Transmission dynamic of respiratory multi-pathogen co-infection in a Chinese megacity: A modelling study based on Wuhan Big Data Center

To investigate the transmission dynamics of respiratory multi-pathogen co-infection, this study developed a dual-pathogen co-infection transmission dynamics model comprising 10 compartments, incorporating an exponentially decaying time-varying effective transmission rate. The model was systematically calibrated and validated using epidemiological surveillance data from a major Chinese metropolis—Wuhan—covering approximately 2.72 million cases between January 1, 2023 and January 1, 2025. The analysis focused on the 13 most common pathogen combinations, which accounted for the top 1% of infection cases. Results revealed three distinct winter-centered epidemic peaks in Wuhan over the two-year period. Co-infection cases were most frequently observed as virus–bacteria and virus–other pathogen combinations. Analysis of the major co-infection combinations showed that the mean basic reproduction number of the system ranged between 1.19 and 1.88, while the median ranged from 1.08 to 1.35. Transmission peaks in each combination were primarily driven by the most transmissible pathogen within the pair. Transmission route analysis further indicated that when individuals were infected with multiple pathogens, sequential secondary infection was the dominant pattern, whereas direct simultaneous co-infection occurred at a relatively low proportion. This study suggests that respiratory pathogens continue to exhibit sustained transmission potential. The findings provide an important evidence based reference for designing risk oriented, precision prevention and control strategies in the future.