Impact of the 1993 expanded AIDS surveillance case definition on reporting of persons without HIV risk information

To evaluate the impact of the 1993 expansion of the acquired immunodeficiency syndrome (AIDS) surveillance definition on reporting of persons with no HIV risk exposure information, we compared persons reported with and without risk in 1992 and 1993. The expanded case definition resulted in a large increase in both the number of persons reported with risk (121% increase) and without risk (167% increase). The changes in demographic characteristics for each group were similar from 1992 to 1993. Persons reported based on immunologic criteria were more likely and persons with pulmonary tuberculosis (PTB) less likely than those meeting the pre-1993 definition criteria to be reported with risk. Many persons with PTB were retrospectively identified from tuberculosis registries that do not systematically include HIV risk information. Ascertainment of risk information continues to be an essential part of AIDS surveillance with >90% of reports including risk exposure.