SURVEILLANCE OF AIDS-DEFINING CONDITIONS IN THE UNITED-STATES

Objective: To examine the reporting of AIDS-defining illnesses using two national surveillance systems. Methods: Comparison of AIDS indicator diseases reported to the national AIDS reporting system (ARS) for AIDS cases diagnosed from January 1990-December 1992 among individuals aged >13 years in 10 metropolitan areas, with that observed in the Adult/Adolescent Spectrum of HIV Disease (ASD) project, a surveillance project that monitors the clinical diagnoses of HIV-infected individuals receiving medical care. Results: In the 10 metropolitan areas, 39 265 individuals with AIDS were reported to ARS, and 5969 with AIDS had medical record reviews as part of ASD. At initial AIDS diagnosis, the number of indicator diseases reported to ARS was almost identical to the number observed in ASD (mean number of diagnoses, ARS 1.3; ASD 1.2). However, ASD recorded a greater number of diagnoses over time than ARS (mean number of indicator diagnoses >12 months after initial diagnosis, ASD 2.3; ARS 1.4). Conditions that typically occur late in the course of AIDS such as Mycobacterium avium infection and cytomegalovirus disease, were more frequently recorded by ASD than by ARS. Conclusion: ARS provides complete, population-based information on the frequency of AIDS-defining conditions at initial diagnosis. However, specialized surveillance projects such as ASD are needed to accurately describe subsequent AIDS-defining conditions.