ENZYME-IMMUNOASSAY AND DIRECT IMMUNOFLUORESCENCE FOR DETECTION OF CHLAMYDIA-TRACHOMATIS ANTIGEN IN MALE FIRST-VOID URINE

First-void urine specimens, collected from 309 military recruits, 246 male adolescent gymnasium students and 194 patients consulting venerea l disease clinics, were studied for the presence of Chlamydia trachoma tis with the use of antigen detection tests two enzyme immunoassays (E IA) and a direct immunofluorescence test (DIF; Syva MicroTrak). Urethr al swabs were collected when discrepancies between the EIA and DIF tes ts were detected. The patient was regarded as positive when the cultur e result was positive or when two antigen detection tests corraborated one another. The Syva MicroTrak EIA and DIF tests were more sensitive than the Orion EIA, i.e. 98.5%, 99.2% and 74%, respectively. This was true when testing both low- and high-risk groups, with a prevalence o f chlamydial infection ranging from 0.4% to 58.6%. All three tests wer e highly specific. The positive predictive values for the Syva MicroTr ak EIA, the DIF and the Orion EIA were 99.2%, 100% and 100%, respectiv ely and the negative predictive values 99.8%, 99.8% and 94.8%, respect ively.