Detection of Chlamydia trachomatis in first-void urine from men and women as an alternative to swabs

BACKGROUND: Ideally, an effective preventive strategy for the control of Chlamydia trachomatis infection should take into account the following attributes: rapid and simple specimen collection, low cost and noninvasive test processing. Therefore, we compared the performance profile of urine-based detection of C. trachomatis antigen in first-void urine with that of testing urethral and endocervical samples in men and women. MATERIAL AND METHODS: Urethral and endocervical samples and first-void urine from 285 men and 192 women attending the Sexually Transmitted Diseases Outpatient Clinic at the Medical University in Plovdiv, Bulgaria were tested using direct immunofluorescence assay (DFA) (MicroTrak, Syva, Palo Alto, CA, USA). RESULTS: Seventy (25%) of all men tested were positive for C. trachomatis antigen in either urethral or urine samples. 65 men (93%) had both a positive urethral and urine sample, three men (4%) had only a positive urethral sample and two (3%) had only a positive urine sample. Thirty-five women (18%) had C. trachomatis infection. Twenty-six women (74%) had both a positive endocervical and urethral sample, 6 (17%) had only a positive endocervical sample and 3 (8%) had only a positive urethral sample. All women with positive urethral samples tested positive on their urine samples. Two of the women with a negative urethral sample and a positive endocervical sample had a positive urine sample. CONCLUSIONS: These results show that using direct immunofluorescence assay on first-void urine samples is a reliable noninvasive method which can replace urethral swabs in the diagnosis of C. trachomatis infection in symptomatic men. Urine-based strategies are also an acceptable alternative for the diagnosis of C. trachomatis infection in symptomatic women when it is not possible to obtain an urogenital sample.