Cholera is an acute diarrheal disease usually accompanied by vomiting and resulting in severe dehydration or water loss and its consequences. The disease, in the strict sense of the term cholera, is caused by a specific, comma-shaped bacterium, Vibrio cholerae, first isolated in Egypt and Calcutta by Robert Koch and colleagues in 1883. Mortality rates have reached up to 50 percent and even 70 percent of those with the disease during epidemics. It has apparently been long endemic in the Ganges Delta of India and Bangladesh from which it has spread in periodic epidemics to other parts of India, the East, and eventually to much of the rest of the world. Most of this spread has occurred since 1817, when trie modern history of the disease outside India begins; it is now generally agreed that some seven pandemics have occurred since its initial spread. The most recent began in 1961 and is only now receding. The bacterium is disseminated by the so-called fecal-oral route as a consequence of sewage and fecal contamination of water supplies and foodstuffs. This indirect transmission long made its spread difficult to understand.

In the course of history, the term “cholera” has been variously applied. In order to understand the literature of cholera in the past, the reader must also understand these varying usages. The word “cholera” appears first in the Hippocratic corpus and there refers to sporadic diarrheal disease. It has been suggested that it derives from the Greek word for “bile” and for “flow” (difficult to accept since cholera excreta are singularly free of bile), or from a Greek work for “spout” or “gutter.”