The New York City metropolitan area of the USA emerged as an epicentre of the COVID-19 pandemic. A recent population study showed a prevalence of SARS-CoV-2 antibodies of 21% in New York City and 17% in Long Island.

In this study, researchers sought to determine the prevalence of antibodies among healthcare workers by widespread screening for SARS-CoV-2 exposure at a 364-bed hospital in Roslyn, N.Y. (a Long Island community near New York City), where personal protective equipment (PPE) use was based on Centres for Disease Control (CDC) guidelines.

During March and April 2020, symptomatic employees underwent nasopharyngeal testing for the virus, and all employees were offered antibody testing. Of 3,046 employees (mean age, 43), 56% underwent antibody testing, and 10% of those tested employees were positive for antibodies.

In this study, the rate of SARS-CoV-2 infection was substantially lower among healthcare workers than among the general public in Long Island. The authors conclude that, because hospital healthcare workers "are exposed to a much higher density of the virus," the results provide strong evidence for the effectiveness of PPE use according to CDC guidelines.