Stary A, Tomazic-Allen S, Choueiri B, Burczak J, Steyrer K, Lee H
Outpatients' Centre for Diagnosis of Infectious Venero-Dermatological Diseases, Vienna, Austria.
Sex Transm Dis. 1996 Mar-Apr;23(2):97-102. doi: 10.1097/00007435-199603000-00002.
To evaluate the performance of DNA amplification-based tests for the diagnosis of urethral chlamydia infection from the urine of asymptomatic young men.
First-void urine was analyzed by two amplified DNA technologies, the ligase chain reaction (LCR), the polymerase chain reaction (PCR), and enzyme immunoassay (EIA). Specimens yielding discrepant results were subjected to retesting using either the original or a newly processed sample, and for evaluation of truly infected persons they were analyzed by the direct fluorescence antibody assay and by a second LCR directed against a segment of the gene encoding for the major outer membrane protein of Chlamydia trachomatis.
The military hospital in which military recruits underwent medical examination before departing for a United Nations mission.
Asymptomatic military recruits (705 young men) were screened between January and May 1994. In addition to providing urine specimens, the recruits completed questionnaires concerning previous genital infections and number of sexual partners.
Overall prevalence of urethral chlamydia infection in the study group was 4.1% (29/705), as determined by confirmed results in all tests collectively. The performance of the DNA amplification methods was markedly better than that of the EIA antigen detection methods. Using an expanded gold standard, the sensitivity of the LCx assay was 93.1% (27/29) compared to 62.1% (18/29) by the PCR assay Amplicor and 37.9% (11/29) by EIA. Repeat testing after freezing and thawing increased the number of positive PCR results to equal the number of positive LCR results. There were three false-positive Amplicor results and no false-positive LCR results.
The LCx assay performed better than the Amplicor assay and appears reliable for urine testing. The low sensitivity of the Amplicor assay requires further evaluation of possible inhibitors of PCR in fresh specimens. It was found that freezing and thawing the specimens before testing enhanced the performance of PCR.
评估基于DNA扩增的检测方法对无症状青年男性尿液中尿道衣原体感染的诊断性能。
采用两种扩增DNA技术，即连接酶链反应（LCR）、聚合酶链反应（PCR）以及酶免疫测定（EIA）对首次晨尿进行分析。对结果不一致的标本，使用原始样本或新处理的样本进行重新检测，为评估真正感染的个体，采用直接荧光抗体检测以及针对沙眼衣原体主要外膜蛋白编码基因片段的第二种LCR进行分析。
新兵在前往联合国执行任务前接受体检的军队医院。
1994年1月至5月期间对705名无症状新兵进行了筛查。新兵除提供尿液标本外，还填写了有关既往生殖器感染及性伴侣数量的问卷。
通过所有检测的综合确诊结果确定，研究组尿道衣原体感染的总体患病率为4.1%（29/705）。DNA扩增方法的性能明显优于EIA抗原检测方法。采用扩展金标准，LCx检测的灵敏度为93.1%（27/29），相比之下，Amplicor PCR检测为62.1%（18/29），EIA检测为37.9%（11/29）。冻融后重复检测使PCR阳性结果数量增加至与LCR阳性结果数量相等。有3例假阳性Amplicor结果，无LCR假阳性结果。
LCx检测的性能优于Amplicor检测，对尿液检测似乎可靠。Amplicor检测的低灵敏度需要进一步评估新鲜标本中可能存在的PCR抑制剂。发现检测前冻融标本可提高PCR的性能。
