The goal of antiretroviral therapy is maximal suppression of HIV-1 replication. Yet studies show that there is ongoing replication of latent virus in the blood and lymphoid tissues of some patients receiving potent antiretroviral therapy who have had suppressed plasma HIV-1 RNA levels for prolonged periods of time. This continued viral persistence and replication could eventually result in virologic failure and clinical progression as well as selection and transmission of resistant HIV-1. There is a need to identify, quantify, and determine significance of viral reservoirs in compartments other than blood. A5077 is designed to evaluate the relationship between viral load in blood and nonblood compartments and time to virologic failure in patients initiating or changing potent antiretroviral therapy.