High prevalence and incidence of sexually transmitted diseases in urban adolescent females despite moderate risk behaviors.

To better understand the prevalence, incidence, and risk factors for sexually transmitted diseases (STDs) among female adolescents, a prospective 6-month cohort study was conducted at four teen clinics in a southeastern city. At enrollment, 260 (40%) of 650 sexually active females ages 14-19 years had an STD: chlamydia, 27%; herpes simplex virus type 2 (HSV-2), 14%; gonorrhea, 6%; trichomoniasis, 3%; and hepatitis B, 2%. At follow-up, 112 (23%) of 501 participants had an incident infection: chlamydia, 18%; HSV-2, 4%; gonorrhea, 4%; and trichomoniasis, 3%. At either enrollment or follow-up, 53% had >/=1 STD; of those with 1 lifetime partner, 30% had an STD. Having a new partner (odds ratio [OR], 2.2; 95% confidence interval [CI], 1. 1-4.2) or friends who sell cocaine (OR, 1.6; CI, 1.0-2.6) was independently associated with incident infection. STD incidence and prevalence were extremely high in this population, even in teenagers with only 1 lifetime partner. Individual risk behaviors appeared less important for STD risk than population factors.