Sexual Behavior and Sexually Transmitted Infections in a Probability Sample of Adolescents in Baltimore, MD E. Eggleston 1, S.M. Rogers 1, C.F. Turner 2, S.Tan 1, A.M. Roman 3, W.C. Miller 4, M.M. Hobbs 4, E. Erbelding 5, L. Ganapathi 1 1 Research Triangle Institute, Washington DC/RTP, NC; 2 City University of New York, (Queens College & the Graduate Center); 3 University of Massachusetts-Boston, 4 University of North Carolina at Chapel Hill, School of Medicine; 5 Johns Hopkins University, School of Medicine BACKGROUND RESULTS OBJECTIVES CONCLUSIONS Monitors prevalence of undiagnosed STIs (chlamydia, trichomoniasis, gonorrhea) in Baltimore MD. Probability samples of year-olds in households with landline phones. Data sources: 1) telephone audio computer-assisted self interview (T-ACASI); 2) mailed-in urine specimens tested for STIs T-ACASI interviews completed Sept 2006-Aug Report prevalences of sexual activity, risk behaviors and undiagnosed STIs (chlamydia and trichomoniasis) among Baltimore adolescents ages 15-19, from MSSP. Identify correlates of sexual activity and STI. 615 teens aged 15-19, completed T-ACASI interview. 76% (n=467) provided urine specimen, 461 valid for testing. Prevalence of sexual experience among MSSP teens (71%) is higher than Baltimore HS students in YBRS (67%) and U.S. HS students overall (47%) STI rates among Baltimore teens are higher than among U.S. teens: chlamydia: 6% (MSSP) v. 3% (NHANES), trichomoniasis: 4% (MSSP) v. 2% (NHANES). Further research needed to explore racial disparities in measured levels of STI and sexual activity. MONITORING STIs SURVEY PROGRAM (MSSP) Adolescents more vulnerable to STIs than other ages. Surveillance data (CDC) and the population-based NHANES indicate that year-old females have highest reported rates of chlamydia. 47% of U.S. high school students report having had sex (Youth Behavior Risk Survey). METHODS Estimates weighted to account for differing probabilities of selection and postratification adjustment to match 2007 American Community Survey marginals for Baltimore, MD. Bivariate and multivariate logistic regression conducted to measure associations between outcomes (having sexual intercourse and having an STI) and demographic, behavioral and health characteristics. 54% of teens have had more than one lifetime sexual partner Most (64%) had 0 or 1 partner in the past year. Nonwhite teens more likely than whites to have had >1 partner in the past year, 41% v. 13%. 11% of teens report being “hit, shoved or physically hurt by a partner.” Nearly 10% of teens have been incarcerated; 16% have had sexual partner who was incarcerated. Incarceration of partner— but not respondent—more common among nonwhite than white teens (19% v. 4%). Prevalence and Correlates of Sexual Experience 71% of teens have experienced sexual intercourse Nonwhite race, older age (18-19) and low educational level were associated, in multivariate analysis, with odds of being sexually experienced. Risk Factors Prevalence and Correlates of STI 9% of Baltimore teens have an undiagnosed STI (6% Ct, 4%Tv) In multivariate analysis, following factors associated with increased odds of infection: nonwhite race, more than 1 sexual partner in the past year, forced sex, incarceration (of respondent or sexual partner), previous STI diagnosis. Nonwhite teens 10 times more likely than whites to have STI. Contact: