(Reuters) – The rapidly spreading Omicron variant has made us more dependent on rapid at-home antigen tests to tell if we have COVID-19. But should we wipe our nose as well as our throat?
For now, guidance depends on where you live.
Some scientists have theorized that people can transmit omicron when it has infected their throat and saliva, but before the virus reaches their nose, so swabbing the nostrils early at the start of the infection can prevent it. will not fix.
A small recent US study supports that view. PCR tests of saliva from 29 people infected with Omicron detected the virus on average three days before nasal samples turned positive in antigen, or so-called lateral flow, tests.
In general, rapid tests have a lower sensitivity than laboratory-processed PCR tests, which means they produce more false negatives. But if you test positive, you almost certainly have COVID-19, which makes antigen tests a powerful tool for tackling the pandemic, due to Omicron’s labs in demand for PCR tests.
As a result of recent studies, some experts in the United States now recommend that antigen test users should swab the throat before swabbing the nose.
All antigen tests use nasal samples, with the US Food and Drug Administration’s emergency use authorizations expressing concerns over the safety of at-home sore throats, saying users should follow manufacturers’ instructions.
In Israel, a top health official has said that people self-testing for COVID-19 should swab their throat as well as their nose when using rapid antigen tests, even though This should be against the instructions issued by the manufacturer.
Some other countries, including the United Kingdom, have approved rapid antigen tests that swab both the throat and nose, or just the nose.
In Germany, the health minister has said they will study how reliable rapid antigen tests are at detecting the Omicron variant and will publish a list of the most accurate products.
(Editing by David Clarke)