Rapid tests more important than ever in COVID-19 fight, says expert

An infectious diseases doctor and researcher at Dalhousie University in Halifax says rapid tests are more important than ever because the level of COVID-19 in New Brunswick and other regions is so high.

Dr. Lisa Barrett says the tests, which can be used at home, providing results within about 15 minutes, are a useful tool for detection.

"The take-home message with any test like this is that a negative doesn't tell you a ton, but a positive is really helpful in getting you to understand that you're positive and need to stay home.

"I guess the take-home also is if you have symptoms but your one-time … rapid test is negative, until you're 48 hours out and you can repeat that, you should consider that you still might be infectious with COVID or something else" and should stay home, she said.

On Tuesday, the Green Party called on the New Brunswick government to make rapid tests more accessible before Easter weekend so people can gather knowing they won't be putting anyone at risk and the province can avoid a spike in cases.

"New Brunswickers will have access to rapid tests for the upcoming Easter weekend," Department of Health spokesperson Bruce Macfarlane said in an email Wednesday.

Distribution sites will be operational Good Friday and Easter Monday in Moncton, St. Stephen, Sussex, Saint John, Fredericton, Edmundston, Campbellton, Bathurst and Miramichi, while the Woodstock distribution site will be open Easter Monday, he said.

Access to rapid testing has been limited in the province since January.

Only people with COVID symptoms are eligible and they must book an appointment online to pick up a free rapid test kit at one of 50 Horizon and Vitalité assessment centres.

Nova Scotia provides free access to rapid tests to anyone who wants them and makes them available in various public locations, including libraries and MLA constituency offices.

Barrett estimates her province hands out about 750,000 tests each week.

By comparison, New Brunswick distributed 1.9 million rapid tests through assessment centres in the month of December, according to the Department of Health.

And some people have had to wait up to four days for an appointment.

Health Minister Dorothy Shephard said Tuesday the government will "look at" increasing the number of distribution sites "for convenience," "where appropriate," but did not provide a timeline.

Helpful before visiting vulnerable people

Barrett said many jurisdictions suggest people with symptoms use rapid tests, which is "a great way to use them," particularly for people who don't have nearby access to PCR (polymerase chain reaction) lab tests. 

But rapid tests can also be helpful if asymptomatic people use them right before they go to visit someone considered vulnerable, either due to a medical condition or because they're unvaccinated, she said.

"Does it mean you're definitely not infected if you get a negative? No. Does it mean you're likely far less infectious? Yes. And then you would also know if you were positive and shouldn't go."

The tests should be used immediately before the visit, Barrett advised, because the Omicron variant is "pretty sneaky."

"You can go from being negative to pretty positive the next day, within 12 hours. In fact, that's my personal story. And I hear it from many people."

Anyone with COVID-like symptoms should not go to visit people who are vulnerable, stressed Barrett.

"Everyone tells me it's their allergies and yup, that could be true. But right now, with the amount of virus around, please be aware, it could also be COVID and you could be spreading it to someone else," she said.

"Please don't go and hang out with those people over the holidays."

What affects results?

Several other factors can affect the reliability of rapid test results, said Barrett. One of them is when people test.

If people are very early or later in their infection, it might be more difficult to pick up the virus, she said.

Similarly, if people are fully vaccinated and don't have many symptoms, they might have low virus levels, which could be missed one day but picked up the next.

The more frequently someone takes a test, the higher the likelihood that a negative result is truly negative, said Barrett.

Another factor is the quality of the sample collected, she said.

How to collect the best sample

To ensure the best sample, Barrett advises using a test kit with a swab long enough to reach the back of the throat. 

People should swirl the swab five or six times on each side of the tonsils. "You really need to get back there. And if you don't have a little bit of a gag response, then you're probably not quite there," she said.

They should then swab each nostril, making sure the entire fuzzy part of the swab makes contact.

Next, the swab goes into the fluid that comes with the kit. "You've got to swirl it around and really wring out the tip of that swab in there."

It should sit in the fluid for roughly 10 to 15 seconds, whatever the manufacturer instructions indicate, before being dropped on the test, said Barrett. "If you do it too fast, you're going to miss some virus." 

Although the province limited access to rapid tests in January to people between the ages of two and 49 with COVID symptoms, Department of Health spokesperson Bruce Macfarlane told CBC Tuesday that's no longer the case.

"Tests are available to anyone that wants them regardless of their age," he said in an emailed statement. "Public Health's only requirement for rapid testing is for an individual to have symptoms of COVID-19."

In addition, people 50 and older, who are targeted for PCR lab testing, may opt to pick up a rapid test kit instead during the online registration process, Macfarlane said.