Airborne Influenza Virus Monitoring in an Elementary School Using the Growth-based Virus Aerosol Concentrator with Paper-based Sensors

CHANHWI PARK, Junbeom Jang, Jaesung Jang, Ulsan National Institute of Science and Technology, Korea

     Abstract Number: 44
     Working Group: Bioaerosols

Abstract
Monitoring of viruses in indoor air is crucial for preventing the spread of respiratory diseases. In particular, influenza viruses exhibit a high infection rate among children, and the communal living environment in schools serves as a significant risk factor for group transmission. However, technology for rapid monitoring of airborne viruses faces several challenges, and researches on airborne viruses within elementary schools is currently very limited.

In this study, we present an airborne influenza virus monitoring system that integrates the water condensation growth-based virus aerosol concentrator (GVC) with paper-based immunosensors for on-site airborne influenza virus surveillance. In a laboratory, the GVC concentrated airborne viruses to detectable levels (more than 350 copies/mL) within 10 min at 6 Liters/min (LPM), and the concentrated viruses could be measured within 30 min using paper-based sensors. These paper-based sensors were designed to measure two viral proteins, surface protein hemagglutinin (HA) and internal protein nucleoprotein (NP), enabling the assessment of the degree of surface damage to virus particles. The limit of detection (LOD) of the sensors were 42 PFU/mL for HA and 62 PFU/mL for NP within a range of 10¹ to 10⁶ PFU/mL. Furthermore, we conducted air sampling and sensor measurements for various locations within an elementary school near UNIST, including classrooms, cafeteria, and corridors, using the measurement system over 8 working days, collecting a total of 17 samples at a flow rate of 6 LPM for one hour each. The results confirmed influenza-positive in five samples with concentrations ranging from 10¹ to 10⁵ PFU/mL. These results were compared with those obtained using the commonly used SKC BioSampler and gelatin filters, demonstrating that the currently proposed system has the strong potential for real-time, on-site, and continuous indoor airborne pathogen monitoring in various fields.