Epidemiological analysis of norovirus infectious diarrhea outbreaks in Chongqing, China, from 2011 to 2016

作者：Baisong Li, Dayong Xiao, Yanlin Li, Xianlan Wu, Qi Li, Wenge Tang, Qin Li · 发表于：Journal of Infection and Public Health · 年份：2019 · DOI：10.1016/j.jiph.2019.06.019 · 被引用次数：20 · 研究领域：Viral gastroenteritis research and epidemiology

OBJECTIVE: We investigated the epidemiological characteristics of norovirus infection from 2011 to 2016 in Chongqing, China, in order to provide evidence for strategies on epidemic prevention and control. METHODS: We collected data on norovirus infectious diarrhea epidemics in 38 districts and counties, and analyzed the information using descriptive epidemiological methods. RESULTS: In 2011, the first case of norovirus infectious diarrhea in Chongqing was reported. From 2011 to 2015, 38 districts and counties in Chongqing reported a total of 4 epidemics. In 2016, however, the city reported 117 outbreaks. From 2011 to 2016, there were 1637 cases of norovirus infection but no deaths. In 2016, most outbreaks occurred over a 5-month period with a clear peak in December and higher incidence in major urban areas than smaller communities (83.61% vs. 16.39%). Of these 1637 cases, 99.18% occurred in urban schools and nurseries, and 80% were transmitted person-to-person. Infection by genogroup II genotype 2 (GII.2) viruses accounted for 98.71% of cases. Leukocytes were increased in 67.81% of patients, neutrophils in 65%, and lymphocytes in 50%. Medical treatment was sought by 70% of patients or guardians but only 3.66% of cases were hospitalized. The most frequent misdiagnosis was "suspected food poisoning". CONCLUSION: The frequency of norovirus infectious diarrhea epidemics increased over 20-fold from 2011 to 2016 in Chongqing, China. These epidemics occurred predominantly in urban s...