In parts of sub-Saharan Africa, 25 percent of the adult population is infected with the virus that causes acquired immune deficiency syndrome (AIDS), according to a report issued by the United Nations (UN) on June 23, 1998. In comparison, less than 1 percent of people between 15 and 49 years of age in the United States and Western Europe carry the AIDS virus.

The report, the UN's first country-by-country analysis of the AIDS pandemic, found that in 1997 about 21 million, or two-thirds, of the world's 30.6 million people infected with human immunodeficiency virus (HIV), the virus that causes AIDS, lived in the 21 countries of sub-Saharan Africa. Botswana and Zimbabwe had the highest rates of infection, with one in four adults carrying HIV.

In Asia about six million people were estimated to be carrying HIV in 1997. About 860,000 people in the United States and 480,000 in Western Europe were infected with HIV.

Authored by the World Health Organization (WHO) and the Joint United Nations Program on HIV/AIDS (UNAIDS), the report said AIDS was spreading virtually unchecked through much of the developing world. In developed countries expensive medical treatments have slowed AIDS mortality rates, but the majority of people infected with HIV in the developing world lack even basic health care and are likely to die from AIDS or AIDS-related infections, the report said.

However, the report noted that AIDS prevention programs, including public education campaigns, access to basic health care, and availability of condoms to prevent the spread of the sexually transmitted disease, were effective tools to slow the transmission of AIDS. The report cited Uganda and Thailand as examples of nations that effectively used prevention programs to reduce rates of HIV infection.