Onsite measurement and dilution-based infection risk assessment for a new mobile negative pressure isolation room (MNPIR) as a solution to minimize cross-infection

Abstract

This study proposes an onsite measurement protocol and infection risk assessment using tracer gas tests based on the dilution-based method to evaluate the ventilation system's performance in the mobile negative pressure isolation room (MNPIR) and minimize infection risk for health care workers (HCW). The dilution-based infection risk assessment is better in determining spatial distribution of infection risk compared to the Wells-Riley model. The study shows that ventilation effectiveness to reduce the infection risk for HCWs can be reviewed using four onsite measurement protocols and a dilution-based infection risk assessment. Optimizing the SA and EA installation locations is key to reducing the cross-infection risk of HCWs, and the contaminant removal effectiveness (CRE) index averaged 2.6, indicating adequate ventilation efficiency. By applying an appropriate ventilation system, the infection risk in HCW spaces was reduced to 50% or less of the average risk (by the Wells-Riley model). The proposed approach allows for quantitative evaluation of infection risk by location and exposure time, demonstrating that the MNPIR can effectively minimize infection risk for HCWs. The study suggests follow-up research on cooling and heating strategies that consider both patient comfort and effective ventilation performance in the MNPIR.