评价荧光定量逆转录-聚合酶链反应和酶联免疫吸附试验方法在麻疹监测中的价值

Evaluation the Value of Real-time Fluorescent Reverse Transcription Polymerase Chain Reaction and Enzyme-linked Immunosorbent Assay in Measles Surveillance

目的评价荧光定量逆转录-聚合酶链反应（real-time RT-PCR）和酶联免疫吸附试验（ELISA）方法在麻疹病毒感染病例中的诊断价值。方法分析2014年天津市麻疹监测信息报告管理系统报告数据,运用χ~2检验（Chi-square Test）、配对Mc Nemar检验和效度分析,比较2种方法的判定价值。结果 171例麻疹疑似病例同时采集了血清和干血片标本,ELISA法检测两种标本IgM抗体阳性率分别为53.22%和49.71%,差异无统计学意义（χ~2=3.60,P=0.06）,两种标本ELISA法检测一致率为94.15%。2 512例麻疹确诊病例中,2 439例采集了血标本,ELISA法检测IgM抗体阳性率为76.38%;871例采集了咽拭子,real-time RT-PCR检测核酸阳性率为86.68%。咽拭子采样间隔在3天内的real-time RT-PCR核酸阳性率达到91.14%,3天后的阳性率只有66.26%（χ~2=72.46,P〈0.01）。血标本采样间隔在3天内的ELISA IgM抗体阳性率为71.47%,3天后达到94.14%（χ~2=118.06,P〈0.01）。检验效度分析,ELISA方法灵敏度为71.60%,特异度为85.29%,约登指数为0.57。real-time RT-PCR方法灵敏度为99.60%,特异度为67.65%,约登指数为0.67。结论 real-time RT-PCR方法更敏感,适合发病早期诊断,ELISA方法更适合发病中后期诊断。

Objective To evaluate the value of real-time fluorescent reverse transcription polymerase chain reaction （real-time RT-PCR） and enzyme-linked immunosorbent assay （ELiSA） in diagnosis of measles. Methods Data from Measles Monitoring Information System of Tianjin in 2014 were analyzed, and Chi-square test, paired McNemar test, and validity analysis were used to compare the two detection methods. Results Serum and dried blood spots specimens were collected from 171 suspected measles cases, and IgM antibody positive rates by ELISA in these two kinds of specimens were 53.22% and 49.71% , respectively, with no significant difference （x^2 = 3.60, P = 0. 06） ahd a consistent rate of 94. 15% between the two results. In 2 512 confirmed measles cases, 2 439 cases had blood specimen, in which IgM antibody positive rate by ELISA was 76.38%. 871 cases had swab specimen, in which the nucleic acid positive rate by real-time RT-PCR was 86.68%. When swab samples were collected within 3 days of rash onset, the nucleic acid positive rate was 91.14%, while it was only 66.26% when samples were collected after 3 days （x^2 = 72.46, P 〈 0.01 ）. By ELISA, IgM antibody positive rate was 71.47% for blood specimen collected within 3 days of rash onset, and 94. 14% for specimens collected after 3 days of rash onset （x^2 = 118.06, P 〈0.01 ）. Validity analysis for ELISA showed a sensitivity of 71.60%, a specificity of 85.29%, and Youden＇s index of 0.57. For real-time RT-PCR, the analysis showed a sensitivity of 99.60%, a specificity of 67.65%, and Youden＇s index of 0.67. Conclusions Real-time RT-PCR was more sensitive and suitable for early diagnosis. ELISA was more suitable for middle-late diagnosis.