About a quarter of deaths worldwide--many of them children--are caused by infectious organisms. The World Health Organization reports that new infectious diseases are continuing to emerge and familiar ones are appearing in new locations around the globe. What's behind this trend? How can invisible organisms cause such harm? And to what extent has human behavior amplified the problem? What You Need to Know About Infectious Disease provides an overview of infectious disease, drawing on reports of the Institute of Medicine. Written for a general audience, it describes the biology, history, and future trends of some of the world's most widespread and harmful infections and explains what we need to do--as individuals and as a society--to address this global challenge.