Monitoring for airborne respiratory viruses in a general pediatric ward in Singapore

Yadana, Su; Coleman, Kristen Kelli; Nguyen, Tham Thi; Hansen-Estruch, Christophe; Kalimuddin, Shirin; Thoon, Koh Cheng; Low, Jenny Guek Hong; Gray, Gregory Charles

In addition to bioaerosol sample collection and handling methods, environmental conditions can also influence the viability of airborne viruses and downstream virus recovery. For example, prolonged sampling periods can compromise stability of virus-laden aerosols and result in decreased viral recovery. 12 Additionally, it has been demonstrated that the survival of airborne influenza virus depends on ambient temperature, relative humidity (RH) and ultraviolet radiation levels. 13 Specifically, infectivity of influenza in a simulated examination room was reported to be the highest at 7-23% RH, moderate at 57% RH and lowest at 43% RH. 14 Although we did not record temperature and RH at our sampling site, a previous bioaerosol study recorded levels ranging from 54% to 68% RH in three different hospitals in Singapore. 11 High RH levels in Singapore could explain the low percentage of influenza A viruspositive aerosol samples in our study.