Figure 1

a – AIDS cases by date of report, United States, 1984–1993 Legend: Number of AIDS cases by quarter year of report, United States, 1984–1993. AIDS surveillance criteria were modified in 1987[*] and 1993[†]). Source: Centers for Disease Control and Prevention.[15] b – AIDS cases by date of diagnosis, United States, 1986-1993 Estimated AIDS-opportunistic illness incidence (represents an estimate of AIDS trends if the surveillance definition had not been revised in 1993), adjusted for delays in reporting, by quarter year of diagnosis, United States, 1986-1993. Source: Centers for Disease Control and Prevention.[17]