Abstract / Summary
Abstract Background This study aims to investigate the epidemiological characteristics and changes in the trends of other infectious diarrhoeal diseases in Zhoushan from 2016 to 2025 to provide evidence for the optimization of disease prevention and control strategies. Methods The population distributions of cases of other infectious diarrhoeal diseases were acquired from the China National Infectious Disease Network Direct Reporting System (CNIDNDRS). A descriptive epidemiological framework was applied to characterize incidence, seasonality, and demographic distribution, while Joinpoint regression analysis was employed to detect significant inflection points in the secular trend, adjusting for the 2020 pandemic interference. Results: A total of 15,493 cases of other infectious diarrhoeal diseases were reported during the study period, with an average annual incidence rate of 132.78 per 100,000 population. No fatal cases were reported. Seasonal peaks occurred in winter (December–February) and summer (July–September). The male-to-female sex ratio was 1.24:1. The highest number of cases occurred in the 0ཞ4-year-old group (10,584 cases, 68.31%), predominantly among children living in household settings (9,282 cases, 59.91%). Aetiological agents were identified in 25.99% of the reported cases. Viruses and bacteria accounted for 96.35% and 3.65% of the confirmed pathogens, respectively. Rotavirus was the leading viral pathogen (3,067 cases, 79.05%), while Salmonella was the predominant bacterial pathogen (130 cases, 88.44%). A total of 23 clustered outbreaks were reported, mostly caused by norovirus (20 outbreaks, 86.96%), with all the clusters occurring in schools or childcare facilities. Joinpoint regression analysis revealed a three-phase trend in the overall incidence: an increase from 2016 to 2018 (APC = 17.54%, P = 0.01), followed by a decrease from 2018 to 2023 (APC=-12.50%, P < 0.001), and a rapid increase from 2023 to 2025 (APC = 32.19%, P < 0.001). Conclusions According to the results of Joinpoint regression, other infectious diarrhea cases in Zhoushan,China, exhibit obvious seasonal characteristics, and show an upward trend. To better prevent and control the situation, it is necessary that prevention and control efforts should prioritize outbreaks in schools and childcare settings, promote rotavirus vaccination, and increase laboratory diagnostic capacity in local medical institutions. The results established a critical evidence base for tailored enteric disease control in island and coastal populations globally.