Abstract
Between mid-century and 1992, there was a consensus that the battle against infectious diseases had been won, and the Surgeon General announced that it was time to close the book. Experience with human immunodeficiency virus/acquired immunodeficiency syndrome, the return of cholera to the Americas in 1991, the plague outbreak in India in 1994, and the emergence of Ebola in Zaire in 1995 created awareness of a new vulnerability to epidemics due to population growth, unplanned urbanization, antimicrobial resistance, poverty, societal change, and rapid mass movement of people. The increasing virulence of dengue fever with dengue hemorrhagic fever and dengue shock syndrome disproved the theory of the evolution toward commensalism, and the discovery of the microbial origins of peptic ulcer demonstrated the reach of infectious diseases. The Institute of Medicine coined the term 'emerging and reemerging diseases' to explain that the world had entered an era in which the vulnerability to epidemics in the United States and globally was greater than ever. The United States and the World Health Organization took devised rapid response systems to monitor and contain disease outbreaks and to develop new weapons against microbes. These mechanisms were tested by severe acute respiratory syndrome in 2003, and a series of practical and conceptual blind spots in preparedness were revealed.