Cholera is an acute, diarrheal illness caused by a bacterial infection. In severe cases, rapid loss of body fluids leads to dehydration and shock. Without treatment, death can occur within hours.
Cholera spreads via infected drinking water or food. In an epidemic, the source of the contamination is usually the feces of an infected person. The disease can spread rapidly in areas with inadequate treatment of sewage and drinking water.
Source: US Center for Disease Control