The influence of sexual and social factors on the risk of Chlamydia trachomatis infections: a population-based serologic study.
BACKGROUND: Genital chlamydia infections often are asymptomatic, which promotes their spread in the population. In women, the possible consequences of infection are pelvic inflammatory disease and infertility. Most studies on the prevalence of Chlamydia trachomatis have been based on clinical series, and prevalences tend to vary with the clinical setting. Few seroepidemiologic studies have emerged from industrialized countries. GOAL OF THIS STUDY: To assess the prevalence of Chlamydia trachomatis using culture and serology, and its relationship with possible risk factors. STUDY DESIGN: This was a population-based study involving completion of a self-administered questionnaire, analysis of cervical samples for Chlamydia trachomatis, and serologic tests for Chlamydia trachomatis antibodies. RESULTS: The prevalence of Chlamydia trachomatis infection was 2.7%, and the seroprevalence was 24.7% among the sexually active women. Seropositivity was correlated with sexual behavior variables, and the incidence of serologic cross-reactivity with respiratory infections (strain TWAR) was low. Multivariate logistic regression analysis showed the number of sexual partners, age at first coitus, history of therapeutic abortion, and previous pelvic inflammatory disease to be independently correlated with seropositivity. CONCLUSION: Early sexual experience and multiple lifetime sexual partners are independent risk factors for Chlamydia trachomatis infection.