Comparative epidemiology of heterosexual gonococcal and chlamydial networks: implications for transmission patterns.

OBJECTIVE: Networks of sex-partner interaction affect differential risk of acquiring sexually transmitted infections. The authors evaluated sociodemographic and behavioral factors that correlated with membership in networks of gonococcal and chlamydial transmission.
METHODS: Face-to-face interviews were conducted with 127 patients with gonorrhea and 184 patients with chlamydia (index cases) and their named sex partners, as well as the partners of infected partners. Detailed information was obtained regarding demographic, behavioral, and sexual-history characteristics of all respondents.
RESULTS: Gonococcal-network members differed significantly from chlamydial-network members in a number of demographic variables, including race or ethnicity, education, and unemployment status. Gonococcal-network members were more likely to report past history of crack-cocaine use, sexual assault, and having been in jail. Gonococcal-network members also reported having more sex partners during the past 1 year and 3 months than did chlamydial-network members. Gonococcal and chlamydial mixing matrices demonstrated assortativeness for sex partner selection by race or ethnicity but not by sexual activity level, and no systematic differences between networks were noted. Gonococcal networks were larger than chlamydial networks.
CONCLUSIONS: Network analyses of gonococcal and chlamydial infections demonstrated significant differences in sociodemographic and behavioral variables. Further research is required to delineate specific predictors of network membership among persons at risk for sexually transmitted infections.