Direct detection of Chlamydia trachomatis in urine specimens from symptomatic and asymptomatic men by using a rapid polymerase chain reaction assay

Abstract

Screening for Chlamydia trachomatis infection in men has traditionally been limited to men who present with urethral symptoms, thereby limiting the detection of asymptomatic chlamydia infection in men. In order to effectively screen both symptomatic and asymptomatic men, we evaluated a newly developed polymerase chain reaction (PCR) assay, Amplicor C. trachomatis, from Roche Molecular Systems for the detection of C. trachomatis in urine specimens in comparison with urethral culture. A total of 530 male urine specimens were collected from 322 symptomatic and 208 asymptomatic men attending two sexually transmitted disease clinics in Baltimore, Md. The prevalence of C. trachomatis by culture was 9.8% (10.6% in symptomatic men and 8.2% in asymptomatic men). Compared with culture, the sensitivity of the PCR was 92.8%, the specificity was 94.7%, the positive predictive value was 68.4%, and the negative predictive value was 99.1%. Discrepant results between culture and PCR were further analyzed by direct fluorescent-antibody staining of elementary bodies in urine sediment and in culture transport vials and by major outer membrane protein PCR of transport media for specimens with negative culture. The revised sensitivity and specificity of PCR for urine were 95.0 and 99.8%, respectively, and the positive and negative predictive values were 98.7 and 99.1%, respectively. The sensitivity of culture compared with PCR and/or direct fluorescent-antibody staining was 68.4%. These results indicate that the PCR assay is a highly sensitive and specific assay for the detection of C. trachomatis in male urine specimens and provides a noninvasive technique for routine screening of chlamydia infection in both symptomatic and asymptomatic men.