Beginning in 1981 when the first case of HIV was diagnosed, the HIV and AIDs epidemic has dramatically altered the social, cultural, economic, political and demographic landscape worldwide. Understanding the drivers and the implications of this epidemic of individuals, families, communities and countries requires insight into the myriad of biological, socio-cultural and political factors that shape individual knowledge and behavior, access to preventive and treatment modalities, as well as the political and international responses to the epidemic. The purpose of this course is to provide an overview of the social and behavioral factors that influence the transmission and prevention of HIV and AIDs worldwide. Topics to be covered include the natural history and epidemiology of the AIDS virus, the mechanisms of transmission, high risk and vulnerable populations, social determinants of risk and vulnerability, theoretical foundations for HIV prevention programs, primary and secondary HIV prevention strategies, treatment of HIV and AIDS, and implications of HIV and AIDS for individuals, families, communities and countries.