2016年北京地区急性腹泻患儿感染人博卡病毒流行特征及分子进化研究

Epidemiological and phylogenetic analysis of human bocavirus from children with acute gastroenteritis in Beijing in 2016

目的了解2016年北京地区急性腹泻患儿感染人博卡病毒(HBoV)流行及遗传进化特征。方法采集北京地区哨点医院2016年<60月龄急性腹泻患儿粪便标本,用巢式PCR检测HBoV,通过测序和Blast比对确定病毒型别,并进行遗传进化分析;采用实时荧光PCR对A组轮状病毒、诺如病毒、肠道腺病毒、星状病毒进行检测,分析混合感染情况。结果 354份粪便标本中,HBoV阳性26份,阳性率为7.34%,其感染无明显季节分布,<2岁患儿占84.62%。HBoV与其他腹泻病毒混合感染率为38.46%,以混合轮状病毒感染为主。进化分析表明,HBoV1、2、3型感染分别为15、10、1例,未检出HBoV4型。HBoV2序列均独立于HBoV2A和HBoV2B亚型分支,位于一个新的HBoV2亚型分支上。结论 2016年北京地区腹泻患儿感染HBoV包括3种型别(1-3型),2岁以内患儿是高发人群。HBoV2在进化树上位于一个新的亚型分支。

Objective To investigate the epidemiological and phylogenetic characteristics of human bocavirus（HBoV）from children presenting with acute gastroenteritis in Beijing in 2016. Methods Stool samples from children under 60 months of age with acute gastroenteritis were collected from sentinel hospitals in Beijing from January to December 2016.Samples were examined for presence of HBoV using nested-PCR and HBoV was phylogenetically analyzed.Stool samples were also tested for group A rotavirus,norovirus,enteric adenovirus,and astrovirus using real-time PCR to identify mixed infections Results Twenty-six of 354 stool samples（7.34%）tested positive for HBoV and HBoV was detected year-round.Seasonal characteristics were not evident.Eighty-four-point-six-two percent of children were under 2years of age.A mixed infection of HBoV and some other virus was noted in 38.46% of the samples;HBoV was most often present with rotavirus.Phylogenetic analysis revealed that HBoV1 in 15patients,HBoV2 in 10,and HBoV3 in 1.HBoV4 was not detected.All of the HBoV2 sequences were independent of HBoV2 Aand HBoV2Bbranches and were located in a new HBoV2 subtype cluster. Conclusion Three types of HBoV（1-3）were identified in children with acute gastroenteritis in Beijing in 2016.Most cases involved children under 2years of age,and all of the HBoV2 sequences were located in a new HBoV2 subtype cluster.