Diagnosis of Male Chlamydia trachomatis Urethritis by Polymerase Chain Reaction

Abstract

A quick and highly sensitive diagnostic test would be valuable in the diagnosis of Chlamydia trachomatis. We compared a new polymerase chain reaction (PCR) technique to Chlamydiazyme (Abbott, North Chicago, IL) in the detection of male chlamydial urethritis, and evaluated the performance of PCR on urine samples. Urethral samples for analysis by PCR and Chlamydiazyme were obtained from 474 unselected patients attending a sexually transmitted diseases (STD) clinic. Urine samples were analyzed by PCR from 362 of these patients. Twenty seven (5.7%) urethral samples were positive by Chlamydiazyme, while 64 (13.5%) were positive by PCR. After resolution of discrepant results, the sensitivity of PCR on urethral swabs was 98.4% and the specificity was 99.0%, with positive and negative predictive values of 93.8% and 99.8%, respectively. These same measures for Chlamydiazyme were 43.5%, 100%, 100%, and 92.2%, respectively. The sensitivity of PCR on urine samples was 87.1%, the specificity was 98.0%, and the positive and negative predictive values were 90.0% and 97.4%, respectively. This PCR test is more sensitive than Chlamydiazyme in detecting male urethral chlamydial infections in an STD clinic population, and appears to be equally efficacious on urethral swabs and urine samples.