2012年至2016年上海市某医院门诊急性腹泻婴幼儿中经典人星状病毒的流行病学特征

Epidemiology of classic human astrovirus among infants and young children with acute diarrhea in a hospital outpatient in Shanghai,2012-2016

目的分析5岁以下急性腹泻婴幼儿中经典人星状病毒(human astrovirus,HAstV)的流行病学特点,了解经典HAstV在婴幼儿腹泻发病中的作用。方法收集2012年1月至2016年12月于上海复旦大学附属儿科医院门诊就诊的1010例急性腹泻婴幼儿(年龄≤5岁)的粪便标本1010份,采用反转录聚合酶链反应或聚合酶链反应检测粪便标本中的经典HAstV、A组轮状病毒、诺如病毒和腺病毒,通过基因测序和进化树分析确定HAstV的型别和亚型。结果5年经典HAstV的总检出率为2.7%(27/1010)。2012年、2013年、2014年、2015年和2016年检出率分别为6.9%(10/144)、3.5%(5/144)、2.1%(3/144)、1.5%(4/265)、1.6%(5/313)。HAstV感染腹泻患儿的年龄段集中在0~36月龄,占96.3%(26/27)。除2016年外,其他年份检出的经典HAstV集中在秋冬季。检出的27例经典HAstV感染腹泻患儿的基因型均为HAstV-1型,亚型分别为HAstV-1a和HAstV-1b,以HAstV-1a亚型(63.0%,17/27)为主。腹泻患儿中经典HAstV的感染以单独感染为主,占77.8%(21/27);混合感染以HAstV与A组轮状病毒(3例)和腺病毒(2例)的两两混合感染为主,还有1例混合感染为HAstV、A组轮状病毒和腺病毒的同时感染。结论HAstV感染主要集中在0~36月龄婴幼儿。经典HAstV流行基因型别单一,但亚型处于动态变化中,需长期连续监测经典HAstV在腹泻婴幼儿中的流行情况及其基因型别,以防暴发性腹泻的发生。

Objective To investigate the epidemiological characteristics of classic human astrovirus(HAstV)among children under five years old with acute diarrhea,and to understand the role of HAstV in children acute diarrhea.Methods A total of 1010 fecal specimens were collected in 1010 outpatients under five years old with acute diarrhea admitted to Children′s Hospital of Fudan University,Shanghai from January 2012 to December 2016.Reverse transcription polymerase chain reaction(PCR)or PCR was used for screening classic HAstV,group A rotavirus,norovirus and adenovirus.Genotypes of classic HAstV were determined by nucleotide sequencing and phylogenetic tree analysis.Results The overall positive rate of classic HAstV was 2.7%(27/1010).The detection rates of classic HAstV from 2012 to 2016 were 6.9%(10/144),3.5%(5/144),2.1%(3/144),1.5%(4/265)and 1.6%(5/313),respectively.Almost 96.3%(26/27)of children infected with HAstV were 0 to 36 months of age.The prevalence of classic HAstV infections displayed a typical autumn/winter seasonality except in 2016.All the positive classic HAstV strains were genotyped as HAstV-1 with two lineages of HAstV-1a and HAstV-1b.Among them,the lineage of HAstV-1a was the predominant subtype(63.0%,17/27).There were 77.8%(21/27)of the children with acute diarrhea only infected with classic HAstV,whereas for the remaining cases a variety of other enteric viruses were detected(three cases co-infected with HAstV and group A rotavirus,two cases co-infected with HAstV and adenovirus,and one case co-infected with HAstV,group A rotavirus and adenovirus).Conclusions Children infected with HAstV are mainly less than 36 months of age.Although the genotype of classic HAstV detected in this study is single,but the lineages are in a state of dynamic change.Long-time and continuous monitor for the epidemiology of classic HAstV is needed to avoid outbreak of diarrhea in children.