我国首例孕妇感染高致病性禽流感(H5N1)的病原学研究

对2005年11月8日安徽省铜陵市人民医院报告的一例孕妇不明原因肺炎病例的死亡病因进行研究。采集病人的气管吸出物及血液标本,用RT-PCR和Real-ti me PCR方法检测流感病毒A/M、A/H5N1、A/H7N7、A/H9N1亚型特异性核苷酸片段;气管吸出物接种SPF鸡胚进行病毒分离,并对分离物进行鉴定和序列测定及分析;利用血凝抑制试验检测血清标本抗体。结果表明病人气管吸出物可以检测到甲型流感病毒M片段及H5亚型的特异性HA基因。2005年11月9日采集的血清标本用Real-ti me PCR检测到甲型流感病毒M基因。从病人的气管吸出物中分离到H5N1病毒(A/Anhui/1/2005),对病毒的HA基因序列结果进行分析表明病毒是禽源的,其主要依据是受体结合位点第226~228位氨基酸位点(QSG)为禽流感病毒所特异,HA受体连接肽仍为9个碱性氨基酸(LRERRRKRP);基因进化树分析显示,HA基因与禽源病毒进化距离接近。发病后7、8、9d的血清H5N1禽流感病毒HI抗体小于20。对该病例的病原学研究证明,该病例为H5N1禽流感感染病例。

The Firstly Confirmed Pregnant Woman Case of Avian Influenza A (H5N1) by Etiological Research in China

To investigate the cause of death of a pregnant woman with undefined pneumonia reported from the People's Hospital of Tongling City in Anhui Province on November 8,2005,the patient's tracheal aspirates and serum samples were collected and tested by RT-PCR and Real-time PCR to detect viral nucleic acids of HA of A/H5N1,A/H7N7,A/H9N1 and A/M.Tracheal aspirates were inoculated into special pathogen free(SPF) embryonated eggs for cultivation and identification of virus.The HA gene of the virus was sequenced and analyzed.Serum samples were tested by HI assay to detect antibody of H5N1.The results showed that HA gene of A/H5N1 virus and A/M were positive in tracheal aspirates by both PCR tests.The serum sample collected on Nov.9 was A/M gene positive by Real-time PCR.The analysis of HA gene of A/AnHui/1/2005 sequence showed that the receptor specificity and the connecting peptide between HA1 and HA2 were still avian influenza origin.The HI antibody of H5N1 was negative at 7th,8th,9th d of disease onset.This undefined pneumonia case was confirmed as the first pregnant woman case of avian influenza(H5N1) virus infection by etiology in the mainland of China.