Sociodemography of genital co-infection with Neisseria gonorrhoeae and Chlamydia trachomatis in Coventry, UK

Abstract

While genital co-infection with Neisseria gonorrhoeae and Chlamydia trachomatis in the same individual is relatively common, little is known about the characteristics of individuals co-infected with both pathogens. We describe the sociodemographic and geographic characteristics of those with genital co-infection with N. gonorrhoeae and C. trachomatis. We reviewed the case-notes of all patients presenting with co-infection between March 1989 and February 2000. Incidence rates were calculated for those aged 15–64 living in the 18 different electoral wards of the city and subjects were assigned a Townsend deprivation score based on residence. A total of 332 cases of co-infection were included over the study period (overall mean annual incidence rate 16.1 [95% confidence interval [CI] 9.9–22.3]/100,000). The infection rate was significantly higher in those of black ethnicity (rate: 82.6/105, relative rate 5.81, 95% CI [4.03–8.38], P=0.0001) than in those of other ethnicities. The highest incidence was noted in men aged 20–24 ( n=81, 45.6%) and in women aged 15–19 ( n=66, 45.2%) years, living in the most deprived area of the city. After controlling for year of diagnosis, those aged 25–64 years had significantly lower incidence rates (0.13 [0.10–0.17], P=0.0001, Poisson regression) than those aged <20 years. Increased incidence rates were also associated with high deprivation scores. There is a complex interaction between age, sex, ethnicity, geographic distribution, social deprivation and the risk of acquiring genital co-infection with N. gonorrhoeae and C. trachomatis. This study may help to identify the geographic areas of high incidence of sexually transmitted diseases in Coventry, and could be used as the baseline to measure the need for subsequent interventions.