On Jun. 30, 1982, persuasive evidence that the HIV disease was caused by an infectious agent was presented at a meeting held at the New York Department of Health: cases had been reported in intravenous drug users, homosexuals, hemophiliacs, and Haitians.

One month later, the CDC reported 34 cases of opportunistic infections in Haitian patients. The pattern of infections was “similar to the pattern recently described among homosexual males and IV drug users.

“By January 1983, epidemiological evidence from CDC’s investigations strongly suggested that blood and blood products transmitted AIDS and that the disease could be transmitted through intimate sexual
contact. The evidence that the AIDS agent was blood-borne was the result of two findings. First, AIDS was occurring in transfusion recipients who did not belong to any known high-risk group and in individuals with hemophilia who had received AHF concentrate. Second, the epidemiological patterns of AIDS was similar to that of hepatitis B, another blood-borne disease.