Although cholera infections are rare in the U.S. and other developed countries, developing nations have between 3 million and 5 million cases of cholera reported and between 100,000 and 120,000 deaths annually. Most of those cases are clustered in Africa, Haiti and Southeast Asia [source: WHO]. Severe cases, estimated to be 5 to 10 percent of those affected, can be fatal if treatment isn't received promptly [source: CDC].
Cholera is a foodborne illness caused by the bacterium Vibrio cholerae, and it occurs after consuming food or water that's been contaminated with feces from a person infected with the bacterium. Contamination may happen through inadequate handwashing and hygiene or in areas with inadequate sanitation and water treatment. Cases of cholera in developed nations are rare, and they're most often associated with eating contaminated raw oysters.
Cholera's hallmark, profuse diarrhea, won't appear until two to three days after exposure to the bacterium.
Vibrio cholerae is an enterotoxin, which means it's a bacterium that infects the intestines. The toxins produced by this bacterium attack the cells in the lining of the intestine, causing those cells to release large amounts of water. With nowhere to go but out, the infection progresses to generous amounts of foul-smelling watery diarrhea "that resembles rice water" [source: Davis]. The accompanying fast and significant fluid loss causes severe dehydration, and treatment primarily involves rehydration.