Workroom contact networks: implications for COVID-19 and other respiratory infections

OBJECTIVE: To examine how physician workroom size affects healthcare professional contact networks and the risk of respiratory virus transmission. DESIGN: Prospective observational study with agent-based simulations. SETTING: Two physician workrooms of differing size (internal medicine, 208.7 sq ft; cardiology, 112.6 sq ft) in a large academic hospital. METHODS: We deployed wireless sensor networks over 18 days in internal medicine and 14 days in cardiology workrooms. Physicians, residents, and medical students wore proximity-sensing badges during work shifts. Contacts were defined as two healthcare professionals within six feet, based on calibrated received signal strength indicators. Contact networks were generated in one-minute intervals. We simulated respiratory disease spread using a Susceptible-Infected (SI) model across varying transmission probabilities and estimated infection risk at different room densities. RESULTS: Average occupancy was 2.7 persons in internal medicine and 2.3 in cardiology. Despite lower occupancy, the smaller cardiology room exhibited greater contact density: healthcare professionals in the smaller room had higher mean and median numbers of contacts. SI simulations showed consistently higher risk of secondary infections in the cardiology room, even at lower transmission probabilities. CONCLUSIONS: Workroom size significantly affects healthcare professional contact density and infection risk. Smaller rooms increased opportunities for transmission despite lower average occupancy. Designing larger workrooms, limiting occupancy, or reconfiguring shared spaces may reduce infection transmission in healthcare facilities.