An overview of the global HIV/AIDS epidemic, with a focus on the United States.

The HIV/AIDS epidemic is a global human tragedy, especially in sub-Saharan Africa. The pandemic affects people in the primer of their lives moving from at-risk populations to broader cross-sections of society. There have been more than 47 million adults and children infected since the beginning of the epidemic, and more than 18.8 million people have died. Over 95% of the global total of all AIDS cases are in the developing world, with prevalence among adults at less than 1% in India and Europe, to more than 10% in several African countries. The overwhelming majority of all infections globally are acquired through unprotected sexual intercourse, with at least 70% resulting from heterosexual intercourse. There have been more than 733,374 AIDS cases reported to the Centers for Disease Control and Prevention (CDC) in the US since the beginning of the epidemic, and more than 430,000 deaths. The largest number and proportion of AIDS cases reported have occurred among gay and bisexual men. This trend continues today, although racial and ethnic minorities, women, and youth are becoming infected in increasing proportions. The south has the most people living with AIDS, followed by the north-east. The global situation is improving in some areas, but even if all HIV transmission could be completely stopped tomorrow, the long-term health, social and economic consequences will be devastating well into the 21st century. The magnitude of the epidemic and the continuing explosive risk of infection, coupled with the economic and infrastructural realities of the regions of the world, make prevention the only realistic approach.