一起养老院急性胃肠炎疫情的病原学分析

目的明确一起养老院感染性腹泻疫情的病原体及其基因型别。方法通过流行病学调查,查明罹患率。对发病老人和部分工作人员进行肛拭子采样,采用细菌培养检测常规肠道致病菌,应用胶体金法检测轮状病毒,采用实时荧光定量RT-PCR进行诺如病毒核酸检测,应用常规RT-PCR扩增部分NoV阳性株衣壳蛋白的N/S区,PCR产物纯化回收、测序,利用Clustal X、MEGA4.1软件分析其基因序列。结果 21份病例及工作人员肛拭子样本,肠道致病菌和轮状病毒均为阴性,19份样本诺如病毒核酸阳性,毒株排除重组株的可能,测序样本均属GⅡ.4型诺如病毒,其与Hu/NSW696T/2006/AUS（EF684915）的同源性高达99%。结论经诺如病毒核酸序列分析,该疫情是一起由GⅡ.4-2006b型诺如病毒引起的急性胃肠炎暴发。

Pathogenic Analysis of Acute Gastroenteritis Outbreak in a Nursing Home

Objective To analyze the cause of acute gastroenteritis outbreak in a nursing institution of Shanghai. Methods Stool samples were collected to detect enteric pathogens and RV.NoVs were detected by real-time RT-PCR and conventional RT-PCR.The PCR products were purified and sequenced,and then compared the sequences of the PCR products in GenBank using on line server BLAST and the sequences were aligned by using Clustal W.MEGA 4.1 program was employed to construct the phylogenetic trees,and SimPlot3.5.1 program was employed to indentify the recombinant NoV strain. Results All the stool samples were negative to enteric pathogens and RV,19 of 21 stool samples were positive to NoV,which included 11 stool samples of the old patients and 8 stool samples of the staff.The NoV shared 99% nucleotide sequence identity with Hu/NSW696T/2006/AUS(EF684915). Conclusions By comparing the nucleotide sequence,this acute gastroenteritis outbreak was caused by GⅡ.4 norovirus strain,which may supply important information to study the norovirus in the elderly.