An Epidemiologic Study of COVID-19 Patients in a State Psychiatric Hospital: High Penetrance With Early CDC Guidelines.

Objective: This study aimed to explore the transmission of COVID-19 in a U.S. state psychiatric hospital setting.

Methods: Symptomatic and asymptomatic patients were tested throughout a large psychiatric hospital to determine penetrance. The hospital followed initial Centers for Disease Control and Prevention (CDC) guidelines.

Results: Seventy-eight percent (N=51 of 65) of tested patients in the building where the first positive patient was housed (building zero) tested positive for COVID-19. Eighty-eight percent (N=14 of 16) of tested asymptomatic patients in building zero were positive, compared with 12% (N=6 of 51) of randomly selected asymptomatic patients in a sample from the rest of the hospital.

Conclusions: A high percentage of patients can become positive for COVID-19 despite following initial CDC guidelines. As such, use of masks by all patients in close-quarter settings prior to the first positive case appears warranted. Recent CDC guidelines align with this strategy.