Non-vibrio cholera has been recognized as a clinical entity for as long as
cholera was known to be caused by Vibrio cholerae. Until 1968, the aetiologic agent of this syndrome was not known. Following a series of studies in patients with non-vibrio cholera it was found that these patients had large concentrations of Escherichia coli in the small bowel and stools which produced
cholera toxin-like
enterotoxins, and had fluid and
electrolyte transport abnormalities in the small bowel similar to patients with documented
cholera. Furthermore, these patients developed
antibodies to the
cholera-like
enterotoxin. Later studies showed that these strains, when fed to volunteers produced a
cholera-like disease and that two
enterotoxins were found to be produced by these organisms: a heat-labile
enterotoxin (LT) which is nearly identical to
cholera toxin, and a heat-stable
enterotoxin (ST), a small molecular weight
polypeptide. E. coli that produced one or both of these
enterotoxins were designated enterotoxigenic E. coli (ETEC). ETEC are now known not only to cause a severe
cholera-like illness, but to be the most common bacterial cause of acute diarrhoea in children in the developing world, and to be the most common cause of travellers' diarrhoea in persons who visit the developing world.