Cholera.

Few diseases invoke public fear as readily as cholera. In its most severe state, cholera can cause death from hypotensive shock within 12 h of the first symptom. Cholera typically occurs in epidemics, spreading rapidly within the community, especially if hygeinic conditions are poor. Fortunately, effective water treatment has limited the spread of cholera in most of the developed world, and the treatment of cholera by oral rehydration has dramatically reduced the mortality rate.