SURVEILLANCE OF AIDS-DEFINING CONDITIONS IN THE UNITED-STATES

Objective: To examine the reporting of AIDS-defining illnesses using t wo national surveillance systems. Methods: Comparison of AIDS indicato r diseases reported to the national AIDS reporting system (ARS) for AI DS cases diagnosed from January 1990-December 1992 among individuals a ged >13 years in 10 metropolitan areas, with that observed in the Adul t/Adolescent Spectrum of HIV Disease (ASD) project, a surveillance pro ject 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 med ical record reviews as part of ASD. At initial AIDS diagnosis, the num ber 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). H owever, 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 cours e of AIDS such as Mycobacterium avium infection and cytomegalovirus di sease, were more frequently recorded by ASD than by ARS. Conclusion: A RS provides complete, population-based information on the frequency of AIDS-defining conditions at initial diagnosis. However, specialized s urveillance projects such as ASD are needed to accurately describe sub sequent AIDS-defining conditions.