Influence of meteorological factors on the incidence of varicella in Chongqing, 2010-2019.

Varicella is a highly contagious disease that represents an escalating public health concern. This study aimed to assess the influence of meteorological factors on varicella incidence, identify vulnerable populations, and estimate the disease burden associated with meteorological exposure. Data were collected from Chongqing Municipality (2010-2019), including varicella case counts and seven meteorological variables. We employed a method combining a quasi-Poisson generalized additive model with a distributed lag nonlinear model and adjusting for potential confounders. A total of 183,692 varicella cases were reported. The analysis revealed that meteorological factors exhibited nonlinear relationships with varicella incidence. Notably, the strongest cumulative effects were observed for mean temperature (14.0 °C, RR = 1.246, 95% CI: 1.157-1.340), diurnal temperature range (0.6 °C, RR = 1.249, 95% CI: 0.993-1.571), relative humidity (97%, RR = 1.995, 95% CI: 1.639-2.429), aggregate rainfall (119.5 mm, RR = 5.062, 95% CI: 1.001-25.593), and mean air pressure (991.4 hPa, RR = 1.438, 95% CI: 1.331-1.554). Sunshine hours ≥ 5.6 h and wind speeds ≥ 2.1 m/s were protective. Adolescents aged 12 to 18 years exhibited the highest prevalence during periods of moderate temperature, high rainfall, and high humidity. Furthermore, the attributable risk analysis confirmed that meteorological factors significantly contribute to the varicella burden. These findings underscore the importance of incorporating meteorological patterns into public health strategies, including early warning systems and meteorologically specific interventions, to mitigate varicella transmission risk, particularly in the context of climate change.