人感染H7N9禽流感26例临床特征与病毒基因分析研究

目的探讨人感染H7N9禽流感病毒患者的流行病学和临床特征,以及病毒分子生物学特征。方法收集湖南省2013、2014年确诊的26例人感染H7N9禽流感病毒患者的资料,对人和禽分离的H7N9病毒进行鉴定和测序分析。结果26例患者中,发热和咳嗽是最常见的起病症状,所有患者均存在肺炎;20例(76.92%)出现急性呼吸窘迫综合征(ARDS),25例(96.15%)初诊时白细胞下降或正常,发病至开始进行抗病毒治疗的平均时间为10 d。10例死亡,病死率达38.46%。患者分离的H7N9病毒株测序分析表明,发生了H7基因Gln226Leu和Gly186Val替换,PB2基因Asp701Asn突变。结论急性呼吸系统损害是人感染H7N9禽流感的主要临床表现,活禽暴露是人感染H7N9禽流感的重要危险因素,H7N9禽流感病毒基因发生了部分位点的适应性突变,更容易从禽类向人跨种传播引起人类严重疾病,需加强病原学监测。

Clinical features of 26 patients with H7N9 avian influenza and characteristics of viral gene

ObjectiveTo evaluate the clinical, epidemiological, and viral molecular biology features of 26 patients infected with H7N9 avian influenza A virus.MethodsClinical and epidemiological data of 26 patients with confirmed avian influenza A (H7N9) infection in 2013 and 2014 were collected, virus isolated from human and poultry were identified and typed through sequencing.ResultsOf 26 patients, fever and cough were the most common symptoms, all patients had pneumonia; 20 patients（76.92%）developed acute respiratory distress syndrome(ARDS); 25 patients (96.15%) had leucopenia or normal leukocytes at the initial diagnosis; treatment with antiviral drugs was initiated in 25 patients at a median of 10 days after the onset of illness；10 patients (38.46%) died. Gene sequencing indicated Gln226Leu and Gly186Val substitutions in human virus H7 gene and the PB2 Asp701Asn mutation. ConclusionAcute respiratory system damage is the main clinical manifestation of avian influenza (H7N9) virus infection in humans， live poultry exposure is an important risk factor for H7N9 infection in humans, adaptive mutation occurred at partial site of avian virus gene, which can be more easily be spread from birds to human and cause serious diseases, it is necessary to strengthen the pathogen monitoring.