Abstract

AIMS: To evaluate demographic characteristics of women terminating their pregnancy for sentinel surveillance of Chlamydia trachomatis infection and to report changing prevalences of C trachomatis over time within this study population. DESIGN: Screening for C trachomatis in women seeking induced abortion was introduced in 1984 at the Department of Gynecology, Regional Hospital, Trondheim, Norway. Over the study years our department has used a precoded medical record covering sociodemographic, medically relevant data, also recording outcome of the C trachomatis test. Throughout the study the Department of Microbiology applied cell culture, enzyme immunoassay, and, during the most recent years a nucleic acid test to identify C trachomatis. STATISTICAL METHODS: Chi square test for linear trend and unconditional logistic regression. RESULTS: Over the study period, women having induced abortion were characterised by being most often single and more often at younger age. The overall age-adjusted prevalence of C trachomatis declined from 9.2% in 1985 to 3.6% in 1995, the major decline occurring from 1987 to 1991, and affected all age-groups simultaneously. There was a 60% decrease in odds ratio of having a C trachomatis infection from 1985 to 1991, and the crude and the adjusted odds ratios did not differ for any year examined. CONCLUSION: Women deciding on pregnancy termination have demographic characteristics that identify high-risk groups for C trachomatis infection. Despite these characteristics, which were relatively constant over the study period, the study population changed from being a high- to a low-prevalence population of C trachomatis.