牡蛎养殖区人群诺如病毒感染监测对暴发的预警作用

Norovirus infection surveillance in early warning of outbreaks in population in oyster farming areas

目的了解牡蛎养殖区人群诺如病毒感染病例的流行特征,研究病例监测对暴发的预警作用。方法 2014年1—12月,采用多阶段抽样方法从牡蛎养殖区选取部分社区人群进行入户调查,回顾其过去4周内急性胃肠炎的发病情况。采用实时RT-PCR与半巢式PCR相结合的方法检测诺如病毒,测序并绘制系统发育树。结果调查共发现75例急性胃肠炎病例,年发病率为0.10次/人年;诺如病毒阳性率为20.0%(15/75);系统发育分析显示,诺如病毒优势流行株为GII.4 Sydney 2012;发现新型GII.17变异株,检出时间为2014年3月。结论 GII.4 Sydney 2012仍是引起当地诺如病毒感染急性胃肠炎的主要流行株,在牡蛎养殖区哨点医院诺如病毒感染病例监测中发现的GII.17变异株对2014年冬季的暴发流行具有早期预警作用。

Objective To have an insight into the prevalence tendency caused by Noroviruses （NoVs） in population of oyster farming areas, and evaluate the early warning signification of acute gastroenteritis（AGE） monitoring. Methods Between January and December in 2014, a retrospective household survey of AGE during past four weeks was conducted to residents using multi-stage sampling in oyster farming areas. Norovirus capsid genome was detected using real-time RT-PCR and semi-nested PCR, sequenced and phylogenetie analyzed. Results A total of 75 cases of AGE were reported. The incidence rate was 0. 10 per person-year, the detection rate of norovirus was 20.0% （ 15/ 75）. The dominant epidemic NoVs strain in oyster farming was still GII. 4 Sydney 2012. Furthermore, a newly GII. 17 variant was detected and early in March 2014. Conclusion The GII. 4 Sydney 2012 genotype is still prevalent strain that caused AGE currently in the community residents of oyster farming areas. NoVs GII. 17 variant was found in sporadic patients of sentinel hospital AGE monitoring in March 2014 that have an early warning effect to the outbreaks of winter in 2014.