The development of a cocktail of powerful antiretroviral drugs has transformed what was once an all-but-certain killer into a chronic illness that can be managed (at least for those who have access to treatment). In the United States, annual deaths have fallen from a peak of nearly 51,000 in 1995 to more than 14,100 in 2007, according to the Centers for Disease Control and Prevention. But there is still no cure or effective vaccine for Acquired Immune Deficiency Syndrome or the Human Immunodeficiency Virus that causes it.

In the United States, African Americans are the most severely affected racial or ethnic group, accounting for about 42.1 percent of all AIDS cases through 2007, compared with 40 percent for whites and 16.7 percent for Latinos, according to the CDC. Forty-eight percent of the cases were transmitted through male-to-male sexual contact, 25 percent through injection drug use, 17 percent through high-risk heterosexual contact and 7 percent through a combination of male-to-male sexual contact and injection drug use, according to the CDC. 

Worldwide, the disease killed an estimated 2 million people in 2008, including 280,000 children under 15 in age, according to the UNAIDS 2009 Epidemic Update.. About 71 percent of new infections in 2008 were in sub-Saharan Africa. All told, about 25 million people have died of the disease since it was first identified in 1981, according to the World Health Organization and UNAIDS. Meanwhile, an estimated 2.7 million people worldwide were newly infected in 2007, more than half of them under the age of 25, according to UNAIDS. Millions of victims in developing countries still lack access to treatment, despite major philanthropic campaigns. Updated March 2010