Cholera is an acute intestinal infection caused by the bacterium Vibrio cholerae. It has a short incubation period, from less than one day to five days, and produces an enterotoxin that causes a copious, painless, watery diarrhoea that can quickly lead to severe dehydration and death if treatment is not promptly given.
Vomiting also occurs in most patients.
Most persons infected with V. cholerae do not become ill, although the bacterium is present in their faeces for 7-14 days. The vibrio responsible for the seventh pandemic, now in progress, is known as V. cholerae O1, biotype El Tor. The disease then spread rapidly to other countries of eastern Asia and reached Bangladesh in 1963, India in 1964, and the USSR, Iran and Iraq in 1965-1966. In 1970 cholera invaded West Africa, which had not experienced the disease for more than 100 years. The disease quickly spread to a number of countries and eventually became endemic in most of the continent.