Abstract
BACKGROUND: Respiratory syncytial virus (RSV) is a common respiratory virus that causes respiratory diseases in all ages and causes severe diseases mainly among children and older adults. Understanding the seasonal pattern of RSV and its influencing factors is crucial for policy makers to optimize the timing of RSV immunization strategies. We explored the RSV seasonality and its associations with meteorological factors in Hong Kong from 2014 to 2023. METHODS: We collected weekly RSV surveillance data in Hong Kong between 2014 and 2023 from Centre for Health Protection (CHP) of Hong Kong. Three different approaches were applied to explore the RSV seasonality including the 50th percentile method, the average annual percentage (AAP) method, and the 2 % threshold method. A generalized additive model was used to explore the associations between RSV positive rate and meteorological factors. RESULTS: During 10-year study period, 44,722 specimens were positive for RSV with a positive rate of 2.81 % in Hong Kong. The RSV epidemic varied year-on-year, with annual and biannual epidemics observed. The three approaches identified similar RSV epidemic in Hong Kong, a total of 9 RSV epidemics were found. The RSV epidemics mainly occurred from mid-February to late September, with an average duration of approximately 6 months during the study years. We found that mean temperature was positively associated with RSV positive rate, while mean dew point temperature showed a negative association. CONCLUSIONS: RSV epidemic varied year-on-year in Hong Kong, the 2 % threshold is recommended as an alert threshold for RSV epidemics. A One Health perspective might enhance future prevention strategies by incorporating broader environmental and intersectoral factors.