Medical experts say Canadians should stock up on rapid antigen tests as we head into a summer with almost no public health restrictions across much of the country. But experts add that a negative result doesn’t necessarily mean someone is in the clear.
Canada is already experiencing a sixth wave of COVID-19 in the weeks following the nationwide lifting of mask mandates and other measures.
But while cases are rising, the availability of public PCR tests has not increased again after being overwhelmed during the Omicron-fueled wave that sent case counts skyrocketing in January and February.
“I think most Canadians need to be careful about using the rapid test at home,” said Dr. Prabhat Jha, a global epidemiologist at St. Michael’s Hospital in Toronto.
When should I use a rapid test?
Jha recommends people use a rapid antigen test when they start showing COVID-19 symptoms or if they have been exposed to an unvaccinated or symptomatic person with COVID-19.
Even then, he says, not all situations would require testing.
Instead, Jha suggests considering: “Was the person I was in contact with vaccinated? Was the person actively symptomatic?
A positive result can also help an infected person have a better picture of the risk to their family members and others around them, especially when mask requirements are lifted and other respiratory viruses start to circulate more widely, Dr. Susy Hota, Medical Director of Infection Prevention and Control at the University Health Network in Toronto.
Regardless of a positive or negative result on a COVID test, both doctors say a person who has a respiratory illness should isolate themselves from others until they are feeling better. They also prevent transmission of colds and flu.
What does a negative result mean?
Medical experts continue to warn that a negative result on a rapid test doesn’t necessarily mean you don’t have COVID-19. New Swiss researchwhich has yet to be peer reviewed suggests that some rapid tests have “significantly lower sensitivity” to Omicron than to the Delta variant.
Similar, Research from Ontario’s COVID-19 Science Advisory Table Earlier this year, rapid tests in nasal samples were found to be less sensitive to Omicron than the Delta variant, particularly in the first day or two after infection.
Doctors now recommend isolating immediately after symptoms or exposure and then waiting a day or two before using a rapid test to get the most accurate result possible from a rising viral load.
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“At this point, the rapid tests are less likely to give a false negative,” says Jha.
But it can still happen, says Hota, who recommends taking another rapid test 24 hours later, noting that a second negative test “doesn’t necessarily rule that out.”
However, she adds, a positive result should always be accepted as a true positive.
Should I do a quick test before an event?
As spring and summer social calendars fill up, both Jha and Hota said it’s important to remember that a negative rapid test result is never a guarantee – and that other safety measures, like holding events outdoors, still do are important.
“A single rapid test tells you what your status is at the time you take the test with little sensitivity,” Hota said.
“If you have the virus, it’s theoretically possible that you might be less contagious to others at that point. It could change again in the two hours you’re in this place…but it’s just not something to hang your hat on.”
Jha points to a recent gala in Washington, the Gridiron Dinner, as a case in point: more than 10 percent of the 630 guests at the maskless indoor event — including cabinet secretaries, members of Congress and White House advisers — have since tested positive.
However, according to Jha, rapid tests can be useful in determining when you’ve recovered enough to return to work and socialize again, “usually five days after you had the first positive test or symptoms started.”
“If it’s gone negative by then, you’re pretty much free to meet up with others.”
What is the best technique for a test?
The technique you use to give yourself or someone else a rapid test also plays a big role. And experts say a quick sweep around each nostril is no longer enough, despite the box directions.
For a more accurate result, Hota recommends dabbing the undersides of both cheeks, then the throat, tonsils, or back of the tongue — “depending on what you can tolerate” — and then dabbing both nostrils. The swab should go about 2 centimeters into each nostril for several circles, she said.
How many test kits should I keep at home?
Jha suggests making sure you do at least two tests per household member. “If you’re a typical family of four, maybe you should have 10 on hand.”
But how easy or difficult it is to get your hands on a free rapid test depends on where in Canada you live, with provinces and territories distributing them through different channels.
In British Columbia, for example, rapid tests are available for free at pharmacies, but those stores say they’re having trouble convincing people to take them.
Raj Rakholiya, a manager at Wilson Pharmacy in Port Coquitlam, BC, says uptake is increasing as cases increase, but it’s still falling short of expectations: He’s currently sitting on a stockpile of about 550 test kits.
“Most people say they’ve already got their three shots, now they’re going to book for their boosters, so they don’t need them. Some people say they already have COVID, so they’re less likely to catch the virus again, so they won’t get it [tests].”
Infectious disease specialists say this is the wrong strategy: Thousands of Canadians have contracted COVID-19 more than once, and reinfections are becoming more common as the more transmissible omicron subvariant BA.2 spreads in Canada.
“Although the risks are small, you can get infected again even if you have had COVID before,” Jha said.
“Having rapid tests at home I think is a sensible strategy that’s seen as a kind of new normal.”
Where to Find a Free Rapid Test in Your Province or Territory:
British Columbia: Available in pharmacies
Albert: Available in packs of five at select Alberta Health Services pharmacies and clinics
Saskatchewan: Available at libraries, select grocery and gas stations, some municipal offices, and other locations throughout the province
Manitoba: Available at provincial testing sites, pharmacies and grocery stores throughout the province, and libraries in Winnipeg
Canada: Available at some grocery stores, pharmacies, and community organizations
Quebec: Available in most pharmacies as well as in schools and childcare facilities (for registered families)
Prince Edward Island: Available at provincial entry points, access to PEI sites, schools and day care centers (for enrolled families) and some community organizations
Nova Scotia: Available at MLA offices, Access Nova Scotia locations, public libraries, family resource centers, some food banks, and pop-up sites
Newfoundland and Labrador: Limited distribution through schools, health centers, residential communities and other select entities
Yukon: Available at some stores in Whitehorse and at community offices in other parts of the territory
Northwest Territories: Available at Yellowknife City Hall and Field House, as well as other area grocery stores
Nunavut: Available in Northern and Northmart stores