Infectious diseases. Old diseases return and new agents emerge.

Abstract

WESTERN MAN armed with therapies and public health strategies for preventing infections, has become complacent about the ready curability and control of infectious diseases. The general public is not aware of the complex and tenuous relationship that we have with the microbial world. Perturbations of this delicate symbiotic relationship contribute to the emergence of new diseases and the recrudescence of old diseases. In fact, often our therapeutic interventions themselves cause these perturbations.1-3 Historically, infectious diseases have played major roles in defining our empires, cultures, and daily lives.2As early as 430 BC, Thucydides4described, long before the concept of contagion, an epidemic that devastated Athens and, thereby, strongly influenced the outcome of the Peloponnesian war. The plague changed the face of Europe and then set the stage for the Renaissance. Currently, the acquired immunodeficiency syndrome pandemic is changing entire societies and, because it is contemporary, it touches