济南市多起诺如病毒感染暴发疫情的流行特征

Epidemiological characters of several norovirus outbreaks in Jinan City

目的总结济南市近1年内发生的多起诺如病毒感染暴发疫情流行特征。方法收集济南市2015年6月1日至2016年5月31日期间发生的诺如病毒感染暴发疫情的时间分布特征、地区分布特征、实验室RT-PCR检测和基因测序结果、疫情报告和处置信息。结果 1年间,济南市共发生6起诺如病毒感染暴发疫情,疫情罹患率从0.41%到15.56%不等,3起发生于冬春季,4起发生于济南市历城区高校片区。3起疫情病例数超过250人,1起还超过了1 000人。GII感染疫情3起,GI和GII混合感染疫情3起,首次监测到诺如病毒感染新型别GI.1和GII.17。从疫情开始到报告、从介入调查到结束、疫情持续时间平均分别为2d、4d及6d。结论济南市诺如病毒感染暴发疫情在发生时间、发生场所、疫情规模以及诺如病毒感染型别已呈现出新的流行特征与趋势,尤其是应进一步加强学校重点场所的传染病监测和疫情报告能力,争取疫情早控制。

Objective The epidemiological features of several norovirus outbreaks in the past year in Jinan City were surveyed. Methods The information including： the features of time distribution, place distribution, laboratory results of norovirus RT - PCR test, gene sequencing analysis, epidemic report and information management was collected. Results A total of six norovirus outbreaks was reported in the past year with different attack rates （ AR） , from 0. 41% to 15. 56% in Jinan City. Among the six outbreaks, three occurred in Winter-Spring,four occurred in the university region of Licheng Distric, Jinan City. The case number exceeded 250 in 3 outbreaks,one of them even reached 1 000 cases. Laboratory results showed that three outbreaks were caused by Genogroup II （GII）, 3 outbreaks were caused by a mixed infection of Genogroup I （GI） and GII, two new genotypes, norovirus GI. land GII. 17 were identified for the first time in Jinan City. The average time of six outbreaks ： from the onset to reporting, from starting investigation to the end, and the epidemic lasting time was 2 days, 3 days and 6 days, respectively. Conclusion The outbreak of norovirus in Jinan City showed new epidemiological features and trend in the time of occurrence, place of occurrence, the scale of the epidemic and the type of viral infection. It is necessary to promote the surveillance and the reporting ability,especially in schools,to fight for the early control of the outbreak.