Diagnosis of Chlamydia trachomatis infection in high-risk females with PCR on first void urine.

Recently the polymerase chain reaction (PCR) has been shown to be more sensitive than older methods in detecting Chlamydia trachomatis, when performed on endocervical swabs. A total of 203 high-risk females were enrolled in a comparative study of 3 methods for diagnosing C. trachomatis infections: McCoy cell culture and Amplicor PCR on endocervical swabs, and urine. Thirty-four had positive cultures, 38 positive PCR from cervix and 37 had positive PCR on urine specimens. When discrepancy occurred, the leftover Amplicor specimen was retested by Roche with Amplicor and a primer for the major outer membrane protein (MOMP) gene. In all three tests, 32 were positive. The sensitivity of culture was 87%, 92% in cervical PCR and 95% in urinary PCR. The specificity was 100% in both culture and urinary PCR but 98% in cervical PCR. Amplicor PCR performed on female urine is at least as sensitive and specific as cell culture.