TORONTO — Rapid COVID-19 tests can help stop transmission and could be valuable tools in workplaces and schools, Ontario experts said Thursday, while Quebec announced test kits for kids amid calls for their expanded use.
The Ontario science advisory table issued new advice on the use of rapid antigen tests Thursday, noting their high degree of accuracy in detecting the Delta variant, which currently accounts for most cases in Canada.
People infected with the Delta variant reach a peak viral load earlier than previous variants, often before symptoms emerge, the document said. That's what makes the variant more contagious than the ones that came before it, but also what makes rapid antigen tests more accurate in detecting it.
"Rapid antigen tests could therefore help interrupt the chain of transmission by identifying infectious cases of COVID-19 quickly, leading to prompt isolation of the infected person," the group said.
"Rapid antigen tests may also present a valuable alternative to individual isolation after exposure in schools. Implementing voluntary 'test to stay' protocols, where exposed students remain in school as long as daily tests are negative for SARS-CoV-2, could help prevent the harms of isolation without increasing transmission."
The group's latest advice comes as calls grow for broader rapid testing ahead of the holiday season to help ensure safe gatherings.
Dr. Fahad Razak, an author of the science brief, said rapid tests have a role in school settings, workplaces, but also before holiday gatherings.
"They're part of a strategy," Razak said in an interview Thursday afternoon.
"So the PCR tests still have a really important role, they are the confirmatory tests, they're the test you do when you think you're sick. But these rapid tests have an important role in allowing us to do as many day-to-day activities as possible."
Razak noted that people can use a rapid test "immediately before getting together" and if everyone tests negative for COVID-19, they can have some assurance that they're going into an environment with a lower risk.
Currently, some workplaces in the province offer rapid tests for their employees, and children in publicly funded schools in Ontario will each receive five tests to take home over the December break. The tests, which provide results in about 15 minutes, are also available for a fee at Ontario pharmacies for travel or other asymptomatic purposes.
The tests are used more in some international jurisdictions, and more often in some Canadian provinces. Saskatchewan offers rapid tests for free to the public for take-home use. On its website, Saskatchewan said kits of five tests are available on a first-come, first-served basis, with one kit per household at this time.
In Nova Scotia, residents are able to get free rapid tests from pop-up locations across the province for at-home testing. Dr. Lisa Barrett, the lead of the province’s rapid testing program, said in an interview Thursday the province has been using some version of take-home testing since late May this year.
While it’s not the only factor in the province’s “relative success” in keeping cases low, she said it has set Nova Scotia apart from other jurisdictions.
“This idea of a no-symptoms-testing strategy, especially when led by community members and volunteers either doing or distributing the tests is very different and, to my knowledge, not being done routinely in most of Canada,” she said.
“I think that's one of the most effective things we've done here is to generate that culture of de-medicalized testing,” Barrett added, which she said has allowed residents to more actively participate in keeping themselves and others safe during the pandemic.
Razak said Nova Scotia has set a "great example" that Ontario and the rest of the country can follow, noting they should be more "widely distributed" in higher-risk settings.
"I think there's an opportunity for the rest of Canada to do that as well and to just more widely use these tests," he said.
The Ontario science advisory table is recommending health officials implement voluntary rapid testing in settings such as schools and workplaces in areas with higher transmission, as often as two to three times a week in some situations.
The recommendations focus on testing unvaccinated or partially vaccinated people, but say that in areas where new daily cases approach 175 per 100,000 people per week, it could be offered voluntarily to vaccinated people as well.
The brief does not examine the use of such tests to detect the new, potentially dangerous Omicron variant, of which there are presently dozens of confirmed cases across the country.
Ontario expanded its rapid testing program for schools in October to allow students to do regular tests over 10 days in cases where the school could otherwise face closure due to high cases. The government said Thursday some 170,000 rapid tests have been distributed to schools through its program targeting high-transmission areas and its general rapid testing efforts for schools.
The province is also planning a holiday blitz of offering pop-up testing in sites such as malls, holiday markets, and transit hubs. Overall, Ontario has distributed more than 34 million rapid tests, the government says.
Quebec unveiled its own plan for school-age children Thursday, saying three million rapid tests would be distributed to preschool and elementary school students. The tests are meant to be used at home to check whether children who show symptoms of the virus are infected.
The announcement came as the province recorded its highest number of daily cases since mid-January — 1,807 new infections.
Ontario, meanwhile, reported nearly 1,300 new cases on Thursday, the highest tally since late May.
Ontario Premier Doug Ford has repeatedly defended his government's approach to COVID-19 testing.
"We've had a robust plan ... that focuses on making sure that we're focusing on getting people to the testing stations, getting people to get a rapid test," Ford said Thursday in the legislature.
- With files from Danielle Edwards and Noushin Ziafati
This report by The Canadian Press was first published Dec. 9, 2021.
Paola Loriggio, The Canadian Press