Evaluation of UR-UVGI System for Sterilization Effect on Microorganism Contamination in Negative Pressure Isolation Ward

Jong-Il Bang,Jeongyeon Park,Jae-Weon Jeong,Anseop Choi,Minki Sung,Jin Kim

doi:10.3390/su10093192

Abstract

A negative pressure isolation ward prevents the outflow of airborne microorganisms from inside the ward, minimizing the spread of airborne contamination causing respiratory infection. In response to recent outbreaks of severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS), Korea has increased the number of these facilities. However, airborne contaminants that flow into the ward from adjacent areas may cause secondary harm to patients. In this study, the sterilization effect of upper-room ultraviolet germicidal irradiation (UR-UVGI) on microorganisms generated within the negative pressure isolation ward and those flowing inward from adjacent areas was evaluated through field experiments and computational fluid dynamics (CFD) analysis, to assess the potential of this approach as a supplementary measure to control such microorganisms. The sterilization effect was found to be not high because of high-level ventilation. CFD analysis under various conditions shows that the sterilization effect for indoor-generated microorganisms varies with the level of UV radiation, the source locations of the indoor-generated microorganisms, air supplies and exhausts, the UVGI system, and the airflow formed under the specified conditions. Our results show that when the UVGI system is installed in the upper part of the ward entrance, contaminated air from adjacent area is strongly sterilized.

Highlights

Negative pressure isolation wards have mostly been used to isolate patients with airborne infectious diseases such as tuberculosis and measles. During both the severe acute respiratory syndrome (SARS) outbreak, which began in Hong Kong in 2003, and the Middle East respiratory syndrome (MERS) outbreak, which led to mass infection in Korea in 2015, negative pressure isolation wards provided important quarantine facilities for the treatment of patients in the early stages of infection or confirmation of infection in other patients [1]
This study investigates the sterilization effects of a upper-room ultraviolet germicidal irradiation (UR-ultraviolet germicidal irradiation (UVGI)) system installed in the upper room area as a means of infection control for airborne microorganisms, which may be generated within negative pressure isolation wards and flow in from adjacent areas
This is assumed to be a result of the inflow of airborne microorganisms into the ward from the corridor and adjacent areas, as there were almost no sources of contaminants within the ward or airborne microorganisms in the air supplied from the high-efficiency particulate air (HEPA) filters

Summary

Introduction

Negative pressure isolation wards have mostly been used to isolate patients with airborne infectious diseases such as tuberculosis and measles. During both the severe acute respiratory syndrome (SARS) outbreak, which began in Hong Kong in 2003, and the Middle East respiratory syndrome (MERS) outbreak, which led to mass infection in Korea in 2015, negative pressure isolation wards provided important quarantine facilities for the treatment of patients in the early stages of infection or confirmation of infection in other patients [1]. After the SARS outbreak, the dire need for expansion of negative pressure isolation wards was recognized in Hong Kong, and hospitals specializing in infectious diseases that have more than 100 negative pressure isolation wards, such as Princess Margaret Hospital, were established. Since the MERS outbreak, the Korean government has once again recognized the need for such wards and has made government budget allocations to secure additional negative pressure isolation wards and to fund hospitals specializing in infectious diseases [1]

Methods

Results

Conclusion