Headshot of Wesley H. Self, M.D.

A study spanning major medical institutions has found that a high proportion of coronavirus infections among healthcare workers may go undetected, reports the Centers for Disease Control and Prevention.

Investigators analyzed COVID test data from more than 3,200 providers in 13 U.S. medical centers who regularly cared for COVID-19 patients, beginning Feb. 1. Fully 6% of the providers had antibody evidence of a previous infection. In addition, 29% of those with antibodies self-reported no previous symptoms, and 69% said they had never received a diagnosis of SARS-CoV-2 infection, wrote study lead Wesley H. Self, M.D., of the Vanderbilt University School of Medicine.

“These findings suggest that some SARS-CoV-2 infections among frontline healthcare personnel are undetected and unrecognized,” Self and colleagues wrote. This may be due to lack of symptoms, underreporting of symptoms and inconsistent testing of personnel with symptoms, the researchers concluded.

Notably, workers who reported that they always wore a face covering while caring for patients had a lower prevalence of antibodies (6%), compared with those who did not (9%). Universal use of face coverings and lowering clinical testing thresholds could be crucial strategies for reducing transmission in these settings, the researchers said.

The study was published Monday as an early release in the CDC’s Morbidity and Mortality Weekly Report.

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