While the COVID-19 pandemic is fading from headlines, many countries continue requiring visitors to show negative SARS-CoV-2 virus test results. As a result, home antigen tests have become a favorite for international travelers with widespread availability, ease of use, and rapid turnaround time.
To better understand these tests, a recent Original Investigation published on April 29, 2022, by the peer-review journal the JAMA Network found home antigen test’s sensitivity for SARS-CoV-2 was moderate compared with RT-PCR but high compared with viral culture.
This investigation’s findings suggest that antigen test performance may differ in vaccinated vs. unvaccinated individuals.
And between SARS-CoV-2 lineages.
In the prospective cohort study of 225 adults and children with RT-PCR–confirmed SARS-CoV-2 infection observed for 15 days, home antigen test sensitivity peaked four days after illness onset.
Sensitivity improved when a second antigen test was performed 1 to 2 days later, particularly early in the illness course.
More than 50% of those who performed antigen tests on day 6 of illness had positive test results, but by day 11, fewer than one-fifth had positive test results.
This sensitivity was within the 34% to 88% range reported in a Cochrane review of other rapid, point-of-care SARS-CoV-2 antigen tests.
But it was less than the 80% target set by the World Health Organization for point-of-care tests.
Furthermore, similar to other studies on antigen test performance, these researchers found that the antigen test sensitivity was higher among symptomatic persons and earlier during the illness course.
Antigen test positivity was lower before and on the day of illness onset.
This is notable as SARS-CoV-2 transmission often occurs before and during the first few days following symptom onset.
Additional home test research is posted at CoronavirusToday.com/Tests.
Note: The JAM study was edited for clarity and manually curated for mobile readership.
