家庭聚集性人感染高致病性禽流感病例的确认及其病原的HA基因特征分析  

Confirmation of human cases in family clusters infected with highly pathogenic avian influenza virus and analysis of the HA gene characteristics

作　　者：潘浩[1,2] 祖荣强[1] 朱凤才[1] 李亮[1] 史智扬[1] 鲍昌俊[1] 李显[1] 邓斐[1] 汪华[1] 

机构地区：[1]江苏省疾病预防控制中心,南京210009 [2]上海市疾病预防控制中心

出　　处：《中国人兽共患病学报》2009年第9期859-864,869,共7页Chinese Journal of Zoonoses

摘　　要：目的确认江苏南京市2007年12月期间二例家庭聚集性人感染高致病性禽流感病例,探究家庭聚集性病例的临床变化规律及其病毒的基因特征。方法通过知情人访谈和查阅病志方式开展流行病学调查。同时采集二病例咽拭子等标本,运用荧光定量RT-PCR法进行H5N1基因检测,并开展病毒分离,分析血凝素(HA)基因特征。结果流行病学调查结果表明二病例为家庭聚集性病例,首发病例病后第5d出现"白肺",病后第8d后死亡,白细胞和血小板呈进行性下降。第二例病人存活,肺部未出现遍及全肺的大面积实变。二病例呼吸道标本H5N1基因检测均为阳性,培养物经鉴定均为H5亚型。二分离株HA基因同源性为100%,同我国浙江、安徽等地人源分离株接近(99.0%,98.9%),同江苏禽源分离株同源性达98.7%。二分离株经系统发生树分析均为CladeⅡ系的2.3.4基因亚群,HA1和HA2连接肽及细胞受体结合位点仍表现为禽源特性。结论二病例为人感染高致病禽流感H5N1病毒家庭聚集性病例,为有限的直系亲属间的人与人传播模式,分离株的HA基因特征仍为禽源性。This article deals with the confirmation of two cases in family clusters infected with highly pathogenic avian influenza virus in Nanking city of Jiangsu province in November 2007 by describing their clinical manifestations analyzing their genetic characteristics of viruses isolated from these cases. Epidemiological study was conducted by means of interviews and reference of related records. In addition, samples of patients, such as the throat swabs were collected and tested with real time RT-PCR to detect the viral nucleic acid of the A/H5N1 strain. The isolation of viruses and the genetic characteristics of the he magglutinin（HA） gene were also performed. Results in the epidemiologic investigation indicated that these two cases were in family clusters. The first case appeared ＂white lung＂in X-ray examination 3 days after pneumonia and died 8 days later, while the other case survived without consolidation change over the whole area of lungs. The detection of the H5N1 gene in the throat swab specimens of both cases was proved to be positive with the H5N1 gene testing and the isolated viruses were identified to be the H5 serotype. The genetic homology of HA between these 2 isolates was 100% and those with viruses isolated from Anhui, Zhejiang and Jiangsu provinces were 99.0% 98.9% and 98.7% respectively. As demonstrated by analysis on the phylogenetic tree these 2 isolates they belonged to the 2. 3. 4 subgroup of H5N1 Clade Ⅱ genotype. The receptor specificity connecting peptides between HA1 and HA2 were still proved to be avian influenza origin. It is concluded from the above observations that these 2 cases were confirmed to be infected by H5N1 virus in a family cluster. The limited pattern of H5N1 virus transmission from one case to another ease only happened between direct relatives and the HA gene of these two related strains are found to be of avian influenza origin lacking ability of large scale human to human transmission.

关 键 词：高致病性禽流感 H5N1 家庭聚集性 基因特征 

分 类 号：R183.3[医药卫生—流行病学]