2015-2021年宁夏腹泻病例中人星状病毒分子流行病学特征分析

Epidemiological and Genetic Characterization of Human Astrovirus in Patients with Diarrhea in Ningxia,China,2015–2021

基于宁夏食源性疾病监测系统研究宁夏地区2015-2021年15家哨点医院腹泻病例中的人星状病毒(Human astrovirus,HAstV)感染状况,流行病学特点和基因特征。对收集的粪便标本,采用Real-time PCR方法筛选出的HAstV阳性标本,进行了回顾性分析。通过逆转录PCR对保存的HAstV阳性样本进行测序和基因分型,确定宁夏地区HAstV流行的基因型别和遗传进化。2015-2021年共收集腹泻病例标本8586例,HAstV阳性率为5.9%(513例),其中单独HAstV感染293例(占57%),和其它病毒共同感染220例(占42%),共同感染中与轮状病毒和诺如病毒GII组感染最多见,其次是两种以上病毒感染。感染发生在所有年龄组,5岁以下儿童的阳性率最高(8.0%),11-20岁年龄组阳性率最低(1.9%)。感染全年发生,一月和六月高发。对保存的168份HAstV单独阳性标本进行测序分析,测序获得94条HAstV基因序列,经鉴定为5种基因型别,分别是HAstV-1、HAstV-2、HAstV-3、HAstV-4、 HAstV-5,其中HAstV-1型为最常见的基因型(占61.7%),其次是HAstV-5(占19.1%)和HAstV-4(占15.9%)。系统发育分析显示HAstV-1分别属于HAstV-1a和HAstV-1b亚型,HAstV-1a较常见。HAstV-5和HAstV-4分别属于HAstV-5c和HAstV-4c亚型。全人群均可感染星状病毒,但主要受影响为5岁以下儿童。HAstV-1型是宁夏地区流行的主要型别,同时存在HAstV-1a和HAstV-1b、HAstV-4c、HAstV-5c共循环。

The objective is to study the epidemiological characteristics and genetic characteristics of human astrovirus(HAstV)infection in patient with diarrhea from the Ningxia Foodborne Disease Surveillance System which includes 15 sentinel hospitals.Methods The collected stool specimens were tested with Real‐time PCR to detect HAstV.HAstV‐positive specimens were sequenced and genotyped by reverse transcription PCR.A total of 8586 specimens were collected from 2015 to 2021 with HAstV‐positive rate of 5.9%(513 cases),of which 293 cases(57%)were astrovirus infections alone and 220 cases(42%)were co‐infected with other viruses.Infections occurred in all age groups,with the highest positivity rate of HAstV in children under the age of five(8.0%),and the lowest positive rate of HAstV was 1.9%in the age of eleven‐twenty.Infections occurred throughout the year,with high incidence in January and June.The sequencing analysis of 168 preserved HAstV single positive specimens was performed,and 94 HAstV gene sequences were analyzed,which were identified as five genotypes,including HAstV‐1,HAstV‐2,HAstV‐3,HAstV‐4,and HAstV‐5.HAstV‐1 was the most common genotype(61.7%),followed by HAstV‐5(19.1%),and HAstV‐4(15.9%).Phylogenetic analysis showed that HAstV‐1 belonged to HAstV‐1a and HAstV‐1b subtypes,with higher prevalence of HAstV‐1a.HAstV‐5 and HAstV‐4 belonged to HAstV‐5c and HAstV‐4c subtypes.The whole population can be infected with astrovirus,but the mainly affected group is children under five years old.HAstV‐1 is the dominant type in Ningxia,China,and there is co‐circulation of HAstV‐1a and HAstV‐1b,HAstV‐4c and HAstV‐5c.