CDC: Comparison of COVID-19 home antigen test with RT-PCR, viral culture

Editor's Note

This study, led by researchers from the Centers for Disease Control and Prevention (CDC), finds that symptomatic individuals with an initial negative home antigen test should test again 1 to 2 days later because test sensitivity peaks several days after COVID-19 onset.

In 225 adults and children with confirmed COVID-19 infection, antigen test sensitivity was 64% compared with same-day RT-PCR testing and 84% compared with same-day viral cultures.

Antigen test sensitivity peaked 4 days after illness onset at 77%, and sensitivity improved with a second test 1 to 2 days later at 81% to 85%. Six days after illness onset, antigen test positivity was 61%.

The results suggest that sensitivity of home antigen tests for COVID-19 was moderate compared with RT-PCR and high compared with viral cultures. The results also suggest that antigen test sensitivity peaked several days after illness onset and improved with repeated testing, the researchers say.