Having reviewed the ways in which poverty, structural violence, and infectious disease confine poor populations to vicious cycles of suffering and despair, we now examine the implications of these understandings on the design of health interventions. As shown by disease patterns in Haiti and Rwanda, social forces interact with human biology and affect who falls ill and who has access to care. Thus, use of a biosocial analytical framework provides a useful and effective tool for designing and implementing health interventions to address these inequalities. Failure to use a biosocial lens often gives rise to charity and development models of health intervention that replicate preexisting unequal structures. Such models localize blame for disease with the poor themselves. In contrast, a biosocial lens makes clear that disease among the poor results from the embodiment of structural violence and requires that any serious attempt to address disease in resource-poor settings incorporates efforts for social change. Through commitment to models built on the principles of social justice, we have found that advocacy and long-term partnerships with the public sector and the communities in which we work are indispensable to sustainable transformations in health that reduce suffering caused by infectious and chronic disease. Biosocial understandings of disease in Haiti and Rwanda reveal that a sustainable response must not only make available the fruits of modern medicine (ie, diagnostic tools, pharmaceuticals, and trained clinicians) but must also address the consequences Poverty, Global Health, and Infectious Disease of deep poverty: limited transportation, poor housing, and food scarcity, among others. In Haiti, Rwanda, and numerous other settings, Partners In Health and local partners provide care that integrates social and economic programs. These programs include constructing homes and schools, establishing potable water systems, and providing food and transportation stipends. In addition, paid community health workers are used to deliver top-quality health care to patients in their homes, rather than requiring sick, impoverished individuals to confront innumerable barriers to reaching clinics and hospitals. Such solutions, which privilege a biosocial approach to identifying and breaking down barriers to care, have resulted in remarkable successes in addressing epidemics of HIV/AIDS, TB, malaria, and other communicable and chronic diseases in some of the most challenging domestic and global settings. 33 