wide-scale use of an athome tests could also cause a false sense of security in users who test negative and then forgo other measures like handwashing and mask use, she said. “So this whole thing about rapid screening, I see the logic, but the lower the threshold, the more complications rise on a number of different angles.”
Now that the provinces have some rapid tests, how are they being deployed?
Approaches have varied widely. Several provinces have expressed concern with the accuracy of the tests, and those that are currently using them say individuals testing positive with a rapid test will also undergo a lab-based test to confirm the result.
Prince Edward Island says it has no plans for now to use the 10,000 rapid tests the federal government is sending its way, as it’s happy with the performance and turnaround time of the lab-based PCR tests, while New Brunswick says it will likely only be using its allotment in rural emergency rooms for now.
In what Mohan described as a “clever” strategy, Nova Scotia is using its rapid tests at pop-up sites in the metro Halifax area, targeting asymptomatic individuals who have been in latenight establishments in the last two weeks. Many of the province’s recent COVID-19 cases have been in people aged 18 to 35 and related to bars and restaurants.
“It’s folks who are getting the virus at the highest rate but aren’t necessarily inclined to get in line and wait for results,” said Mohan.
Quebec has set up an expert committee and plans to further study the use of the rapid tests before possibly rolling them out by the end of the year in settings including remote regions, health care facilities and schools.
And in Ontario, where Premier Doug Ford lauded the rapid tests this week as a “game changer,” tests will be used in hospitals, assessment centres and long-term-care homes, as well as in some other workplaces as part of a pilot project.
As the Star reported Friday, experts including the head of Public Health Ontario’s microbiology lab have expressed concerns with the accuracy of the tests, and described them as anything but “game changers.”
British Columbia has received 131 Abbott ID NOW machines and 27,000 test cartridges, as well as 576,450 of the Abbott Panbio antigen tests.
Laura Stovel, a spokesperson for British Columbia’s ministry of health, said the province had “high hopes” for the rapid tests it received, but ultimately the tests “do not perform well” right before people begin showing symptoms. This is when people are “sometimes most infectious,” she said.
The plan so far is to deploy the rapid-tests to where there is a “cluster” of people with an illness and where they’d want to determine if it’s COVID-19, she said.
Manitoba and Alberta have deployed some rapid tests to remote and rural areas.
When will Canada get more rapid tests?
The procurement process is ongoing and more rapid tests are scheduled to roll in throughout the remainder of 2020 and into 2021.