Abstract：Objective To explore the epidemiological characteristics of 15 outbreaks of norovirus infection reported by schools in Hunan Province in 2021, and to provide a scientific basis for formulating prevention and control strategies. Methods We collected the epidemic data regarding outbreaks of norovirus infection in schools reported in the Public Health Emergency Management Information System in Hunan Province from January 1 to December 31, 2021, and then analyzed by using descriptive epidemiological methods. Results Hunan Province reported 15 outbreaks of norovirus infection in schools in 2021, with 711 cases reported and the attack rate being 1.70%. The epidemic outbreaks mainly occurred in primary and middle schools (each n=5), followed by high schools (n=3). All the outbreaks occurred in winter and spring (March-April and December-January). The transmission route of the epidemic outbreaks was mainly human-to-human (n=10), and the epidemic outbreaks caused by water-borne transmission (n=4) and food transmission (n=1) were less. The duration of the epidemic outbreaks was significantly or extremely significantly positively correlated with the timeliness of the epidemic reporting (r=0.535, P<0.05) and the number of patients in a single outbreak (r=0.809, P<0.001). Statistically significant differences were observed between human-to-human transmission and water-borne transmission (χ2=128.32, P<0.001) as well as between human-to-human transmission and food-borne transmission (χ2=16.50, P<0.001), but no statistically significant difference was found between water-borne transmission and food-borne transmission (χ2=2.58, P>0.05). 8 of the 15 outbreaks were caused by GII norovirus, accounting for 53.33%. Conclusion The outbreaks of norovirus infection in Hunan Province in 2021 mainly occurred in primary and middle schools, and the transmission route was mostly human-to-human transmission.
2023, Vol. 30 
