OBJECTIVE: To discuss the occurrence of genital chlamydia in developed countries and review the literature assessing the potential risk factors for this sexually transmitted disease.
DATA SOURCES: A MEDLINE search was performed for all English citations from 1985 to 2000 that contain the keywords “Chlamydia trachomatis”, “chlamydial infections”, “risk factors” and “sex behaviour”. All relevant references cited in articles that were obtained from the search were also included.
DATA EXTRACTION: All articles obtained from the above sources were examined, and were included in the review if they met the following criteria: primary study examining sociodemographic or behavioural risk factors associated with genital chlamydial infection using multivariate analysis; study subjects 12 years of age and older; and study setting in a developed country.
DATA SYNTHESIS AND CONCLUSIONS: Genital chlamydial infection has become the most commonly reported bacterial infection in North America over the past decade. Thirty-eight cross-sectional studies and six cohort studies were included in the present review. Most studies demonstrated that young men and women are at higher risk of being infected with chlamydia than older subjects. Chlamydia seems to be found in a diverse group of people, and unlike gonorrhea, is not concentrated in low income, minority core groups with high rates of partner change. However, a number of studies have shown that communities with well-established control programs are beginning to demonstrate this pattern. There is no clear evidence that chlamydia is associated with type of partners, contraceptive use, or age at first intercourse. Future research should follow this sexually transmitted disease as it evolves through the epidemiological stages to ensure that preventive and treatment services are reaching those people who are most likely to be infected.