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• About one million Vibrio cholerae bacteria must be ingested to cause cholera in normally healthy adults, although increased susceptibility may be observed in those with weakened immune systems, individuals with decreased gastric acidity (as from the use of antacids), or those who are malnourished.
• The last major outbreak of cholera in the United States was in 1911.
• 1,099,882 cases and 10,453 deaths were reported in the Western Hemisphere between January 1991 and July 1995.
• On average, one case of cholera is reported in the United States every week.

Vibrio cholerae causes disease by producing a toxinA toxin is a substance that causes either permanent or reversible injury to the health of a living thing on contact or absorption, typically by interacting with biological macromolecules such as enzymes and receptors. The term is usually reserved for natu that disables the GTPaseGTPases are a large family of enzymes that can bind and hydrolyze GTP. The GTP binding and hydrolysis takes place in the highly conserved G domain common to all GTPases. GTPases play an important role in: Signal transduction at the intracellular domain of function of G proteinG-Proteins short for Guanine Nucleotide Binding Proteins are a family of proteins involved in second messenger cascades. They are so-called because of their signaling mechanism, which uses the exchange of guanine di phosphate ( GDP) for guanine triphosphas which are part of G protein-coupled receptorIn cell biology, a G-protein-coupled receptor is one of a class of integral membrane proteins belonging to the 7TM superfamily of transmembrane receptors, examples being receptors of the olfactory epithelium that bind odorants and receptors of the neurotrs in intestinalTh intestine is the portion of the alimentary canal extending from the stomach to the anus and, in humans and other mammals, consists of two segments, the small intestine and the large intestine. In humans, the small intestine is further subivided into th cells. This has the effect that the G proteins are locked in the "on position" binding GTPGTP (also known as guanylyl imidodiphosphate guanosine-5'-triphosphate or guanosine triphosphate is a chemical compound ( nucleotide) that is incorporated into the growing RNA chain during synthesis of RNA and used as a source of energy during synthesis o (normally, the G proteins quickly return to "off" by hydrolizing GTP to GDPGDP ( guanosine di phosphate) is a chemical compound essential to signal transduction in living cells. It is created by the actions of GTPases on GTP. Nucleotides.). The G proteins then cause adenylate cyclaseAdenylate cyclase (EC 4. 1, also known as adenylyl cyclase or AC is a lyase, an enzyme that catalyzes the conversion of ATP to 3',5'-cyclic AMP (cAMP) and pyrophosphate. cAMP is an important molecule in eukaryotic signal transduction, a so-called second ms to produce large amounts of cyclic AMP (cAMP) which results in the loss of fluid and salts across the lining of the gut.

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.

The scientists with major contributions to fighting cholera are: John Snow (who found the link between cholera and drinking water in 1854), and Robert Koch who identify the bacillus causing the disease.