It has a short incubation period, from less than one day to five days, and produces a toxin which causes 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. Vibrio cholerae is often found in the aquatic environment and is part of the normal flora of brackish water and estuaries. Human beings are also one of the reservoirs of the pathogenic form of Vibrio cholerae .
Cholera is spread by contaminated water and food.
Sudden large outbreaks are usually caused by a contaminated water supply. In highly endemic areas, it is mainly a disease of young children, although breastfeeding infants are rarely affected. Washing hands after defecation, and particularly before contact with food or drinking water, is equally important.