Infection is transmitted via the consumption of drinking water or food contaminated by the bacterium. Common sources of foodborne infection include raw or poorly cooked seafood, raw fruit and vegetables, and other foods contaminated during preparation or storage. Bacteria present in the faeces of an infected person are the main source of contamination. The bacterium can also live in the environment in brackish rivers and coastal waters. The disease can thus spread rapidly in areas where sewage and drinking water supplies are inadequately treated.
Cholera remains an ever-present risk in many countries.
New outbreaks can occur sporadically in any part of the world where water supplies, sanitation, food safety, and hygiene are inadequate. The greatest risk occurs in overpopulated communities and refugee settings characterized by poor sanitation and unsafe drinking water. People living in high-risk areas can protect themselves by following a few simple rules of good hygiene and safe food preparation. These include scrupulous washing of hands, especially before food preparation and eating, thorough cooking of food and consumption while hot, boiling or treatment of drinking water, and use of sanitary facilities. The most important treatment is rehydration, which consists of prompt replacement of the water and salts lost through severe diarrhoea and vomiting.