The acquired immunodeficiency syndrome (AIDS) continues to pose a significant threat to humanity. The World Health Organization (WHO) estimates that 11.7 million people have already died from AIDS since the beginning of the epidemic, and 30.6 million more are infected with the human immunodeficiency virus (HIV), the agent known to cause AIDS. In the United States as of June 1997, a total of 612,078 cases of AIDS had been reported to the Centers for Disease Control and Prevention (CDC).
