2018年北京市西城区呼吸道腺病毒感染疫情流行病学和病原学特征分析

Epidemiological and Pathogenic Characteristics of Respiratory Tract Infection in Xicheng District,Beijing City,China in 2018

2018年5~9月,北京市西城区五所小学先后共报告了5起呼吸道感染集中发热疫情。为了解报告的5起疫情的流行病学和病原学特征,开展了现场调查,并采集病例咽拭子标本,使用荧光定量PCR方法检测17种常见呼吸道病毒进行病原学筛查,对鉴定为人腺病毒(Human adenovirus,HAdV)阳性的标本进行病毒分离,并分别扩增六邻体蛋白基因Loop2区域以及三个衣壳蛋白(五邻体基座蛋白、六邻体蛋白和纤维蛋白)基因全长,进行HAdV型别的初筛和确认,同时与GenBank数据库中国内外HAdV-3流行株序列进行比对分析。结果显示,5起集中发热疫情的致病原均为HAdV-3。进一步研究发现,全球流行HAdV-3可划分为Clade1和Clade2两个进化分支,2004年至今我国流行的HAdV-3病毒株均属于Clade2进化分支,也是近年全球优势流行株。两个进化分支HAdV-3病毒株在三个基因序列上均高度保守。本研究为我国呼吸道HAdV防控,以及HAdV-3型疫苗研发提供了基础科学数据。

From May to September 2018,five primary schools in Xicheng District(Beijing City,China)reported five successive aggregation-fever events of respiratory-tract infection. To understand their epidemiological and pathogenic characteristics,field investigations were carried out. Meanwhile,throat-swab samples were collected, and 17 common respiratory viruses were detected by fluorescent quantitative polymerase chain reaction(PCR)for pathogen screening. Virus isolation was undertaken on human adenovirus(HAdV)-positive samples and complete sequences of three capsid proteins(penton base,hexon and fiber)were amplified to further confirm the type of HAdV. Comparison analyses were undertaken between the viruses isolated in the present study and strains from the GenBank database. Results showed that HAdV-3 was the main pathogen responsible for the five aggregation-fever events. Further research revealed that HAdV-3 worldwide could be divided into two evolutionary branches(clade 1 and clade 2). HAdV-3 strains that have been prevalent in China since 2004 belonged to clade 2,which is also the predominant strain circulating worldwide in recent years. Both HAdV-3 strains within the two branches were highly conserved in all three gene sequences. The present study provides basic scientific data for the prevention and control of respiratory HAdV in China,as well as development of a vaccine for important types of HAdV.