The Therapeautic Goods Administration (TGA) has updated its advice on using rapid antigen tests revealling that the results may be made inaccurate if the user does a few common, everyday things beforehand.
Create a free account to read this article
$0/
(min cost $0)
or signup to continue reading
On Wednesday the TGA updated its advice, saying saliva and oral fluid-based tests could return false results if the user was to eat, drink, chew gum, brush their teeth or smoke within a half hour window.
The medical regulator's fact sheet now says that "not using the test properly may produce an incorrect result".
Related:
It has also advised that the chances of producing a false result depend on the manufacturing differences across the different saliva and nasal swab test kits.
Only the saliva-based tests require the user to stop eating or drinking within a certain timeframe.
Orawell saliva kits, for example, will require the user to stop consuming food, drink, chewing gum or tobacco within 10 minutes of taking the test.
Whereas, the Ecotest kit requires the user to avoid all food, drink, chewing gum or tobacco for 30 minutes.
The TGA first approved at-home tests in November and there are currently six saliva test kits, and 17 nasal swab tests approved in Australia.
As the nation has switched over to greater reliance on the at-home tests this year, the head of the TGA Professor John Skerritt has defended the advice rollout timeline at this week's Senate committee hearing.
Professor Skerritt told the committee on Wednesday that it would have been "outright dangerous" to rollout the at-home tests before November with half of all results being "garbage".
"They were very aware of this problem that 50 per cent or more of our results would be garbage if we went into self-testing at a stage where we had very low disease prevalence and we're wanting to do individual contact and individual venue tracing," Professor Skerritt said.
He said it also would have interferred with the rigorous contact tracing methods that were being deployed across the country last year.
"You would have had people with false positives, and immediately you also would have missed a significant number of infections," Professor Skerritt said.