Cholera is a bacterial infection. It is caused by drinking water contaminated with vibrio cholerae bacteria, or by eating food that has been in contact with contaminated water.
The most common symptoms of cholera are:
Left untreated the combination of diarrhoea and vomiting can cause a person to quickly become dehydrated (lack of fluids inside their body) and go into shock (experience a sudden massive drop in blood pressure). In the most severe cases these conditions can be fatal.
How cholera is spread
Around three-quarters of people who are exposed to cholera bacteria do not develop any symptoms. However, these people can contaminate water by passing stools (faeces) that contain bacteria into water, or pass on the disease through poor food hygiene.
How common is it?
Because of the improvements in sanitation and water hygiene over the last 100 years or so, cholera has been wiped out in much of the world.
Cases of cholera are now largely confined to regions of the world with poor sanitation and water hygiene, such as:
- sub-Saharan Africa (all the countries south of the Sahara desert)
- south and south-east Asia, particularly India and Bangladesh
- some parts of the Middle East
- some parts of South America
Even in these parts of the world, cholera remains relatively uncommon. However, mass outbreaks can occur in times of natural disaster, war, or civil unrest due to overcrowding of people in poor living conditions and a lack of access to clean water.
For example there was a large outbreak of cholera in Haiti in 2010 after an earthquake.
Advice for travellers
If you are travelling to parts of the world known to be affected by cholera, following some basic precautions should prevent you from contracting a cholera infection:
- maintain good personal hygiene
- only drink water from a bottle that has been properly sealed or carbonated
- do not buy ice cream, ice cubes or fruit juices from street vendors
- do not eat raw vegetables, peeled fruit, shellfish or salads
Travellers who do contract cholera tend to have a much better outlook as they are generally healthy and well fed.
Unfortunately many people in the developing world who catch cholera are often malnourished and in a poor state of health so they are much more vulnerable to the effects of the infection.
There is a vaccine (given as a drink) that protects against cholera. It is estimated to be 85% effective.
Vaccination is usually only required for:
- people travelling in remote areas where cholera epidemics are occurring and there is limited access to medical care
- those intending to visit high-risk areas such as refugee camps or war zones
- those taking part in disaster relief operations
These people include emergency relief workers, members of the armed forces and healthcare workers.
It is important to get advice from your nurse or doctor about whether you need a cholera vaccination well in advance of travelling.
Read more about travel vaccinations.
Cholera needs prompt treatment with oral rehydration solution (ORS) to prevent dehydration and shock. ORS comes in a sachet. It is made up of a mixture of salts and glucose, which are dissolved in water. ORS is ideal for replacing the fluids and minerals that are lost when a person becomes dehydrated.
As well as treating dehydration and shock with ORS, antibiotics can be used to treat the underlying infection.
ORS sachets are available from many pharmacists, camping shops and travel clinics. If you are travelling to regions of the world affected by cholera, take ORS sachets as a precaution.