北京市朝阳区2011—2017年5岁以下患儿腹泻标本中诺如病毒分子流行病学特征

Molecular epidemiology of norovirus among infants with diarrhea in Chaoyang district, Beijing from 2011 to 2017

目的研究北京市朝阳区感染性腹泻患儿中诺如病毒(Norovirus,NoV)的分子流行病学特征。方法针对北京市朝阳区2011年4月至2017年12月收集的5岁以下腹泻患儿粪便标本,利用PCR方法检测其中NoV聚合酶-衣壳区,并对扩增产物进行序列测定、NoV系统进化分析和型别鉴定,结合结果进行统计分析。结果完成对151例NoV阳性标本的扩增和测序,男女比例为2.28∶1,平均年龄1.72岁,检出较高的时间为每年春季(3~5月份)和秋冬季(9~12月份)。经系统分析共发现14种NoV基因亚型,类别及构成比依次为GII.Pe/GII.4(47.68%)、GII.P12/GII.3(20.53%)、GII.P4/GII.4(17.22%)、GII.P16/GII.2(3.31%)、GII.P12/GII.12(1.99%)、GII.P17/GII.17(1.99%)、GII.P16/GII.13(1.32%)、GII.P7/GII.7(1.32%)、GII.P7/GII.6(1.32%)、GII.P2/GII.2(0.66%)、GII.P21/GII.21(0.66%)、GII.Pg/GII.12(0.66%)、GI.Pa/GI.3(0.66%)、GI.P6/GI.6(0.66%)。结论北京市朝阳区5岁以下腹泻患儿NoV感染具有型别多样性的特征,且与暴发毒株型别在发生时间上相互印证。应加强对儿童NoV腹泻的监测。

Objective To investigate the genetic characteristics of human norovirus (NoV) among infants under 5 years of age with diarrhea in Chaoyang District, Beijing from 2011 to 2017. Methods NoV-positive stool samples were collected from 2011 to 2017 in this region. The partial RdRp and VP1 genes were amplified and sequenced. Multi-sequence alignment was performed and phylogenetic tree was constructed using Mega software. Results A total of 151 samples were sequenced and analyzed. The ratio of male and female was 2.28∶1 with mean age of 1.72 years. Fourteen NoV subtypes were detected, including GII.Pe/GII.4 (47.68%), GII.P12/GII.3 (20.53%), GII.P4/GII.4 (17.22%), GII.P16/GII.2 (3.31%), GII.P12/GII.12 (1.99%), GII.P17/GII.17 (1.99%), GII.P16/GII.13 (1.32%), GII.P7/GII.7 (1.32%), GII.P7/GII.6 (1.32%), GII.P2/GII.2 (0.66%), GII.P21/GII.21 (0.66%), GII.Pg/GII.12 (0.66%), GI.Pa/GI.3 (0.66%) and GI.P6/GI.6 (0.66%). Conclusions NoV genetic diversity was found among infants under 5 with diarrhea in Chaoyang district, Beijing. The subtypes from surveillance and those from epidemics occurred in chronological order. The surveillance should be strengthened for early detection of new subtype for monitoring the epidemic and vaccine design.