EVALUATION OF AN ENZYME-IMMUNOASSAY FOR DETECTION OF CHLAMYDIA-TRACHOMATIS IN URINE OF ASYMPTOMATIC MEN

In a study of 1,486 men attending two sexually transmitted disease cli nics, of whom 891 had no symptoms of urethritis, we compared an enzyme immunoassay (EIA) (Baxter-Bartels, formerly Northumbria AntigEnz) of urine sediment to urethral culture for the detection of Chlamydia trac homatis. C. trachomatis prevalence by culture alone was 7.7% in asympt omatic men and 10.9% in symptomatic men. Discrepant results between EI A of urine and urethral culture were evaluated by direct fluorescent-a ntibody staining (DFA) for elementary bodies in urine sediment or in c ulture transport media. When chlamydial infection was defined as eithe r a positive urethral culture or positive EIA confirmed by DFA, chlamy dia prevalence increased to 8.9% in asymptomatic men and 11.6% in symp tomatic men. The urine EIA sensitivity, specificity, and positive and negative predictive values for chlamydia detection in asymptomatic men were 84.8, 99.3, 91.8, and 98.5%, respectively, with nearly identical results for symptomatic men. The sensitivities of urethral culture al one compared with the combination of urethral culture and urine EIA (w ith DFA confirmation) were 87.3 and 94.3% for asymptomatic and symptom atic men, respectively. The present EIA of urine sediment is both high ly sensitive and specific for the detection of C. trachomatis in asymp tomatic men, thus providing a noninvasive screening method for chlamyd ia infection in asymptomatic men attending sexually transmitted diseas e clinics.