An estimated forty million people carry the human immunodeficiency virus (HIV), and five million more become newly infected annually. In recent years, many HIV-infected patients in wealthy nations have enjoyed significantly longer, good-quality lives as a result of antiretroviral therapy (ART). However, most infected individuals live in the poorest regions of the world, where ART is virtually nonexistent. The consequent death toll in these regions?especially sub-Saharan Africa?is begetting economic and social collapse. To inform the multiple efforts underway to deploy antiretroviral drugs in resource-poor settings, the Institute of Medicine committee was asked to conduct an independent review and assessment of rapid scale-up ART programs. It was also asked to identify the components of effective implementation programs. At the heart of the committee's report lie five imperatives: * Immediately introduce and scale up ART programs in resource-poor settings. * Devise strategies to ensure high levels of patient adherence to complicated treatment regimens. * Rapidly address human-resource shortages to avoid the failure of program implementation. * Continuously monitor and evaluate the programs to form the most effective guidelines and treatment regimens for each population. * Prepare to sustain ART for decades.