Robert S. Lawrence, M.D. and Director of Center for a Livable Future at Johns Hopkins Bloomberg School of Public Health discusses the evidence linking the inappropriate use of antibiotics in sub-therapeutic doses as growth promoters in the industrial production of food animals in the United States to the emergence of bacteria resistant to these antibiotics and the subsequent threat to the health of the public. Confined animal feeding operations or CAFOs where thousands of animals are crowded together and exposed to antibiotics used for growth promotion create the perfect environment for eliminating bacteria susceptible to antibiotics and selecting out the bacteria with genetic mutations allowing them to survive in the presence of the antibiotic. Inadequate attention has been given to the use of antibiotics as growth promoters that are important in the treatment of infections in humans, especially the very young, the very old, and those whose immune systems are weakened by chemotherapy for cancer or by infection with HIV. Less