Objective To analyze the epidemiological characteristics of clustered vomiting and diarrhea outbreaks in Minhang District of Shanghai, to identify the influencing factors of outbreak scale and duration of epidemic, and to provide scientific evidence for further strengthening surveillance early-warning efforts in key settings and for optimizing prevention and control measures.

Methods The data for describing epidemiological characteristics of clustered vomitting and diarrhea outbreaks in Minhang District from 2018 to 2023 were collected, multivariable logistic regression models were applied to analyze the influencing factors for epidemic scale,and Spearman rank correlation analyses were applied to analyze the factors duration.

Results A total of 136 clustered vomiting and diarrhea outbreaks were reported in Minhang District from 2018 to 2023, all occurring in school settings, with an overall attack rate of 0.90%. The outbreaks exhibited distinct seasonality, predominantly occurring from October to December (43.38%) and March to May (32.35%). The primary settings were preschools (45.59%) and elementary schools (44.12%), with students accounted for the majority of cases (99.48%). The predominant clinical manifestation was vomiting (90.44%), with person-to-person contact being the primary transmission route (98.53%). Norovirus genogroup Ⅱ was identified as the main pathogen (71.32%). Standardized terminal disinfection of outbreak sites (OR=0.39, 95%CI=0.20‒0.74) and effective isolation of affected classes (OR=0.23, 95%CI=0.09‒0.57) were significant protective factors for reducing outbreak scale. Both response time (r=0.64, P<0.001) and the number of case generations (r=0.71, P<0.001) showed positive correlations with outbreak duration.

Conclusion Schools are the key settings for the prevention and control of clustered vomiting and diarrhea outbreaks in Minhang District, with peak occurring in autumn and spring. Early detection, timely reporting, and prompt response to outbreaks are crucial. Strengthening school-based surveillance systems and standardizing outbreak management protocols are of particular importance.