A severe diarrheal disease caused by infection of the small bowel of humans with Vibrio cholerae. This facultatively anaerobic, curved, gram-negative, rod-shaped bacterium is rapidly motile by means of a single sheathed polar flagellum. Cholera is transmitted by the fecal-oral route. From its ancestral home in the Indo-Pakistani subcontinent, through movement of people by ships and other means of transportation, cholera has swept the world in seven pandemic waves. These involved the Western Hemisphere several times in the 1800s, and again in Peru in 1991. Whereas previous cholera outbreaks were associated with high mortality rates, through understanding of its pathophysiology it can now be said that no one should die of cholera who receives appropriate treatment soon enough.