The New AIDS Case Definition

THE CENTERS for Disease Control (CDC) has proposed a new AIDS case definition to be effective April 1, 1992. This new definition will include those persons already meeting the 1987 AIDS definition1and will add all adults and adolescents infected with the human immunodeficiency virus and with CD4 lymphocyte counts less than 200/μL (200×106/L).2 We review herein the importance of the CDC definition and the implications of the new definition, both for individuals and for the system of AIDS care. Our discussion will primarily focus on the effects of the 1992 definition on San Francisco, Calif. Although San Francisco has a distinctive case mix and system of AIDS care, we believe that these local effects portend changes that will be felt across the country. Historical Perspective The new definition represents the third revision of the CDC AIDS case definition. The list of indicator AIDS diagnoses in the original