一起诺如病毒所致急性胃肠炎的病原学调查

Etiological survey of acute gastroenteritis caused by Norovirus

目的确定天津市一起水源性急性胃肠炎暴发的致病原。方法采集病例粪便标本,饮用深井水标本,采用荧光定量(Real-time PCR)检测病毒核酸,包括轮状病毒、杯状病毒、星状病毒和肠道腺病毒,阳性标本进行逆转录-聚合酶链反应(RT-PCR)扩增及测序分析。对粪便标本进行常见肠道致病菌的检测。结果采集粪便标本33份,检出诺如病毒GⅠ型阳性5份(15.2%),诺如病毒GⅡ型阳性12份(36.4%),诺如病毒GⅠ型、GⅡ型均阳性3份(9.1%)。经测序分析1株GⅠ型为GⅠ/14基因型;4株GⅡ型中,2株为GⅡ/8型,1株为GⅡ/6型,1株为GⅡ/2基因型。轮状病毒(A,B,C组)、札如病毒、星状病毒、肠道腺病毒和肠道致病菌检测均为阴性。3份饮水标本中轮状病毒(A,B,C组)、诺如病毒(GⅠ型,GⅡ型)、札如病毒、星状病毒、肠道腺病毒检测均为阴性,常见肠道致病菌检测结果均为阴性。结论本次水源性急性胃肠炎暴发系由诺如病毒GⅠ型/Ⅱ型混合感染引起。

Objective To investigate the main pathogens of acute gastroenteritis outbreak in Tianjin. Methods Stool and well water samples were collected to detect viruses by real-time PCR and RT-PCR. Viruses detection included rotavirus （A, B, C group）, Norovirus （G Ⅰ, G Ⅱ ）, sapovirus, adenoviruses and astrovirus. The enterupathogenic becteria were detected in feces at the same time. Sequence analysis was conducted on the positive samples. Results A total of 33 feces specimens were collected from acute gastroenteritis cases. Norovirus G Ⅰ was present in 15.2 %, GⅡin 36.4 %, both G Ⅰ and G Ⅱ were present in 9.1%. The sequences of the viruses detected from the stool samples of the patients belonged to the norovirus G Ⅰ and GⅡ .One strain of G Ⅰbelonged to G Ⅰ/14. Among four strains of G Ⅱ ,two belonged to G Ⅱ/8, one belonged to G Ⅱ/6, one belonged to G Ⅱ/2. No rotavirus （A, B, C group）, sapovirus, adenoviruses, astrovirus and enteropathogenic becteria were detected. Three well water samples were acute gastruenteritis viruses-negtive. Conclusion This gastroenteritis outbreak was caused by norovirus G Ⅰand G Ⅱ.