The NIMH Collaborative HIV/STD Prevention Trial is a randomized study designed to test a community- level popular opinion leader (CPOL) preventive intervention in five international sites. UCSF collaborates with UCLA and Cayetano Heredia University in Lima to test the intervention in Peru. UCSF, UCLA and the Universidad Peruana Cayetano Heredia (UPCH) are collaborating to test this intervention among men and women in lower income neighborhoods. The study is being conducted in Lima, Trujillo and Chiclayo, three coastal cities in Peru.

The aims of the study are:

• Assess prevalence and incidence of HIV and STDs and risk behaviors in the target populations aged 18- 40 in 20 low-income neighborhoods.

• Design and implement a community-level prevention intervention in 10 of those neighborhoods by training and monitoring CPOLS for a period of two years to promote HIV and STDs risk reduction. The intervention consisted of training and motivating CPOLs for three marginal population segments to disseminate prevention messages among their peers.

• Assess the impact of the intervention in intervention neighborhoods compared to control sites.