The mandatory measure, which affects about 1 in 20 fully vaccinated people entering Canada by air, also results in healthy travelers being forced into quarantine. The tests used — PCR or molecular tests — are too sensitive to tell the difference between active infections and past infections.
Read more: Experts warn ArriveCAN app may violate constitutionally protected rights
But the government insists on using these tests because it says they are the “gold standard” for detecting the virus, even if they can catch people who have fully recovered from it. Story continues below ad “You’re shooting a dart blindfolded,” said Colin Furness, an infectious disease expert and epidemiologist at the University of Toronto. “I want us to do disease surveillance. I want us to do transmission control … but I don’t think their current plan is actually very effective at either of those things.” 2:13 Mandatory random COVID testing of international travelers entering Canada resumes Mandatory random COVID testing of international travelers entering Canada continues – July 19, 2022 Mandatory random testing of fully vaccinated travelers began in late 2021 to help monitor the spread of new variants entering Canada and ensure infected travelers are quarantined. About 5,000 people are selected each day, according to the government. The tests are being carried out by a handful of private companies that have received hundreds of millions of dollars in government contracts since the start of the pandemic. The random tests were widely criticized this spring as a source of unprecedented disruption at Canada’s airports. Critics said it led to congestion at customs checkpoints, which created back-to-back problems leading to flight delays and cancellations. Story continues below ad The government suspended testing at airports in mid-June to ease some of those pressures. However, to continue to monitor new variants, he restarted the program a month later, with tests either done on their own at home or completed at non-airport locations.
Read more: Ottawa’s move to end random COVID-19 testing ‘welcome news’ for Canada’s airports
Denise Chenier, who lives in San Francisco and recently traveled to Canada with her husband, Grant, was one of those chosen to test at Toronto’s Pearson Airport after the program restarted. The couple were flying to Thunder Bay to settle Grant’s mother’s estate and celebrate her life. The Cheniers arrived in Thunder Bay on a Saturday in late July, the same week that random testing began again. Denise completed her PCR test the following Monday, when she said she opened the government-contracted lab. He said many days passed without getting the results. When she contacted public health officials to get the results, she said she was shocked to find out it was positive and that she had to self-isolate for 10 days. “I read it and thought, ‘That’s a typo,’” Denise said. 2:24 Concerns Grow Over ArriveCAN App Violating Constitutional Rights Concerns Grow Over ArriveCAN App Violating Constitutional Rights – August 10, 2022 The couple had recently recovered from COVID-19 and had tested negative for multiple rapid antigen tests completed during a 12-day isolation period prior to their trip. Story continues below ad They said it was unlikely they were reinfected with the virus before traveling because they limited contact with others, wore masks at all times and had two booster shots each. They also said they ran rapid antigen tests after arriving in Thunder Bay and the results were negative. The couple said they explained their situation to local, state and federal health officials over the phone, all of whom agreed the test likely picked up on Denise’s previous infection. But rules are rules, Denise said she was told, meaning she still had to go into quarantine. “It was a huge imposition,” Grant said. “Waste of time and money.” The government said all fully vaccinated travelers entering Canada have an “equal chance” of being selected for random testing. It doesn’t matter what country a traveler comes from, how long they’ve been away or if they’ve been selected for testing before. Trending Stories
Diagolon: What you need to know about the team whose founder shook Pierre Poilievre’s hand ‘Mind’: Big and small across Canada struggle amid staffing crisis
Story continues below ad The government said its daily target of around 5,000 tests was set to make sure it had a “representative, reliable and robust estimate” of the number of people who are positive for COVID-19 at the time they cross the border. But the government also said its tests can detect past infections for up to 180 days, meaning many of the positive test results could be old infections, as opposed to active infections.
Read more: Pearson slow to improve but still less than half flights on time
To avoid potential problems, including forcing people with previous infections into unnecessary isolation, anyone who provides a positive PCR test result up to 180 days before entering Canada is excluded from the random testing program. However, access to PCR tests has been restricted in many places over the past year, meaning travelers with previous infections are unlikely to be able to provide the proof they need to get an exemption. 2:04 COVID-19: Quebec reserves PCR testing for high-risk groups COVID-19: Quebec reserves PCR testing for high-risk groups – January 5, 2022 The Cheniers, for example, were told by their family doctor not to bother with a PCR test because they had many symptoms of COVID-19 and tested positive on rapid antigen tests. Story continues below ad The couple said they support border testing, but believe the exemption from random testing should be extended to anyone who previously tested positive on a rapid antigen test. In Ontario, meanwhile, access to PCR testing was limited to “high-risk” people in December 2021. Anyone not considered high-risk who had symptoms of COVID-19 was told to “assume” they had the virus without getting infected a PCR test. The provincial government also expanded access to rapid antigen tests through workplaces and pharmacies. James Hay, a postdoctoral researcher at Harvard’s Center for Infectious Disease Dynamics, said it is “extremely unlikely” that someone would test positive for COVID-19 six months after infection. He said research has shown that most people will start showing negative results on a PCR test between 10 and 14 days after infection.
Read more: Ontario changes PCR test eligibility for COVID, isolation eases for fully vaccinated to 5 days
Hay also said that rapid antigen tests, which are less sensitive than PCR tests, would be a more effective tool for identifying active cases of COVID-19 at the border. “An antigen test is actually very specific for that potentially infectious period because you have to have a lot of virus for the antigen test to be positive,” he said. Story continues below ad A useful method for doing this would be to give travelers two or three rapid antigen tests and have them complete the tests over several days, Hay said. Anyone who has repeatedly tested negative will likely not be infected with the virus, Hay said. Those who test positive are likely in the midst of an active infection and can be monitored. “There’s definitely a role for testing, it’s just where it’s done and how often it’s done that probably changes,” Hay said. A major benefit of using the PCR test is that it allows for “sequencing” of the virus, which is necessary to distinguish between different variants, Hay said. This allows the government to track the spread of emerging variants, such as Delta and Omicron, and potentially deter any serious threats to Canada by imposing new public health measures. Story continues below ad This could include restricting flights from countries where data shows more contagious and potentially deadly variants are spreading or imposing stricter quarantine measures on international travelers. “It could be an early warning sign,” said Caroline Colijn, a professor of mathematics at Simon Fraser University and an expert on the evolution of infectious diseases.
Read more: Health Canada warns of fake COVID-19 antigen tests in Ontario
Colijn, who sat on the federal government’s COVID-19 expert advisory group, said it was important to understand the goals of any testing regime before determining its effectiveness. In terms of tracking new variants, he said, the government’s strategy of random testing at the border is useful. But when it comes to preventing the spread of the virus, the strategy doesn’t…
