TORONTO — Ontario's group of expert advisers on COVID-19 is recommending health officials implement voluntary rapid testing in settings such as schools and workplaces in areas that reach a certain level of infection.
The science advisory table is advising public health units or neighbourhoods where new COVID-19 cases are near 35 per 100,000 people per week and where there is sustained exponential growth, to carry out weekly voluntary screening of unvaccinated or partially vaccinated people in elementary schools.
Health officials in those areas could also deploy rapid antigen tests in workplaces and congregate settings, the group said in a science brief released Thursday.
If a health unit or area's new daily cases approach 175 per 100,000 people per week, however, "weekly testing is likely not frequent enough to reduce spread effectively," the science table said. In that case, unvaccinated and partially vaccinated people should undergo rapid testing two to three times a week, it said.
Public health units in that situation may also want to look into voluntary testing of fully vaccinated people at the same frequency, the advisers said.
The science brief notes the high accuracy of rapid antigen testing in detecting the Delta variant, which currently accounts for most cases in Ontario. It 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 in the province.
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, the science table said.
"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 science table said it considers rapid testing in elementary schools a priority since students under 12 are not fully vaccinated yet in the province. But it added Ontario could use rapid testing in "many ways" to curb the spread of the virus.
The group's latest advice comes as calls continue to grow for broader rapid testing ahead of the holiday season.
Some workplaces in the province offer rapid tests for their employees, and the government has said children in publicly funded schools will each receive five tests to take home over the December break. Ontario is also planning a holiday blitz of offering pop-up testing in sites such as malls, holiday markets, and transit hubs.
The tests, which provide results in about 15 minutes, are also available for a fee at pharmacies for travel or other asymptomatic purposes.
Critics have argued making the tests more widely available, and free for all to use, would help stave off rising infections, particularly over the December holidays.
On Wednesday, Premier Doug Ford defended his government's approach to COVID-19 testing.
"We're covering the gamut of making sure that people have the test,'' Ford said in a news conference in a Peterborough, Ont., event. "We have a plan, it's a strong plan, and we're going to make sure that we continue implementing that pandemic plan."
A spokeswoman for Ontario Health Minister Christine Elliott said Thursday the province had distributed more than 34 million rapid tests as of Monday, and deploys more than a million to workplaces, hospitals, and other congregate settings each week.
This report by The Canadian Press was first published Dec. 9, 2021.
Paola Loriggio, The Canadian Press