Temporal distribution characteristics of Salmonella foodborne disease in China based on the circular distribution method

Objective: -associated foodborne disease cases in China from 2014 to 2024 were examined to estimate the peak time point and epidemic period and to inform seasonal prevention efforts. Methods: -positive foodborne disease cases reported to the National Foodborne Disease Active Surveillance System during 2014-2024 were extracted. Circular distribution analysis was used to assess seasonal concentration and estimate peak timing, and Rayleigh's Z test was used to evaluate seasonal clustering. Results: -associated foodborne disease showed clear seasonality, with a mean peak time point occurring on July 17 and a peak epidemic period spanning from May 17 to September 26. Conclusion: -associated foodborne disease in China shows a clear seasonal concentration, with a peak occurring in summer. These findings support prioritizing enhanced food safety supervision, targeted inspections of high-risk food settings, and strengthened public risk communication from May to September to reduce preventable exposures during the identified high-risk period.