According to the United Nations organization UNAIDS, as of 2003 there were an estimated 40 million persons living with HIV and AIDS worldwide. Of these, 37 million were adults, and 2.5 million were under age 15. The overwhelming majority of persons with HIV live in resource-poor countries.

As of December 2002, 517,000 persons were known to be living with HIV and AIDS in the United States. The U.S. Centers for Disease Control and Prevention (CDC) estimates that 170,000 more Americans are infected with HIV but do not know it.

Additionally, CDC estimates that 501,669 persons had died from AIDS in the U.S. as of December 2002.