2012-2014年乌鲁木齐市5岁以下急性腹泻儿童患者诺如病毒感染及基因型研究

Molecular epidemiology of norovirus infection in hospitalized children with acute gastroenteritis in Urumqi,Xinjiang,2012-2014

目的了解2012—2014年新疆维吾尔自治区(新疆)乌鲁木齐市<5岁住院儿童患者诺如病毒的分子流行病学特征。方法收集2012—2014年乌鲁木齐市895例<5岁急性腹泻儿童患者粪便标本和流行病学资料,应用实时荧光反转录聚合酶链式反应(RT-PCR)进行诺如病毒检测,阳性样本通过RT-PCR扩增、测序和序列分析。结果诺如病毒的检出率为16.8%(150/895),不同年份阳性率差异有统计学意义(χ2=21.080,P<0.05);不同年龄组阳性率差异有统计学意义(χ2=13.367,P=0.020)。137份样本获得聚合酶区序列,其中89份获得衣壳蛋白区序列。聚合酶区和衣壳区分别包括11和9个基因型。根据89株双分型结果,GⅡ.4 Den Haag 2006b和GⅡ.Pe/GⅡ.4 Sydney 2012分别占21.3%和32.6%,GⅡ.P12/GⅡ.3占29.2%。根据衣壳区分型结果,在GⅡ.4基因型中,2012—2014年GⅡ.4 DenHaag 2006b所占比例分别为90.0%、0%和0%;GⅡ.Pe/GⅡ.4Sydney 2012所占比例分别为10.0%、100%和100%。结论新疆乌鲁木齐市急性腹泻儿童诺如病毒具有遗传多样性;GⅡ.Pe/GⅡ.4 Sydney 2012在新疆地区出现,逐渐替代GⅡ.4 DenHaag 2006b成为新的流行优势株。

Objective To understand the molecular epidemiological characteristics of norovirus infection in hospitalized children under〈 5 years old from 2012 to 2014 in Xinjiang.Methods Fecal specimens and epidemiological data were collected from 895 sick children aged5 years hospitalized in Urumqi Hospital due to acute diarrhea from 2012 to 2014,and Real-time fluorescence quantitative-polymerase chain reaction（RT-PCR）was performed for norovirus detection.The positive specimens were amplified by reverse transcription-polymerase chain reaction（RT-PCR）and sequenced.Results Of 895 specimens tested,150（16.8%）were detected as norovirus positive.The differences in positive rate among different years were significant（P〈0.05）and the differences in positive rate among different age groups were significant too（P=0.020）.Among the strains,137 got the polymerase region sequencing.Out of 137 strains,89 got the capsid protein region sequencing.The polymerase and capsid regions included 11 and 9 genotypes,respectively.GⅡ.4 DenHaag 2006b and GⅡ.Pe/GⅡ.4 Sydney 2012 accounted for 21.3%and 32.6%,respectively,and GⅡ.P12/GⅡ.3 accounted for 29.2%,according to the typing results of 89 strains in two regions.Among GⅡ.4 genotypes,the proportion of GⅡ.4 DenHaag 2006b was90.0%,0%and 0%from 2012 to 2014,respectively.GⅡ.Pe/GⅡ.4 Sydney 2012 accounted for 10.0%,100%and 100%,respectively.Conclusion The genetic diversity of norovirus in children with acute diarrhea in Urumqi of Xinjiang was found.GⅡ.Pe/GⅡ.4 Sydney appeared in Xinjiang in 2012,gradually replacing GⅡ.4 DenHaag 2006b as a new epidemic predominant strain.