Abstract

Parasites are the major cause of ill health and early death in the world today. Malaria, sleeping sickness, amoebic dysentery, and hookworm infection are examples of commonplace parasitic diseases that are endemic in most parts of the world (see Health, Healing, and Disease). They were significant threats in prehistory, especially in cultures whose social complexity outstripped the development of effective sanitation, hygiene, and germ theory awareness.