引起一起发热疫情的人腺病毒4a型基因特征分析

目的了解引起一起发热疫情的人腺病毒4a型基因特征。方法2019年10月，北京市通州区某小学出现发热疫情，采集病例的咽拭子标本，提取标本核酸作为模板，利用实时荧光PCR方法检测32种呼吸道病毒和细菌。 对于腺病毒检测阳性的标本核酸，利用腺病毒特异性引物扩增3个基因（Fiber、Hexon和Penton）的片段并测序，采用局部序列比对基本检索工具（BLAST）比对序列，进行进化关系分析。结果采集的6份病例标本中，腺病毒全部阳性，其他检测的呼吸道病毒和细菌均为阴性。 Fiber、Hexon和Penton基因序列比对结果显示，6份标本中的腺病毒均为4a基因型。进化分析显示，该病毒与近年来美国流行的4a型腺病毒高度同源。结论人腺病毒4a型在北京市可以引起呼吸道发热疫情。

Genetic characteristics of human adenovirus 4a causing an epidemic of febrile illness

ObjectiveTo understand the genetic characteristics of human adenovirus 4a causing an epidemic of febrile illness occurred in a primary school in Tongzhou district of Beijing in October, 2019.MethodsThe oropharyngeal swabs were collected from the febrile illness cases for the detections of 32 kinds of respiratory viruses and bacteria by real-time PCR. The Fiber, Hexon and Penton gene fragments were amplified and sequenced by PCR for adenovirus positive specimens. The Fiber, Hexon and Penton gene sequences were analyzed by BLAST in NCBI. A phylogenetic tree was constructed by using Fiber, Hexon and Penton gene sequences with software BioEidt 7.2.5 and MEGA 6.06.ResultsThe oropharyngeal swabs of 6 febrile illness cases were all positive for adenovirus in real-time PCR. There were no other respiratory pathogens detected in the oropharyngeal swabs. Fiber, Hexon and Penton gene sequence alignment results indicated that the adenovirus strains from the 6 cases belonged to adenovirus 4a. The phylogenic tree analysis indicated that the adenoviruses isolated in this epidemic shared high homology with adenovirus 4a circulating in USA in recent years.ConclusionThis epidemic of febrile illness was caused by human adenovirus 4a.