调查2020年苏州市相城区某社区一起由诺如病毒引起的聚集性感染事件，查找病因和传播危险因素，为新型冠状病毒疫情期间社区胃肠道传染病防控提供科学依据。

制订病例定义并进行流行病学调查，运用描述性和分析性统计方法分析聚集性感染事件流行病学特征和危险因素，采集病例咽、肛拭子和井水标本，进行可疑病原体PCR核酸和致病菌检测。

本次感染事件共发现病例15人，其中患者≥10岁组罹患率为23.08%（6/26），＜10岁组罹患率为81.82%（9/11），两组差异有统计学意义［Fisher's法（双侧）P=0.002］。病例对照研究显示：门口玩耍暴露差异有统计学意义［Fisher's法（双侧）P=0.006，OR值=11.43，95%CI：1.94~67.26］，是本次胃肠炎的暴露危险因素。

本次聚集性感染是由GⅠ型诺如病毒引起，传播途径是儿童一起玩耍，相互接触传染，发病后又引起家庭内部传播。

To conduct an epidemiological survey of a clustering infection of norovirus infection in a community of Xiangcheng District of Suzhou, to find out the causes and risk factors of spread, so as to provide a scientific basis for the prevention and control of gastrointestinal infectious diseases in the community during the COVID-19 epidemic.

Case definitions were developed, epidemiological characteristics and risk factors of the infection were decrypted and analyzed. Throat and anal swabs and well water samples were collected for PCR analysis and pathogen identification.

There were 15 infected patients in the community. The attack rate was 23.08% (6/26) in the group ≥10 years old and 81.82% (9/11) in the group ＜10 years old, there was a significant difference between the two groups [Fisher's exact test (2-sided) P=0.002]. The case-control study showed that the difference of exposure (playing outdoors) was statistically significant [Fisher's exact test (2-sided) P=0.006, OR =11.43, 95% CI: 1.94-67.26], which was the risk factor for spread.

The incidence of acute gastroenteritis is caused by norovirus GI. It is transmitted by children playing together and passing onto each other.