Where did our infectious diseases come from? The evolution of infectious disease.

Infectious diseases have been evolving from the earliest days of life on earth. Major factors influencing their developments include the splitting of continents (continental drift), the radiation of early primates into present-day forms, migrations of man around the world, the ending of the Ice Age, the invention of agriculture, the domestication of animals, the increase in populations, and the urbanization of societies. The impact of such basic changes on infectious diseases is reviewed.