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 W,e modern history of the disease outside India begiħs; 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.” Later classical writers including Celsus, Aretaeus, and Caelius Aurelianus described a condition under the same name. By late 1669, Thomas Sydenham employed the term in describing an epidemic in London. The term was also widely used to describe endemic or sporadic diarrhea throughout the nineteenth century and earlier in western Europe and the Americas. This is sometimes specifically designated as cholera nostras.
The term cholera morbus has also been widely used in a manner that can cause confusion because it has been applied to indicate both epidemic and sporadic or endemic forms of illness marked by diarrhea. Today the term is applied as defined above and thus is limited to the disease caused by V. cholerae. Synonyms have included Asiatic cholera or cholera asiatica, epidemic cholera or cholera epidemica, malignant cholera, cholera asphyxia, and cholera spasmodica. It is now generally accepted that all cholera in the West prior to the nineteenth-century epidemics was endemic or sporadic - and not caused by V. cholerae. It is also generally accepted that the cholera of India prior to 1817 was an earlier expression of the epidemic cholera, with the first reference appearing in Western literature in the Lendas da India, published in 1543 by the Portuguese explorer Gaspar Correia. He describes an outbreak occurring in 1503 in the army of the Sovereign of Calicut. Cholera was also described in 1563 by Garcia da Orta in one of the earliest books printed in Goa. Its Portuguese name was mordexim, from which the French mort de chien is derived. Other Eastern terms were hyza (Arabic and Hindustani), tokhmu (Persian), bisoochtau (Sanskrit), and fural (Mah- ratta). That the differentiation is not universally accepted can be seen in the 1961 writings of the Indian bacteriologist S. N. De, who includes all types of conditions under one disease entry and therefore objects to the implications of the term “Asiatic” cholera. Nonetheless, this survey will be limited to the epidemic of Asiatic cholera, unless specifically indicated to the contrary.