无锡地区2013年腹泻人群诺如病毒分子流行病学特征分析

Analysis of molecular epidemiological characteristics of norovirus in diarrhea group in Wuxi in 2013

目的了解无锡市诺如病毒流行特征及主要流行株的基因型。方法采集2013年无锡市哨点医院监测的409份急性腹泻者的粪便标本和9起诺如病毒暴发疫情的病例标本,采用实时荧光定量PCR检测诺如病毒GⅠ和GⅡ基因,对GⅡ基因阳性标本进一步进行扩增及测序分型。结果哨点监测病例诺如病毒阳性率为9.78%(40/409)。所测36株诺如病毒共有5种基因型,依次为GⅡ.Pe/GⅡ.4型28株(77.78%)、GⅡ.P12/GⅡ.3型4株(11.11%)、GⅡ.P16/GⅡ.13型2株(5.56%)、GⅡ.P7/GⅡ.6和GⅡ.16各1株(2.78%)。2013年暴发疫情病例所测35株诺如病毒共4种基因型,依次为28株GⅡ.Pe/GⅡ.4型(80.0%)、4株GⅡ.7(11.43%)、3株GⅡ.12/GⅡ.3(8.57%)。结论诺如病毒是无锡地区非细菌性腹泻最常见的病原体,无锡地区诺如病毒流行株具有多种基因型,存在不同基因型间重组株。GⅡ.Pe/GⅡ.4型(Sydney_2012)为2013年无锡地区绝对优势流行株。

Objective To investigate the epidemic characteristics and dominant genotype of norovirus in Wuxi. Methods Fecal specimens and cases samples were respectively collected from 409 acute diarrhea patients in sentinel hospitals of Wuxi and 9epidemic outbreaks of norovirus. Real- time fluorescence quantification PCR was used to detect GⅠ and GⅡ gene of norovirus,and gene fragments from GⅡ positive specimens were further amplified and sequenced. Results The positive rate of norovirus in acute diarrhea patients was 9. 78%（ 40 /409）,and there were 5 genotypes in 36 norovirus,including 28 strains of GⅡ.Pe / GⅡ. 4（ 77. 78%）,4 strains of GⅡ. P12 / GⅡ. 3（ 11. 11%）,2 strains of GⅡ. P16 / GⅡ. 13（ 5. 56%）,1 strain of GⅡ.P7 / GⅡ. 6（ 2. 78%） and 1 strain of GⅡ. 16（ 2. 78%）. There were 4 genotypes in 35 norovirus in the epidemic outbreaks,including 28 strains of GⅡ. Pe / GⅡ. 4（ 80. 0%）,4 strains of GⅡ. 7（ 11. 43%）,3 strains of GⅡ. 12 / GⅡ. 3（ 8. 57%）. Conclusion Norovirus,with many kinds of genotypes,is the most common pathogen of non bacterial diarrhea in Wuxi area. Gene recombination generate different genotypes. GⅡ. Pe / GⅡ. 4 genotype（ Sydney_2012） is the dominant strain in Wuxi in 2013.