Universal masking to control healthcare-associated transmission of severe acute respiratory coronavirus virus 2 (SARS-CoV-2).

Objectives: To assess extent of a healthcare-associated outbreak of severe acute respiratory coronavirus virus 2 (SARS-CoV-2) and to evaluate the effectiveness of infection control measures, including universal masking.

Design: Outbreak investigation including 4 large-scale point-prevalence surveys.

Setting: Integrated VA healthcare system with 2 facilities and 330 beds.