New study shows symptom screenings miss many cases of COVID-19

WASHINGTON — A new study finds temperature and COVID-19 symptom checks, like the ones used at schools and doctors' offices, are not enough for catching infections and preventing outbreaks.

Researchers recently looked at more than 1,800 Marine recruits.

They were all told to isolate for two weeks at home, then in a supervised military quarantine at The Citadel in Charleston, South Carolina, for two more weeks.

The recruits had daily fever and symptom checks and followed other restrictions like wearing masks.

Sixteen tested positive from the military quarantine and only one had any symptoms.

Another 35 recruits tested positive during the two-week quarantine. Four of them had symptoms.

None of the infections were caught through symptom screening.

Genetic testing revealed six separate clusters of cases among the recruits.

The research is published in the New England Journal of Medicine.