In less than 20 years, AIDS has become a pandemic requiring an unprecedented global response (see Figure 2-1) (UNAIDS and WHO, 2001). More than 60 million people have been infected with the human immunodeficiency virus (HIV) worldwide, and 20 million have died from AIDS, leaving an estimated 40 million adults and children living with HIV. Roughly 14 million children are living bereft of one or both parents who died from the disease. In 2001 alone, it is estimated that 5 million people became HIV-positive worldwide, 800,000 of them children (UNAIDS, 2002). Nearly one-third of those living with HIV/AIDS—11.8 million—are between 15 and 24 years of age (UNAIDS, 2002). Specific projections of the number of anticipated HIV/AIDS cases are difficult because the incidence of HIV infection is declining in some populations and increasing in others, HIV-testing continues to be voluntary, and reporting may be incomplete. Generally, the number of cases is expected to rise in areas where poverty, poor health systems, poor access to health care services, and gender inequality are prevalent; where resources for health care and prevention are limited; and where a high degree of stigma and denial is associated with HIV infection (Monitoring the AIDS Pandemic Network, 2000).

In 2001, the highest incidence of HIV/AIDS worldwide was in Africa, where an estimated 3.5 million adults and children were newly infected with HIV in that year alone (UNAIDS, 2002). Of the 40 million people living with HIV/AIDS worldwide at the end of 2001, 28.5 million were in sub-Saharan Africa (UNAIDS, 2002). The majority of adults living with HIV/AIDS in Africa are women under 25 years of age, whose infection rates are astonishingly high. At the end of 2001, mean HIV prevalence rates for