Luncheon Presentation by Dr. Margaret Chan, Director-General, World Health Organization Constant mutation and adaptation are the survival mechanisms of the microbial world. Changes in the way people inhabit the planet have placed unprecedented pressure on this volatile microbial world. As a result, new diseases are emerging at an alarming pace, old diseases are becoming permanently established in new places, and resistance to antibiotics is rendering many mainstay drugs useless, raising the specter of a post-antibiotic era. Why has human activity in a world of radically increased interdependence made infectious diseases a much larger menace? Which new diseases are likely to be socially and economically destructive, and which are likely to remain highly localized? What are some of the many mechanisms, operated by the World Health Organization and its partners that keep the world alert to infectious disease threats and ready to respond?