Gonorrhoea reinfection in heterosexual STD clinic attendees: longitudinal analysis of risks for first reinfection.

OBJECTIVES: Gonorrhoea is associated with adverse reproductive health outcomes, including pelvic inflammatory disease and increased HIV transmission. Our objective was to determine the association of demographic factors, sexual risk behaviours, and drug use with incident gonorrhoea reinfection among public STD clinic clients.
METHODS: A retrospective cohort study conducted from January 1994 through October 1998, of heterosexual public STD clinic attendees age >/=12 years having at least one gonorrhoea infection in Baltimore, MD. The outcome was first incident gonorrhoea reinfection over a maximum 4.8 years, compared in STD clinic clients with or without sexual risk behaviours and drug use at initial gonorrhoea infection.
RESULTS: 910 reinfections occurred among 8327 individuals and 21 246 person years of observation, for an overall incidence of 4.28 reinfections per 100 person years (95% CI 4.03 to 4.53). Median time to reinfection was 1.00 year (95% CI 0.91 to 1.07 years). In multivariate Cox regression, increased reinfection risk was associated with male sex, younger age, greater number of recent sex partners, and having a sex partner who is a commercial sex worker. Injection drug use and coming to the clinic as an STD contact were protective. Among risk factors that differed significantly between men and women, injection drug use was protective of reinfection in men, and "any" condom use was a risk factor for reinfection in women
CONCLUSIONS: Reinfection represents a significant proportion of STD clinic visits for gonorrhoea. Prevention counselling and routine screening for patients at high risk for reinfection should be considered to maximally reduce transmission and resource utilisation.