Discerning the seasonal variations in respiratory virus exposure across networked populations through participatory surveillance

Abstract During the COVID-19 epidemic, community settings giving rise to recurrent outbreaks had been targeted for interventions, providing insights into controlling other respiratory infection outbreaks. Grounded on a territory-wide participatory surveillance cohort in Hong Kong, this study uncovered the seasonal hotspots of respiratory infection and associated patterns of virus exposure. In total, 57,921 monthly digital survey entries were collected from 2601 participants between March 2023 and February 2025. Attendance to workplace, hotel vacation and worship was consistently associated with influenza-like illness (ILI) reports during both peak and off-peak seasons. During peak seasons, ILI was more prevalent among healthcare workers and people living in households with children, in contrast to socially active individuals otherwise. As elucidated in network models, the working population was demonstrated to form the hub of infections, given their interactions with various community members. Epidemiological patterns derived from participatory surveillance could inform setting-based strategies for pre-empting respiratory infection outbreaks.