The Centers for Disease Control have defined AIDS as a syndrome characterized by unusual opportunistic infections and rare malignancies in otherwise healthy individuals with no other reason for immune system compromise. More than 35,000 AIDS cases and more than 20,000 AIDS deaths have been recorded in the United States. The AIDS virus is transmitted by blood and by direct contact of genital or rectal mucosa with infected semen or vaginal secretions. The majority of infected people will probably experience some degree of immune deficiency and perhaps overt AIDS. The time from infection to manifestation of symptoms varies from individual to individual. Opportunistic infections are the most common presenting signs that establish a diagnosis of AIDS. Several experimental therapies are being developed to correct the underlying immune dysfunction and to interrupt and neutralize the retroviral process. However, attempts to restore immune function through immune system modulation have been unsuccessful so far. Research on effective treatments must continue, but education remains the most effective way to stop the spread of AIDS. 68 references.