AIDS: A multicenter study, CPCRA 036, is recruiting more than one thousand HIV-infected people to help physicians decide when to change anti-HIV therapy. Although doctors currently change a patient's antiretroviral therapy when drug efficacy appears to wane, better tools are needed to decide when such changes would be most beneficial. A new technology that detects HIV RNA blood levels has been suggested as a way to gauge the effectiveness of therapy and predict when the disease may worsen. The Community Programs for Clinical Research on AIDS (CPCRA) team has chosen to use the branched DNA (bDNA) assay for HIV-1. Volunteers will be divided into two groups of 550 each, a current clinical practice (CCP) arm and an HIV RNA arm. Participants must meet eligibility requirements and receive their care at a participating CPCRA site. Call the AIDS Clinical Trials Information Service for further information.