The revision will allow more efficient tracking of human immunodeficiency virus (HIV), simplify reporting of AIDS cases, and increase the sensitivity and specificity of definition through greater diagnostic application of laboratory evidence of HIV infection. The major proposed changes apply to patients with laboratory evidence of HIV infection. These include HIV encephalopathy, HIV wasting syndrome, and a broader range of specific AIDS-indicative diseases. The revised definition also includes AIDS patients whose indicator diseases are diagnosed presumptively and the elimination of exclusions due to other causes of immunodeficiency. Some differences in the application of the definition to children and adults are noted. The new definition is effective immediately (August 1987). Appendixes provide additional information. 7 references.