3例甲、乙型流感病毒共感染患者临床特点及病毒分子特征

Clinical features of three patients with co-infection of influenza A and B viruses and the molecular characteristics of the viruses

目的探讨3例甲、乙型流感病毒共感染患者的临床特点及病毒基因变异情况.方法采用荧光定量PCR方法对呼吸道标本进行核酸检测与分型,扩增流感病毒全基因组后进行高通量测序,通过生物信息学方法对病毒的血凝素(hemaglutinin,HA)、神经氨酸酶(neuramindase,NA)分子特征进行分析,同时收集、分析患者临床资料.结果3例患者均合并1种以上基础疾病,2例出现双肺病变,2例死亡.共感染甲、乙型流感病毒中,甲型流感毒株均属于H1N1亚型6B.1组,有3个抗原位点发生了氨基酸变化,耐药位点未见明显变化.乙型流感病毒均属于Yamagata系,未发现耐药位点的突变.结论共感染甲、乙型流感病毒且合并基础疾病及肺/肝功能不全的患者,预后不良,病毒HA、NA重要的氨基酸位点相对保守,未发生变种.

Objective To analyze the clinical features of three patients with co-infection of influenza A and influenza B viruses,and to analyze the gene mutations of the viruses.Methods Fluorescence quantitative PCR was used to detect and classify nucleic acids in respiratory specimens.The whole genomes of influenza virus were amplified and were sequenced by next-generation sequencing.The molecular characteristics of hemaglutin(HA)and neuramindase(NA)of the viruses were analyzed by bioinformatics methods.The clinical data of the patients were collected and analyzed simultaneously.Results All three patients had at least one underlying disease.Lesions in both lungs were found in two patients and two patients died.For the co-infected influenza viruses,influenza A virus strains belonged subtype H1N1,genetic group 6B.1.Three variations of amino acid in antigenic locus were detected while no significant change in drug-resistance locus was observed.The influenza B virus strains belonged to Yamagata lineages,no significant change was observed in drug-resistance locus.Conclusions The patients with co-infection of influenza A and B virus accompanied by abnormal lung/liver function had poor prognosis.The HA and NA genes were relatively conservative and no new variants were found.