P.E.I.'s new rapid test guidance to include option to swab both nose and throat

The Chief Public Health Office is making plans to update its guidance on rapid testingto include the option to swab both your throat and nose.

It's a change in recommendation that Nova Scotia Health made last month, after researchshowed nasal or throat swabs on their own detected 64.5 per cent of cases.But combined swabbing of the nose and throat increased the test sensitivity to 88.7 per cent. PCR tests were used to confirm those results.

Dr. Todd Hatchette, head of Nova Scotia Health's microbiology teamand a professor in Dalhousie University's department of pathology and laboratory medicine,led the research.

"There were lots of anecdotal reports of people saying that the nose swab using rapid antigen test was not picking up cases and when they swab their throat, it was," said Hatchette.

"But there was no real rigorous data to try and support that claim, so we went out and tried to prove or disprove whether that was the case."

Testing was conducted in community settings, with nearly 1,500 asymptomatic individuals.

Why more effective?

He said it's not yet clear why swabbing both the throat and the nose is a more effective way to detect COVID-19.

"There is some data to suggest that perhaps Omicron likes to grow initially in a different place, so maybe it likes the back of your throatmore so than the front of your nose, and maybe it takes time to transition to that area of your respiratory tract," saidHatchette.

"No one's really sure at this point, but itdoes offer an opportunity to increase your rate of detection if you combine."

He said the efficacy of swabbing both the throat and the nose hasn't yet been tested on symptomatic individuals,but he suspects there would be an increase in their COVID-19 detection rates as well. He said when it comes to PCR tests, adding the throat swab doesn't appear toincrease detection.

WATCH: A visual aid to swabbing your nose and throat for a rapid test

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Nova Scotia Public Health is now recommending those who use rapid tests to swab their nose and their throat with the same swab when collecting their sample.

"We did this same project looking at our PCR tests. Again, the question is: if we saw this difference using antigen tests, would wesee the same with PCR tests?" said Hatchette.

"So it was slightly different in that we compared a throat/nose combination with the deeper nasopharyngeal swab. And in that circumstance, we didn't find any significant difference between the two, suggesting that both swabs can be continued to use to detect Omicron."

Officials with P.E.I.'s Chief Public Health Office saidthese findingshave been a topic of discussion this weekand confirm rapid test guidance in this province will soon be updated to include the combination throat/nose swab option, which they say increases the sensitivity of the test.

"It is important to note it is not a throat ora nasal swab, but rather a nasal or a combined throat and nasal," said an official, addingmore details on this new guidance will be shared next week.