Screening for Chlamydia trachomatis in military personnel by urine testing

In order to determine the infection rate of Chlamydia trachomatis in young males in Austria an epidemiological study was performed on 335 male Austrian soldiers attending the military hospital for a health check-up procedure. Three hundred twenty-nine (98.2%) of the screened males were clinically asymptomatic. Chlamydial diagnosis was established by testing first catch urine (FCU). Urine sediment was tested by an enzyme immunosorbent assay (EIA) and by a direct immunofluorescent test (DIF test). Positive results in both tests were defined "true positives." In 41 (12.2%) of all the 335 soldiers a genital chlamydial infection could be demonstrated by a positive result of the sediment of the FCU in both tests. 93% of the positive results in the DIF test could be confirmed by the EIA whereas only 77% of the positive EIA tests were also positive in the DIF test. Data on genital symptoms and the history of sexually transmitted diseases (STDs) as well as information about sexual relationships were available from all persons included in the study and did not differ between chlamydia positive and negative ones. The study demonstrates a high infection rate with C. trachomatis in mostly asymptomatic young males when using FCU for chlamydial diagnosis. Due to the discrepancy between the EIA and the DIF test, positive results of the sediment of FCU in the EIA test should be confirmed by the DIF test to eliminate false positive cases.