Canada should follow Slovakia's lead
Rapid testing key to mastery of virus prevention
OTTAWA • Canada should follow Slovakia's example in enabling widespread, frequent rapid testing to the population to screen themselves for COVID-19, a House of Commons committee heard Monday.
Martin Pavelka, an epidemiologist with Slovakia's ministry of health, told MPs on the Commons health committee that Slovakian citizens are now asked to get a rapid antigen test at least once per week and must show a recent negative result if they want to enter a workplace or certain businesses such as a bank or post office.
The country of 5.5 million people, which suffered a devastating second wave over the winter driven by the highly transmissible British variant, has used widespread rapid testing to help bring the virus under control.
Lab-based PCR testing, the backbone of Canada's testing system, is extremely accurate at detecting the virus (even well after a person has stopped being infectious). Rapid antigen tests are less sensitive, but they can be done on site, are easy to use and take about 15 minutes to get a result, depending on the device. They are much cheaper and less resource intensive to operate than PCR tests.
Since being implemented in late January, rapid test screening has detected almost twice as many cases in Slovakia as lab-based PCR testing, Pavelka said, adding that about half the cases were found in asymptomatic people. Despite having a vaccination rate similar to other European Union countries, Pavelka said that widespread rapid testing has helped them lower their infection rate faster than their neighbours this spring.
“The limited laboratory capacity meant that only symptomatic people were basically favourites for the PCR test,” Pavelka said. “On the other hand, with the antigen tests you can scale them up, they have low cost, you can do them at high frequency. And you can actually cut more chains of transmission.”
Slovakia has been on the forefront of rapid testing since last fall, when it famously rapid-tested most of its population over two weekends, and found 50,000 positive cases. “This (took us) by massive surprise, no one expected that,” Pavelka said. “And I think that's when it hit everyone: it is everywhere, and anyone can be a carrier.”
But that campaign was a one-off, and Slovakia was later hit with a huge wave of cases that left the country with a much higher per capita COVID-19 death rate than Canada.
Since bringing in the sustained rapid testing campaign, Pavelka said they've learned some lessons about how to do it right. For one thing, he said isolating only the person who tests positive doesn't work with the variant; it spreads so quickly that you need to isolate the whole household immediately to break the transmission chain.
He also said effective communication around rapid testing is very important. People need to understand what it can and can't do. But he said Slovakia's experience in processing millions upon millions of rapid tests shows that the concerns around rapid testing's accuracy are overblown.
“People don't trust the antigen test because of the lower sensitivity,” Pavelka told the MPs. “But the point of antigen mass testing is not to accurately detect the infectious status of every resident. That's not the point. It's not a clinical test. The point is to detect enough chains of transmissions, and by cutting them, to flip the reproduction number below one. That's all you need. By switching that, the epidemic will be decelerating.”
Dr. Isaac Bogoch, a Toronto-based infectious diseases physician, told the committee that he is very encouraged by the “tremendous innovation and work” that Slovakia has done with rapid antigen tests.
“These are excellent tests that have been underutilized in Canadian settings,” Bogoch told MPs. “We have access to them, we just haven't deployed them as broadly as we should have.”
Bogoch said he also believes the concerns around the sensitivity of rapid tests are misplaced, and supports their use to help keep workplaces open.
“I'd much rather use a rapid test and detect most of the people coming in who are positive for COVID-19 by using these rapid tests, rather than detect zero people coming in by not using any rapid tests,” he said. “It's a kind of a no-brainer.”
Canada will soon have more evidence it can examine around the effectiveness of widespread rapid testing, as the United Kingdom is now offering free rapid tests for all its citizens to take at home twice weekly.
Although Canada's rollout of rapid testing has been very slow due to strict regulations imposed by skeptical provincial health authorities, that situation is starting to change. Nova Scotia has been heavily using asymptomatic rapid testing to get its recent outbreak under control. Ontario announced last week it's sending out 760,000 rapid tests to local chambers of commerce, with the aim of twice-weekly screening for small and medium businesses; more provinces are expected to follow suit in the coming weeks.