National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, State Key Laboratory for Molecular Virology & Genetic Engineering, 27, Nanwei Road, Room 507, Xuanwu District, Beijing, 100050, PR China.
Virol J. 2011 Jan 18;8:23. doi: 10.1186/1743-422X-8-23.
Pneumonia caused by adenovirus infection is usually severe especially with adenovirus serotype 7 commonly associated with lower respiratory tract disease outbreaks. We reported an outbreak of 70 cases of severe pneumonia with one death of infants in Shaanxi Province, China. Sampling showed adenovirus 7 (Ad7) as the primary pathogen with some co-infections.
Two strains of adenovirus and two strains of enterovirus were isolated, the 21 pharynx swabs showed 14 positive amplifications for adenovirus; three co-infections with respiratory syncytial virus, two positive for rhinovirus, one positive for parainfluenza 3, and four negative. Adenovirus typing showed nine of the nine adenovirus positive samples were HAdV-7, three were HAdV-3 and two were too weak to perform sequencing. The entire hexon gene of adenovirus was sequenced and analyzed for the two adenovirus serotype 7 isolates, showing the nucleic acid homology was 99.8% between the two strains and 99.5% compared to the reference strain HAdV-7 (GenBank accession number AY769946). For the 21 acute phase serum samples from the 21 patients, six samples had positives results for ELISA detection of HAdV IgA, and the neutralization titers of the convalescent-phase samples were four times higher than those of the acute-phase samples in nine pairs.
We concluded adenovirus was the viral pathogen, primarily HAdV-7, with some co-infections responsible for the outbreak. This is the first report of an infant pneumonia outbreak caused by adenovirus serotype 7 in Shaanxi Province, China.
腺病毒感染引起的肺炎通常较为严重，尤其是腺病毒血清型 7 型常与下呼吸道疾病爆发有关。我们报告了中国陕西省一起 70 例婴幼儿重症肺炎暴发的情况，其中 1 例死亡。采样显示腺病毒 7 型（Ad7）为主要病原体，存在一些合并感染。
分离出两株腺病毒和两株肠道病毒，21 份咽拭子中 14 份显示腺病毒阳性扩增；三种合并感染呼吸道合胞病毒、两种合并感染鼻病毒、一种合并感染副流感 3 型、四种为阴性。腺病毒分型显示 9 份腺病毒阳性样本中 9 份为 HAdV-7、3 份为 HAdV-3，2 份因太弱而无法进行测序。对两株腺病毒 7 型进行了全六邻体基因测序和分析，结果显示两株腺病毒的核酸同源性为 99.8%，与参考株 HAdV-7（GenBank 登录号 AY769946）相比为 99.5%。对 21 例患者的 21 份急性期血清样本进行 ELISA 检测 HAdV IgA，有 6 份样本呈阳性结果，9 对恢复期样本的中和滴度比急性期样本高 4 倍。
我们认为腺病毒是病毒病原体，主要为 HAdV-7，存在一些合并感染导致了此次暴发。这是中国陕西省首次报告由腺病毒 7 型引起的婴幼儿肺炎暴发。
