Cholera is a potentially fatal bacterial infection caused by consuming contaminated food or water.
Not everyone who becomes infected will develop symptoms, but those who do will usually experience:
These symptoms generally develop within a few days of infection, although they can sometimes occur after just a few hours.
Without treatment, the combination of diarrhoea and vomiting can cause a person to quickly become dehydrated and go into shock (where there's a sudden massive drop in blood pressure). In the most severe cases, cholera can be fatal.
Cholera can spread if food and, in particular, water become contaminated with the stools of an infected person. This is why cholera is most widespread in regions of the world with poor sanitation, such as parts of:
- sub-Saharan Africa
- south and south-east Asia
- the Middle East
- central America and the Caribbean
Mass outbreaks of cholera often occur after natural disasters or during war, as a result of overcrowding in poor living conditions and a lack of access to clean water.
The World Health Organization estimates that there are 1.4 to 4.3 million cases of cholera worldwide every year. The condition is also responsible for many thousands of deaths.
There haven't been any cases of cholera originating in England and Wales for over 100 years, although travellers do occasionally bring the infection back with them. However, this is rare, with only six cases of cholera reported in England and Wales during 2013/14.
Advice for travellers
If you're travelling to parts of the world known to be affected by cholera, you should take some basic precautions to prevent a cholera infection and other causes of travellers' diarrhoea.
For example, you should:
- only drink water that's been recently boiled, or drink from a bottle that's been properly sealed
- avoid eating ice cream and don't have ice in your drinks
- avoid uncooked fruit and vegetables, unless you've washed them in safe water or peeled them yourself
- avoid shellfish, seafood and salads
Read more about food and water safety abroad.
Vaccination against cholera may sometimes be recommended if you're travelling to areas where the infection is widespread, particularly if you're an aid worker and likely to have limited access to medical services.
You should speak to a nurse or doctor about whether you need a cholera vaccination well in advance of travelling, if you're considering visiting an area affected by cholera.
The cholera vaccine is available as a drink, which is given in two or three separate doses that are taken one to six weeks apart.
The vaccine is estimated to be about 85% effective in the months after vaccination, although the level of protection gradually reduces over time and booster doses will eventually be needed if you continue to be at risk.
Read more about cholera vaccination.
Cholera can be easily treated using oral rehydration solution (ORS) to prevent dehydration and shock. ORS comes as a sachet containing a mixture of salts and glucose, which is dissolved in water. It's ideal for replacing the fluids and minerals that are lost when a person becomes dehydrated.
ORS sachets are available from pharmacists, camping shops and travel clinics. If you're travelling to regions of the world affected by cholera, you should take ORS sachets with you as a precaution.
When a person with cholera is very severely dehydrated, intravenous antibiotics may be recommended to shorten the duration of diarrhoea and speed up rehydration.
Read more about accessing healthcare abroad.