Arachu Castro, Ph.D., M.P.H., is Professor and Samuel Z. Stone Endowed Chair of Public Health in Latin America and Director of the Center for Health Equity in Latin America at the Celia Scott Weatherhead School of Public Health and Tropical Medicine at Tulane University. Her major interests are how social inequalities are embodied as differential risk for pathologies common among the poor and how health policies may alter the course of epidemic disease and other pathologies afflicting populations living in poverty. Dr.