Architectural interventions to mitigate the spread of SARS-CoV-2 in emergency departments

Abstract

Emergency departments (EDs) are a critical entry gate for infectious agents into hospitals. In this interdisciplinary study, we explore how infection prevention and control (IPC) architectural interventions mitigate the spread of emerging respiratory pathogens using the example of SARS-CoV-2 in a prototypical ED. Using an agent-based approach, we integrate data on patients' and healthcare workers' (HCWs) routines and the architectural characteristics of key ED areas. We estimate the number of transmissions in the ED by modelling the interactions between and among patients and HCWs. Architectural interventions are guided towards the gradual separation of pathogen carriers, compliance with a minimum interpersonal distance, and deconcentrating airborne pathogens (higher air exchange rates (AERs)). Interventions are epidemiologically evaluated for their mitigation effects on diverse endpoints. Simulation results indicate that higher AERs in the ED (compared to baseline) may provide a moderate level of infection mitigation (incidence rate ratio (IRR) of 0.95 (95% CI 0.93 - 0.98)) while the overall burden decreases more when separating rooms in examination areas (IRR of 0.78 (95% CI 0.76 - 0.81)) or when increasing the size of the ED base (IRR of 0.79 (95% CI 0.78 - 0.81)). The reduction in SARS-CoV-2-associated nosocomial transmissions is largest when combining architectural interventions (IRR of 0.61 (95% CI 0.59 - 0.63)). These modelling results highlight the importance of IPC architectural interventions; they can be devised independently of profound knowledge of an emerging pathogen, focusing on technical, constructive, and functional components. These results may inform public health decision-makers and hospital architects on how IPC architectural interventions can be optimally used in healthcare premises.