Introduction
From birth until death, the human body is under relentless attack by hordes of living organisms that compete for survival in our environment. The air we breathe, the food we eat, the ground we walk on, the water we drink, the buildings we live in, the vegetation that surrounds us-all harbor infectious organisms.
These agents of infectious disease come in all shapes and sizes, from microscopic viruses, bacteria, and protozoans to foot-long parasitic worms. While these germs may vary wildly in appearance, they all share a dependence on human beings for at least part of their life cycle. They enter the body by hitching a ride in contaminated food or beverages, or by invading the genital tract or the eyes. They may attack even before birth, passing through the mother's placenta where they attack the developing cells of the fetus so that the baby may be diseased or deformed at birth.
Information in this site comes from the most up-to-date sources available and includes some of the most recent research in the field of infectious disease. Readers should keep in mind, however, that changes occur very rapidly in this field. Because space limitations made it impossible to include all of the information in this very large specialty, a detailed bibliography has been provided for readers who seek additional sources of information.
