一起甲型H1N1和H3N2流感病毒混合感染调查研究

目的 从病例临床特征、抗体变化规律及病原学检测等多角度分析一起由甲型H1N1和H3N2流感病毒混合感染引起暴发疫情的流行特征,为有效控制疾病的发生与蔓延提供科学依据.方法 采用回顾性调查和现场流行病学调查方法进行问卷调查,利用RT-PCR和血凝抑制试验分别进行流感病毒和血清抗体检测.结果 45例流感样病例中,确诊40例,其中22例为甲型H1N1流感、12例为季节性H3N2型流感、6例为H1N1和H3N2病毒混合感染.不同病毒感染病例的临床表现差异无统计学意义.序列比对分析显示,混合病毒感染和单一病毒感染者的甲型H1N1和季节性H3N2病毒基因序列没有差异.同时分析表明,所有流感病例的病毒株均对金刚烷胺耐药,对奥司他韦(达菲)有效.患者的双份血清血凝抑制试验检测表明,暴发由甲型H1N1和H3N2流感病毒混合感染引起.结论 这是一起由甲型H1N1和H3N2流感病毒混合感染引起的疫情,甲型H1N1病毒在传播过程中可能较H3N2更具有优势.

Investigation on mixed infection of pandemic H1N1 and seasonal H3N2 Viruses

Objective To understand the epidemiological characteristics in an outbreak of mixed infection of H1N1 and H3N2 viruses through analysing the clinical features,antibody changes,pathogenic detections and to provide basis for the disease prevention and control measures.Methods Epidemiological and clinical data were collected by in-terviewing patients and retrieving medical records.Viruses were identified by RT-PCR assays followed by sequence analy-sis.Hemagglutination inhibition(HI)test was used to detect antibodies for both viruses.Results In 45 people with influenza-like illness,40 were laboratory-confirmed influenza cases,among which 22 were infected by pandemic H1N1virus,12 by seasonal H3N2 virus,and 6 by both viruses.The clinical manifestations of patients with different virus infection were essentially similar.There was no substantial difference in genomic sequences of either pandemic H1N1 or seasonal H3N2 virus between patients with the mixed and single infection.Sequence analyses revealed that all the detected viruses were oseltamivir-sensitive but adamantane-resistant.HI tests of paired sera confirmed the mixed infection within the outbreak.Conclusions Co-circulation of both viruses lead to a mixed infection influenza pandemic.However,pandemic H1N1 virus is priority in prevalence in the course of transmission.