Why health experts discourage 'hacking' rapid tests with throat swabs

Health experts are discouraging people from using self-administered rapid antigen COVID-19 tests in their throats instead of their noses.

The hack is gaining popularity on spaces like TikTok, where some users have uploaded videos of themselves using a rapid test in their nose and getting a negative result, but then doing it again in their throat and getting a positive result.

"Right now, I don't recommend people start swabbing random parts of their upper head and neck, including the throat, until we get those data out there, and, hopefully, we should have some of that soon," Dr. Lisa Barrett, an infectious disease specialist, told CBC's Information Morning Halifax on Friday.

Barrett said she's aware that the trend is gaining popularity. She said the hack is being tested in multiple control groups across Canada, including at a lab in Nova Scotia.

But until there is verification, Barrett and Nova Scotia's Department of Health and Wellness say people should continue to use the self-administered nasal swabs as directed.

During an interview with The National earlier this week, another infectious disease expert, Dr. Zain Chagla, noted saliva could prevent a test kit from working properly.

'Not all kits are meant to do saliva'

"Not all kits are meant to do saliva and so you really want to make sure that's within the guidelines of your kit. Otherwise you may get a negative result when you're aiming to get a positive result and making behavioural changes based on that," Chagla said.

In an email, Dr. Glenn Patriquin, a member of the microbiology team at Nova Scotia Health, said self-administered rapid antigen tests like the ones in Nova Scotia are specifically designed for nasal swabbing.

Patriquin said people should wait for the science before swabbing the throat with a rapid test.

"People should really accurately follow the directions provided, unless we get direction to change collection from the test manufacturer, from Health Canada, or through some other means supported by data," he wrote.

Rapid tests are in short supply in many parts of Canada, but more are on the way. Ottawa announced early this week it 140 million rapid tests would be delivered to provinces and territories this month.

Nova Scotia Public Health said Friday that if someone does test positive using a nasal swab on their throat, they should treat it as a positive case.