"Cholera is an acute illness that results in profuse watery diarrhoea," explains Professor Willem Sturm, Head of the Medical Microbiology and Infectious Diseases department at the Nelson Mandela School of Medicine in Durban.
"It's caused by the Vibrio cholerae bacterium, a relatively simple organism that lives in fresh water. Cholera is a bacterial infection.
Over the years160 strains of cholera have been identified. Of these strains, only two produce a toxin that causes diarrhoea. These are serogroups 01 and 0139. Simply put, the numbers help distinguish when the strains were identified. Vibrio cholerae 0139, for example, was only discovered about six years ago, while Vibrio cholerae 01 was the first strain to be identified many years ago.
"Under normal circumstances, your gut absorbs water and nutrients from the food you eat and drink, but when you are infected with cholera, the opposite occurs. The toxin released by the bacteria causes increased secretion of water and chloride ions from the intestine, which results in watery diarrhoea. If the diarrhoea goes untreated, death can result from severe dehydration and shock."