A Comparison of Viral Aerosols in Indoor Spaces of Higher Education: Flu Season vs. Non-Flu Season

JING LI, Yifang Zhu, University of California, Los Angeles

     Abstract Number: 277
     Working Group: Aerosol Science of Infectious Diseases: Lessons and Open Questions on Models, Transmission and Mitigation

Abstract
During the last fall and winter, the US experienced a surge in respiratory infections, with children being infected with the Respiratory Syncytial Virus (RSV), flu cases increasing, and COVID-19 continuing to circulate. The transmission of viral aerosols indoors continues to pose a severe respiratory infectious disease burden to the public. However, there is limited knowledge regarding the distribution patterns of these respiratory particles in common enclosed spaces such as classrooms and conference rooms. Here in this study, we collected 12 air purifier filters from 8 classrooms and 7 air purifier filters from 6 conference rooms at the Center for the Health Sciences (CHS) Building at the University of California, Los Angeles. All air purifiers from Blueair used HEPASilent™ technology, which captures 99.97% of particles as small as 0.1 μm. The filters were installed in early September 2022 before the fall quarter began and collected at the end of March 2023 after the winter quarter ended, overlapping with the flu season and the “tripledemic” of COVID-19, influenza, and RSV infections. Brand new Blueair filters were installed at the time of collection and will be collected again in mid-June 2023 after the spring quarter ends. We will extract and analyze the viral RNA of SARS-CoV-2, influenza viruses, and RSV attached to the dust particles on the air purifier filters. The research will investigate the distribution of these respiratory viruses during flu season and non-flu season and the difference between classrooms and conference rooms. Furthermore, the study will also examine the association between class size and viral aerosol concentrations. The study findings will be valuable in assessing the risk of different airborne respiratory viruses and developing better practices to mitigate exposure to airborne viruses. Ultimately, this will aid in preventing the transmission of respiratory infectious diseases in classrooms and other indoor environments.