一起麻疹爆发的血清学和分子生物学研究

STUDY ON SEROLOGY AND MOLECULAR BIOLOGY OF MEASLES OUTBREAK IN SHENZHEN CITY

目的 :了解麻疹爆发的血清学及分子生物学特征。方法 :收集深圳市 2 0 0 2年 3月一起麻疹爆发疫情资料 ,采集急性期血清、咽拭子和尿样本各 6份 ,进行血清学检验 ,并通过 RT- PCR扩增并进行测序及种系分析。结果 :麻疹爆发流行累计发病 14例 ,6份病例血清的麻疹 Ig M抗体阳性率 10 0 % ,患者血清中 Ig G抗体为阴性或滴度很低。通过测序得出麻疹病毒 H基因片断 ,长度为 5 71bp,各毒株同源性在 96 .2 %～ 10 0 %之间。种系分析得出此次爆发的流行株属 H基因组、 H1基因型 ,型内变异为 0 %～ 3.6 % ,与 H2基因变异在 2 .7%～ 4 .3% ;血清抗体实验表明患者血清 Ig G滴度阴性或滴度很低。结论 :麻疹基因变异不会引起新的流行 ,人群抗体水平低下是此次爆发的根本原因。

Objective:To investigate the serology and molecular biology of measles outbreak in Shenzhen city. Methods: Through collecting the datum of measles,founded largely in Shenzhen on March 2002,picking six paired samples of serum,throat-swabs and urinary specimen for seological detection,we got the sequence and phylogenetic analysis by the methord of RT-PCR.Results:Total of 14 cases were found in this measles outbreak.Measles IgM positive rate was 100% in six cases.At the same time,we found that the patients' IgG antibody in serum are either negative or very low .The measles virus gene H section discovered by sequence test is 517bp,and every virus' coisogenetic property is between 96.2%～100%.Phylogenetic analysis clearly proves this kind of popular virus belongs to gene H and gene H1 type,mutation in type is 0~3.6%,and the mutation related to H2 is 2.7～4.3%.Seological experiment indicate the titer is negative or very low in patients' serum.Conclusion:The result shows obviously that gene mutation in measles virus won't cause a new epidemic; the lower level of antibody was the direct reason of measles outbreak.