Clarke L M, Sierra M F, Daidone B J, Lopez N, Covino J M, McCormack W M
Department of Pathology, State University of New York Health Science Center, Brooklyn 11203.
J Clin Microbiol. 1993 Apr;31(4):968-71. doi: 10.1128/jcm.31.4.968-971.1993.
Culture is currently considered the "gold standard" for detecting Chlamydia trachomatis infections. We evaluated the Syva MicroTrak enzyme immunoassay (EIA) and Gen-Probe PACE 2 tests, which detect chlamydial antigens and rRNA, respectively. These assays were compared with each other and with culture for the detection of C. trachomatis in cervical specimens obtained from 217 women attending a clinic for sexually transmitted diseases. The prevalence of infection was 22.1% by culture. The sensitivity, specificity, and positive and negative predictive values were 79.2, 98.2, 92.6, and 94.3%, respectively, for EIA. For PACE 2, the respective values were 77.1, 97.6, 90.1, and 93.7%. After corrections for two false-negative cultures, the sensitivities and specificities were 80 and 99.4%, respectively, for the EIA and 78 and 98.8%, respectively, for the probe assay. Quantitative evaluation of the results showed that false-negative results with either assay were associated with cultures that had low inclusion counts or were negative without subpassage. Analysis of nonculture results revealed that 2.3% of the EIA results and 4.6% of the probe assay results were within +/- 30% of the respective assay cutoff values. These included four false-negative (one EIA and three probe) and two false-positive (one EIA and one probe) results. The Syva MicroTrak EIA and the Gen-Probe PACE 2 assay are comparable to but significantly less sensitive than culture. Use of a grey zone may help identify the need for repeat or confirmatory testing.
目前，培养法被认为是检测沙眼衣原体感染的“金标准”。我们评估了Syva MicroTrak酶免疫测定法（EIA）和Gen-Probe PACE 2检测法，它们分别检测衣原体抗原和rRNA。将这些检测方法相互比较，并与培养法比较，以检测从一家性传播疾病诊所的217名女性中获取的宫颈标本中的沙眼衣原体。通过培养法检测出的感染率为22.1%。EIA的敏感性、特异性、阳性预测值和阴性预测值分别为79.2%、98.2%、92.6%和94.3%。对于PACE 2，相应的值分别为77.1%、97.6%、90.1%和93.7%。在纠正了两个假阴性培养结果后，EIA的敏感性和特异性分别为80%和99.4%，探针检测法的敏感性和特异性分别为78%和98.8%。结果的定量评估表明，两种检测方法的假阴性结果都与包涵体计数低或未传代即为阴性的培养结果相关。对非培养结果的分析显示，2.3%的EIA结果和4.6%的探针检测结果在各自检测临界值的±30%范围内。这些结果包括4例假阴性（1例假阴性EIA和3例假阴性探针检测）和2例假阳性（1例假阳性EIA和1例假阳性探针检测）结果。Syva MicroTrak EIA和Gen-Probe PACE 2检测法与培养法相当，但敏感性明显低于培养法。使用灰色区域可能有助于确定是否需要重复检测或进行确证检测。
