INCIDENCE AND RISK-FACTORS FOR ACQUISITION OF SEXUALLY-TRANSMITTED DISEASES IN HETEROSEXUALS WITH MULTIPLE PARTNERS

Background and objectives: The incidence of four STDs that are mainly transmitted during vaginal intercourse, and risk factors for acquisiti on during follow-up were studied in a cohort of heterosexuals with mul tiple partners in Amsterdam, the Netherlands. These heterosexuals with 15 different sexual partners in the preceding 6 months were recruited from an STD clinic and participated voluntarily in a longitudinal HIV study between 1987 and 1991. Study design: Using survival techniques, the authors analyzed data on general characteristics, sexual behavior , reported and diagnosed STDs of 155 men and 234 women participating a t least twice in the HIV study and returning regularly. Results: The m ajority of women were prostitutes and the majority of men were clients of prostitutes. For men and women, the 2-year cumulative incidence we re 2.7% (95% confidence interval [95%CI] 0.9-8.3) and 0.8% (95%CI 0.1- 5.8), respectively, for syphilis, 8.5% (95%CI 3.9-18.0) and 5.3% (95%C I 2.6-10.8) for gonorrhea, 20.2% (95%CI 12.5-31.9) and 31.9% (95%CI 23 .7-42.2) for Chlamydia trachomatis infection, and 24.5% (95%CI 17.3-34 .2) for trichomoniasis (examination in women only). Among men, STD(s) diagnosed at entry was found to be an independent predictor of infecti on with any of these STDs during follow-up (relative hazard (RH) = 2.5 8, 95%CI 1.18-5.64). Among women, risk factors were age less than or e qual to 25 years (RH = 1.82, 95%CI 1.13-2.19) and current report of co mmercial unprotected vaginal contacts (RH = 2.19, 95%CI 1.11-4.13). Am ong women, trichomoniasis during follow-up was predicted by current re port of commercial contacts (RH = 2.59, 95%CI 1.16-5.79). C. trachomat is infection in women was associated with native country outside the N etherlands (RH = 2.47, 95%CI 1.38-4.43), reported history of STDs in t he 4 months before the study (RH = 2.92, 95%CI 1.39-6.14) and age less than or equal to 25 years (RH = 1.90, 95%CI 1.06-3.40). Conclusions: This study shows that STDs were common among this group of heterosexua ls, despite regularly participating in the HIV study in which consiste nt condom use was promoted. Prevention efforts should be intensified f or men and women having commercial sexual contacts, young women, and i ndividuals with a history of STDs.