陕西省2012-2014年甲型H1N1流感的基因特性研究

Epidemiological and genetic characteristics of influenza A(H1N1)virus in Shaanxi in 2012-2014

目的了解陕西省2012-2014年甲型H1N1流感病毒的流行特征和血凝素（HA）、神经氨酸酶（NA）的基因特征。方法收集陕西省全省18家哨点医院流感样病例的监测资料和12家流感网络实验室病原学检测结果。用RT-PCR方法对部分甲型H1N1流感病毒进行HA、NA基因序列扩增,利用生物软件对序列特征及变化情况进行分析。结果陕西省2012-2014年度甲型H1N1为当年流行的优势株,占流感样病例的4.73%,占流感病毒阳性的43.44%,流行高峰时间为每年的11月~次年的2月。通过测序得到的各样本HA序列为1701bp,编码566个氨基酸,NA序列为1710bp,编码469个氨基酸,两年间分别有16、21个氨基酸发生变异,其中在142、180、202、220位点出现变异发生在HA抗原决定簇,HA的受体结合位点、潜在糖基化位点比较稳定,两年间没有发生变化,2012-2013年度毒株的NA序列增加了一个42（NQSQ）潜在的糖基化位点,NA序列没有发现耐药位点变异。结论 2012-2014年度陕西省甲型H1N1处于低流行状态,为流行的优势株,甲型H1N1的HA、NA氨基酸位点的变异属于抗原漂移,甲型H1N1流感与疫苗的匹配程度逐年降低。

Objective To understand the epidemiological and genetic characteristics of influenza A（H1N1）virus in Shaanxi province from 2012 to 2014. Methods Surveillance data of influenza-like cases from 18 sentinel hospitals and the etiological testing results in 12 influenza network laboratories were collected in Shanxi.HA and NA genes of H1N1 virus were amplified,sequenced and analyzed by bioinformatics software. Results Influenza A（H1N1）was found to be dominant in Shaanxi from 2012 to 2014,accounting for4.73% of influenza-like cases and 43.44% of influenza virus positive cases.positive,the influenza A（H1N1）peak time was from November to February of the next year.The The peak season was from November to February.The HA and NA genes were 1701 bp and 1710 bp long which coded 566 and 469amino acid.In two years,there were 16 and 21amino acids mutations found in HA and NA genes.The mutations in 142,180,202 and 220sites were at antigen determinants,while the receptor binding locus and potential glycosylation sites were relatively stable,no change was found.An extra potential glycoslytion site 42（NQSQ）was identified in NA gene of strains collected from 2012 to 2013,while no mutation on drug resistant sites was found.Conclusions Influenza A（H1N1）is found to be a dominant strain in Shanxi from 2012 to 2014,but not very much active.The mutations on the amino acid sequences of HA and NA genes are considered as antigen drifts,and the matching rates between the influenza A（H1N1）virus and the vaccine decrease annually.