Detection of Chlamydia trachomatis in first‐void urine collected from men and women attending a venereal clinic

Abstract

Cervical, urethral and first-void urine (FVU) specimens from 196 men and 245 women attending a venereal outpatient clinic were studied by culture and a commercial enzyme immunoassay (EIA) (CHLAMYDIAZYME). Confirmatory chlamydial testing by a direct fluorescence assay (DFA) (MICROTRAK) was performed on the sediments of the positive EIA samples from culture-negative patients. Chlamydia trachomatis was isolated from 11% of the men and 12% of the women. Of the women, 67% were positive in both sampling sites and 33% in the cervix only. No further cases were found when a female urethral swab was cultured. All the chlamydia-positive urine samples were obtained from women who were positive in the urethra. The denominator used to calculate sensitivities was the combination of patients with culture- and EIA-positive results which could be confirmed by DFA. The sensitivity of our culture method was 85% for men and 77% for women. In men, the sensitivity of EIA was greater on urine than on urethral specimens (77% vs 62%; p less than 0.1). In women, the sensitivity of EIA on urine was significantly poorer than that on cervical specimens (54% vs 85%, p less than 0.001). The specificity of EIA ranged between 94 and 100%. Our study suggests that it may be worth using FVU in a trial for the diagnosis of genital chlamydial infections in symptomatic men, but not in symptomatic women.