The overall goal of the San Antonio STI TM CRC is to develop test STI preventive diagnostic and and strategies in heterosexual Mexican- and African-American couples. In the process of accomplishing our Aims, we serve as the recruitment and interview data (behavioral and clinical) collection arm of the CRC. Having biologic specimens and behavioral data (e.g., number of partners and whether took all medication) from both partners allows collaboration with all projects, e.g., to gain greater insight into organism homology, concordance of symptom severity and treatment response. In 2 prior randomized studies our female-alone intervention was associated with approximately 40% reduction in CT and/or GC rates. We believe a 55% reduction can be attained by intervening on male partners. This project focuses on assessing effects of a dual prevention intervention (male and female partners receiving separate intervention), compared to controls (receive counseling alone) and female-alone intervention; primary outcomes are female (Aim 1) and male (Aim 2) CT and/or GC infection rates; secondav outcomes are sexual and health-seeking behaviors. Other aims are to compare intervention effects (infection and behaviors) across genders and ethnic groups; assess effects of both interventions on ARRM constructs and psychological states and how these impact infection and behavior; use data from both partners to better understand the complex relationship between behavior and infection; assess the effects of both interventions on couple longevity and satisfaction and the extent to which these impact outcomes; better understand the impact of psychosocial factors on behavior; and assess the acceptability of hypothetical microbicides and STI vaccination. A prospective, stratified (ethnicity and substance use) random design, with 6 and 12 month followup will be used. 500 couples (female ages 15-45), 175 controls, 175 female-alone, and 125 dual intervention, wilt be recruited from citywide public health clinics. Allowing for 20% attrition, we should have 400 couples at study completion, allowing us 91% power to test the dual, and 81% power to test the female-alone (40% effect size) intervention. All women will have a current STI and an ongoing relationship with a non-abusive partner whom they are willing to invite to the study. Final analyses will focus on logistic regression to compare intervention efficacy among study groups (infection and behaviors) and to assess possible interactions by gender and ethnicity.