Clinical characteristics of Chlamydia trachomatis infections in a general outpatient department of obstetrics and gynaecology in the Netherlands.

OBJECTIVE Evaluation of prevalence and risk factors of Chlamydia trachomatis infections in an outpatient obstetric and gynaecological population. METHODS A prospective, observational study was performed at an inner city hospital in The Hague, Netherlands. 1368 women attending the outpatient department of obstetrics and gynaecology participated in the study. For detection of C trachomatis infections we used amplification of CT rRNA in urine samples (Gen Probe/AMPLIFIED-CT) and DNA probe for detection of CT rRNA from a urethral, endocervical and anal swab (Gen Probe/PACE 2). RESULTS The overall prevalence of C trachomatis infections in our general obstetric and gynaecological population was 4.5%. The prevalence in women under 30 years of age was 8. 1%. We found age and postcoital bleeding to be significant risk factors. We did not find significant differences between women from different ethnic origin or between women using different kinds of contraceptives. 12 (19.4%) patients with C trachomatis infections were found positive by urine test only, and 15 (24.2%) only by DNA probe. CONCLUSIONS Age is the most important risk factor in our population (overall prevalence 4.5%, prevalence in women under 20 years of age 15.8%). Analyses of urine and of endocervical specimens are complementary for the determination of the prevalence of C trachomatis infections in women. Cost effectiveness analysis is needed to determine to what extent age based screening and/or antibiotic prophylaxis before intrauterine manipulations is indicated.