一起新甲型H1N1流感暴发疫情的流行病学和病原学分析

目的 对2009年11月下旬北京市延庆县一封闭式管理的集体单位暴发的一起急性呼吸道感染疫情进行流行病学和病原学分析.方法 采集患者咽拭子标本,用Real-Time RT-PCR方法进行新甲型,季节性甲1、季节性甲3和乙型流感病毒的核酸检测.对ct＜30的阳性标本进行全长NA基因编码区扩增、克隆、测序及进化树分析.结果 27份标本有22份（81.48%）real-Time RTPCR为新甲型H1N1阳性;暴发株全长神经氨酸酶（NA）基因核苷酸和氨基酸序列同源99.9%和99.8%,与A/Tomsk/05/2009（H1N1）序列同源最高达100%,且NA的酶活性位点及其周围辅助位点、糖基化位点未见氨基酸替换现象.结论 此次暴发疫情主要由同一新甲型H1N1流感病毒毒株传播所致;同一病毒株在同一时期不同地域流行;高度保守的NA基因氨基酸序列是抗流感药物研发的重要靶点.

The epidemiologic and virological analysis of an outbreak of swine-origin influenza

Objective To investigate epidemiologic and virological analysis of the outbreak of swine-origin H1N1 in Yanqing, Beijing. Methods Nasopharyngeal swab specimen were collected and adopted by real time RT-PCR to detect the swine-origin H1N1 neucleic acid. Furthermore, full length NA coding sequence were amplified with high fidelity DNA polymerase and then cloned into pCDNAII. Sequence and phylogenetic tree analysis were conducted. Results The major pathogen of this outbreak was newly emerged 2009 H1N1. NA sequence analysis showed this outbreak was caused by the same virus strain prevalent in other regions at the same period. It was shown that catalytic and glycosylation sites were highly conserved. Conclusion This outbreak was cause by the same swine-origin H1N1 virus strain. Furthermore,highly conserved catalytic and glycosylation sites of neuraminidase provides targets for the development of antiviral drugs.