A coronavirus disease 2019 outbreak in a residential living facility with suboptimal ventilation in resident rooms.

We report a large outbreak of severe acute respiratory syndrome coronavirus 2 in a residential living facility. Measurements of carbon dioxide levels, aerosol particle clearance, and airflow were used to identify and remediate areas with suboptimal ventilation. A simple intervention involving continuous operation of bathroom fans was effective in significantly improving ventilation in resident rooms. ● Areas with suboptimal ventilation pose a risk for SARS-CoV-2 transmission. ● An outbreak of COVID-19 occurred in a hospital-affiliated residential living facility. ● Carbon dioxide monitoring and aerosol clearance were used to assess ventilation. ● Testing demonstrated that double-occupancy resident rooms were poorly ventilated. ● Operation of bathroom fans significantly improved ventilation in resident rooms. [ABSTRACT FROM AUTHOR]