The NIMH Collaborative HIV/STD Prevention Trial is a two-arm randomized, community-level trial being conducted in five countries--China, India, Peru, Russia, and Zimbabwe. It is the first international test of a community-level prevention program and is based on the theory of diffusion of innovation utilizing Community Public Opinion Leaders (C-POLs). In this intervention model, popular opinion leaders within a high-risk population are systematically identified, recruited, trained, and engaged to communicate risk reduction messages to friends and acquaintances also in the target population. Based on a set of ethnographic studies conducted over 18 months and a series of epidemiological studies with over 9000 participants in the five countries, an assessment and the C-POL intervention have been culturally adapted, piloted and mounted in randomly-chosen venues in each country. In Russia, the study's target population is young adults who attend vocational trade schools in St. Petersburg, and the study's venues where assessment and intervention activities take place are 24 slum-like "dormitories" that house these trade school students. Epidemiological studies conducted in these venues established high rates of unprotected sex and prevalent STDs. The C-POL intervention is being carried out in the 12 Russia site dormitories randomized to the intervention condition. The intervention's efficacy in reducing self-reported behavioral risk with non-spousal partners and incident sexually transmitted diseases is being assessed based on a baseline, 12- and 24- month interviews and collection of biological specimens that are tested for STDs and HIV. After conducting the 24-month assessment, the intervention will be provided in the comparison venues. This proposal requests three years of funding to complete the randomized controlled trial in each site; the extended period is requested because of the extra time required at the initiation of the study to conduct multiple epidemiological and ethnographic studies to ensure cross-site comparability and within-site validity to all assessments, intervention, and data collection and reporting processes. The results of this trial should provide the first documentation and evaluation of the portability and adaptability of interventions cross nationally and cross-culturally and is being designed and implemented to be realistic and feasible for replication and dissemination. [unreadable] [unreadable]