Epidemiological and Clinical Characteristics, Transmissibility, and Associated Factors of HAdV in Wuhan, China (2023-2024): Insights from a Multi-Center Public Health Surveillance System

Background Human adenovirus is not a notifiable disease in China, making surveillance essential, especially as respiratory illnesses rise after COVID-19. This study explores its characteristics and the factors affecting its incidence. Methods From 2023 to 2024, we used a multi-center surveillance system in Wuhan to identify human adenovirus infections. We conducted descriptive analyses to examine characteristics, used mathematical models to estimate transmissibility, and applied generalized additive models to analyze associated factors. Two prediction models were used to forecast future epidemics. Results Here we show that 2.17% of 683,868 individuals were infections; 53.59% required hospitalization, and fewer than 1% were severe or fatal. Infections were more common in males (1.70%-3.69% vs. 1.60%-3.08%) and children ≤14 years (610.96 vs. <100.00 per 100,000), while hospitalized, severe illness and death occurred mainly in older adults (91.94% vs. <60.00% for hospitalized; 2.86% vs. <2.00% for severe; 1.23% vs. <0.05% for death). Seasonal peaks were observed in winter and spring, with common symptoms including fever and cough (>49.00%). The 0.35% developed acute hepatitis. The basic reproduction number ( ) was 0.91, with median real-time transmission () was 1.00. Higher incidences were associated with colder weather, stronger winds, higher air pollution (NO₂, O ₃ ), internet search activity, and population mobility. Forecasts suggest several infection waves beginning in mid-2024, peaking in early 2025. Conclusions Although the prevalence and transmissibility remain low, adenovirus can cause serious outcomes in the elderly. Ongoing surveillance and vaccine development before and during the epidemic seasons are essential to reduce future impact.