Assessing COVID-19 transmission risk: Roommate and unit mate exposures at an inpatient behavioral health facility.

Background: Inpatient psychiatric facilities have an increased risk of infection transmission. This study evaluated the impact of roommate and unit mate exposures on coronavirus disease-2019 (COVID-19) transmission to inform isolation practices.

Methods: A single-center retrospective study was conducted among patients hospitalized in an inpatient behavioral health hospital from July 2020 through August 2023. We compared the risk of COVID-19 acquisition after exposure among patients with a contagious roommate versus those exposed to a contagious unit mate.

Results: During the study period, the conversion rate was 10.05% overall, 24.4% for roommates, and 9.3% for unit mates; patients exposed to a roommate were at 3.14 times higher odds (95% confidence interval, 1.42-6.92) of acquiring COVID-19 after exposure. On unit-stratified analysis, patients exposed to a roommate on the geropsychiatric unit had the highest risk of postexposure conversion compared with unit mate exposed patients (odds ratio 6.38, 95% confidence interval 1.75-23.22). Logistic regression analysis identified a nonsignificant risk associated with increased time in group therapy.

Conclusions: Exposure to a COVID-19-contagious roommate significantly increases the risk of COVID-19 acquisition among exposed patients receiving inpatient psychiatric care. Cohorting contagious and exposed individuals and avoiding multibedded rooms may mitigate COVID-19 transmission risk during psychiatric care.