The Cholera reference article from the English Wikipedia on 24-Jul-2004
(provided by Fixed Reference: snapshots of Wikipedia from wikipedia.org)

Cholera

Support a children's charity online
Cholera (also called Asiatic cholera) is a disease of the intestinal tract caused by the Vibrio cholerae bacterium. These bacteria are typically ingested by drinking water contaminated by improper sanitation or by eating improperly cooked fish, especially shell fish. Symptoms include diarrhea, abdominal cramps, nausea, vomiting, and dehydration. It is treated with rehydration and antibiotics, but in severe cases, cholera can lead to death.

Vibrio cholerae causes disease by producing a toxin that disables the GTPase function of G proteins which are part of G protein-coupled receptors in intestinal cells. This has the effect that the G proteins are locked in the "on position" binding GTP (normally, the G proteins quickly return to "off" by hydrolizing GTP to GDP). The G proteins then cause adenylate cyclases to produce large amounts of cyclic AMP (cAMP) which results in the loss of fluid and salts across the lining of the gut.

The point of this is that the resulting diarrhea allows the bacterium to spread to other people under unsanitary conditions.

Carriers of the cystic fibrosis gene are protected from the severe effects of cholera because they don't lose water as fast. This explains the high incidence of cystic fibrosis among populations which were formerly exposed to cholera.

Recent genetic research has determined that a person's susceptibility to cholera (and other diarrheas) is affected by their blood type. Those with type O blood are the most susceptible. Those with type AB are the most resistant, virtually immune. Between these two extremes are the A and B blood types, with type A being more resistant than type B.

see also John Snow and Robert Koch

References:

External links: