一起不明原因感染性腹泻疫情的病原学诊断

Pathogenic diagnosis of an unexplained epidemic event of infectious diarrhea

目的明确一起不明原因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的方法，查明罹患率。对28例疑似病例的28份样本（粪便22份，呕吐物3份，肛拭子3份）采用RT-PCR方法进行诺如病毒核酸检测，并对5份阳性标本的核酸进行序列测定及遗传进化分析。结果在调查的5694人中，发病160例，罹患率为2．81％。2007年3月7-913为发病高峰。RT-PCR检测28份样本中，确定14份为阳性。对其中的5株毒株的核酸序列测定及序列遗传进化分析确定为GⅡ／4型诺如病毒，并与2006年诺如病毒流行株2006b同源性最高，为97．9％。结论本次感染性腹泻疫情由诺如病毒引起。

Objective To determine the pathogen of an unexplained epidemic event of infectious diarrhea by laboratory diagnosis of suspected cases samples. Methods 28 samples from 28 suspected cases （22 fecal samples,3 vomitus samples, 3 anus swab samples） were tested for Norovirus by RT-PCR. Sequencing and phylogenetic analysis were aeomplished of 5 positive samples. Results 160 of 5694 population were ill with an attack rate of 2.81% . The peak period was 7-9, March. 14 of 28 samples were tested Norovirus positive. Sequencing and phylogenetic analysis showed Norovirus type G Ⅱ/4 was the causative agent and it had highest identity （97. 9 % ） with epidemic strain 2006b. Conclusion The epidemic event of infectious diarrhea were caused by G Ⅱ/4 Norovirus strains.