Sociodemography of genital Chlamydia trachomatis in Coventry, UK, 1992-6

Objective: To describe the sociodemographic and geographic risk factors for incident Chlamydia trachomatis genital infection. Design: Cross sectional retrospective study of cases diagnosed in local gen itourinary clinics. Setting: Coventry, West Midlands, from 1992 to 1996. Subjects: 582 female and 620 male Coventry residents aged 15-64 years diagn osed with one or more episodes of genital Chlamydia trachomatis infection b y enzyme immunoassay. Subjects were assigned a Townsend deprivation score b ased on residence. The denominator population aged 15-64 years was derived from 1991 census data. Results: The mean annual incidence of genital chlamydia was 151 episodes (9 5% CI 140-163) per 100 000 population in men and 138 episodes (95% CI 128-1 49) per 100 000 population in women. Highest subgroup incidence was observe d in 15-19 year old black women (2367 (95% CI 1370-4560) per 100 000), and 20-24 year old black men (1951 (95% CI 1158-3220) per 100 000). In univaria te analyses, the most important risk factor for chlamydia infection in male s was being black (incidence 1377 (95% CI 1137-1652) per 100 000 for black upsilon 133 (95% CI 122-145) per 100 000 for white; RR 10.4-, p<0.0001) and for women was young age (incidence 475 (95% CI 415-540) per 100 000 for ag e group 15-19 years upsilon 52 (95% CI 45-60) per 100 000 for age group 25- 64 years; RR 9.1, p<0.0001). In Poisson regression models of first episodes of genital chlamydia, for both males and females the effect of ethnic grou p could not be fully explained by socioeconomic confounding. There were sig nificant interactions between age and ethnic group for both sexes and betwe en age and level of deprivation for men. Geographical analysis revealed a h igh incidence of genital chlamydia in estates on the edge of the city as we ll as the urban core. Conclusions: There is a complex interaction between geographical location, age, ethnic group, and social deprivation on the risk of acquiring genital Chlamydia trachomatis in Coventry. Better population based data are needed.