Cholera, Geography of

Cholera is an acute diarrheal disease with a fecal-oral transmission route and is caused by ingestion of a dose of between 10,000 and 1 million Vibrio cholerae bacteria. The disease typically manifests in densely populated areas with high poverty, where water and sanitation remain unimproved. South Asia is the source region of cholera, as its tropical, estuarian environment creates a natural habitat for V. cholerae bacteria.

Cholera transmission can be divided into primary and secondary types. Primary cases result from infection by surface water sources where free-living bacteria are part of the natural ecosystem. Thus, primary transmission may infect someone who drinks untreated pond water or eats undercooked shellfish. Those infected by primary transmission may in turn infect others, considered a secondary pathway. Sources of secondary ...