Are saliva tests the way forward? Some seem to think so...15 Jan 2022 06:19
https://www.nytimes.com/2022/01/14/health/saliva-testing-coronavirus-omicron.html
Article highlights;
“The virus shows up first in your mouth and throat,” Dr. Milton said. “That means that the approach we’re taking to testing has problems.”
Collecting samples of saliva, or swabbing the inside of the mouth, could help identify people who are infected with the virus days earlier than nasal swabs do, some research suggests.
“There’s been a growing body of evidence that at the very least, saliva performs well — it’s as good as, if not better, when it’s collected properly, when it’s processed properly,” Dr. Wyllie said.
Evidence also emerged that the virus tended to appear in saliva before it built up in the nose, suggesting that saliva samples might be the best way to detect infections early.
Dr. Milton and his colleagues recently found that in the three days before symptoms appear and the two days after, saliva samples contained about three times as much virus as nasal samples and were 12 times as likely to produce a positive P.C.R. result.
Saliva’s advantages may be more pronounced with Omicron, which appears to replicate more quickly in the upper respiratory tract and have a shorter incubation period than earlier variants.
Some experts have also theorized that Omicron may be better at replicating in the cells of the mouth and throat than other variants have been.
A team of South African researchers recently found that while nasal swabs performed better than saliva swabs when detecting the Delta variant, the opposite was true for Omicron.
In Britain, some at-home tests require swabbing both the throat and the nose, an approach that may be worth pursuing, experts said.