Preparing for the next pandemic : minimizing airborne transmission in general inpatient wards through management practices

Abstract

Existing infection control studies in hospitals focused on rooms with special ventilation requirements. Study on proper management practices and ventilation strategies in general inpatient wards are critical but currently lacking. To identify the simple operational practices that can limit airborne transmission within a general inpatient ward with the patient cubicle, nursing station and corridor, this study investigates the effects of infected patient locations, air change rates (ACH) and door opening angles on bioaerosol dispersion using a novel tracer gas sensor network. Experimental results show that the supply inlet and infected patient locations significantly affects the distribution and dispersion of the tracer gas within the ward. Using a higher ventilation rate to achieve a lower average airborne pathogen concentration can cause more mixing of air and a wider dispersion of airborne pathogens. Localization of bioaerosols near the source through ventilation controls, a low ACH and proper patient location near the exhaust can minimize the air turbulence and the spread and reduce the infection risks of the susceptibles. Using physical partitions or objects as shields against airborne contaminants can unpredictably influence the airflow patterns, airflow evaluations should hence be done on a case-by-case basis. The methodology established in this study puts forward an economical and fast way for evaluating airborne infection risk, and the experimental results can be useful references for building engineers and hospital facility managers to formulate proper strategies for risk assessment and infection control.