DEVELOPMENT AND EVALUATION OF SCREENING STRATEGIES FOR CHLAMYDIA-TRACHOMATIS INFECTIONS IN AN STD CLINIC

Objectives-To identify predictors for Chlamydia trachomatis infection among visitors of an STD clinic in Amsterdam in 1986-1988. To design p redictor-based screening programmes for C trachomatis. To evaluate the chosen screening strategy in 1993. Methods-In 1986-1988, 947 heterose xual men and 648 women participated in the study. A medical history wa s recorded, a physical examination took place and samples were taken f or laboratory diagnostics. Information for 1993 was available from rou tine databases. Results-C trachomatis infections in heterosexual men i n 1986-1988 (prevalence 15.8%) were independently associated with: age under 26 years, being an STD contact, coitarche below 13, last sexual contact with a non-prostitute, (muco)purulent urethral discharge and ten or more leukocytes per microscopic field of urethral smear or urin e. For women (prevalence 21.5%) independent predictors were age under 26, no history of STD, being an STD contact, cervical friability, (muc o)purulent cervical discharge, presence of clue cells and ten or more leukocytes per field of urethral smear. Screening men with one anamnes tic predictor for C trachomatis and ten or more leukocytes in smear or urine (59% of men) would detect 93% of the cases in 1986-1988. For fe males only universal screening proved to be suitable. After the introd uction of a screening strategy in 1989 (universal for women, indicated by urethritis for men), a strong decline was found in the C trachomat is prevalence for all subgroups in 1993, excluding prostitute's client s and Turkish men. Conclusions-In 1993 the overall C trachomatis preva lence had declined among the attendants of the STD clinic. It seems li kely that this fall was caused both by the screening programme and the reduction of risk behaviour.