Introduction

Human immunodeficiency virus (HIV) infection has expanded to become a global pandemic which threatens health in most areas of the world, and is now the leading cause of death among some segments of the population. For example, in 1995 in the USA, AIDS surpassed cancer as the predominant cause of death in young African–American women (25–44 years). From the beginning of the epidemic through to 31 December 1997, there have been 641,086 cases of AIDS and 390,692 AIDS deaths in the USA, according to the Centers for Disease Control (CDC). Rates in women, children, and injecting drug users (IDUs) and infection through heterosexual contact have been rising. In the USA in 1996, African–Americans represented 41% of adults/adolescents reported with AIDS, exceeding the proportion who are Caucasians for the first time. On a worldwide scale, the World Health Organization (WHO) has estimated that, as of the end of 1995, 6 million AIDS cases and approximately 20 million people were alive and infected with the HIV-1 virus. WHO estimates that nearly 10,000 new infections occur each day.

For the first time since the beginning of the epidemic, the number of AIDS deaths in the USA declined by 13% in the first half of 1996 compared to 1995. Most of the dramatic change, however, was seen among Caucasian homosexual males, and women and minorities continued to show increases in AIDS death rates. The factors explaining this discrepancy probably reflect restricted access for these groups to medical care, and particularly to the newer combination antiretroviral therapies.