Objective  To understand the epidemiological and etiological characteristics of intestinal infection cases in outpatients in Fangshan district of Beijing from 2016 to 2024, and provide evidence for the prevention and control of diarrhea.

Methods The case information was obtained through the Early Warning and Surveillance Network for Intestinal Infection in Beijing. Viral and bacterial pathogen detection results were obtained through etiological surveillance. Analyses were conducted by methods such as circular distribution, spatial autocorrelation and multivariate auto regressive moving average model analyses.

Results The average annual incidence rate of intestinal infection was 384.30/100 000 in Fangshan from 2016 to 2024. The incidence rate showed a fluctuating downward trend from 2016 to 2019 and remained at relatively low level from 2020 to 2024. The annual incidence peak during summer from July to August and sub-peak in December were observed from 2016 to 2018. The circular distribution analysis revealed that the incidence was high from April 12 to October 13, with the peak on July 12. The male-to-female ratio of the cases was 1.16∶1. The age of the cases ranged from 0 year to 101 years, with a median age of 34 years. The case count was highest in age group 30−<35 years, followed by age groups 25−<30 years and 0−<5 years. The case counts and incidence rates showed downward trends in all the townships and streets. Chengguan street had the highest case count and incidence rate. Except 2016, the positive spatial correlations in case count and incidence rate were observed in all the years. Norovirus GII had the highest detection rate (11.63%). In the bacterial pathogen detection, Campylobacter had the highest detection rate (9.00%). After including pathogen surveillance as an exogenous variable, the fitting of auto regressive moving average model model was improved.

Conclusion The detection of intestinal infection in Fangshan remained at a relatively low level in recent years. The annual incidence peaked during July - August, indicating that summer is a critical period for diarrhea prevention and control. Population aged 25−<35 years and <5 years are at higher risk for diarrhea. Measures should be taken in areas with higher case counts or incidence rates to reduce the disease burden of diarrhea. Norovirus is the main pathogen causing sporadic diarrhea cases, suggesting that strengthened surveillance and control efforts are needed.