Cholera

Published by Bupa's Health Information Team, July 2010.

This factsheet is for people who have cholera, or who are travelling to a country where there is a risk of cholera infection.

Cholera is an infection of the small bowel which can cause diarrhoea and vomiting. It's mostly found in areas that don't have safe drinking water, and where food hygiene and sewage disposal aren't very good. It can be life-threatening if the symptoms are severe.

About cholera

The main areas of the world in which cholera is found include Africa, Asia, the Middle East, Peru and some parts of Central America. Cholera doesn't occur in the UK, and it's rarely reported in people who travel to affected areas. Each year, between 12 and 25 people in England and Wales are diagnosed with cholera.

Cholera is also common in circumstances where people can't get access to clean water or sanitation is poor - for example, after a natural disaster or in a war zone.

Cholera is caused by infection with a bacterium called Vibrio cholerae. There are more than 100 forms (serotypes) of V. cholerae, but there are only two types that affect humans:

• V. cholerae O1, of which there are two subtypes (Classical and El Tor)
• V. cholerae O139

Symptoms of cholera

Cholera mainly affects your small bowel, causing watery diarrhoea and vomiting. If you have cholera, you may:

• have watery faeces with a mild, fishy smell and bits of mucus - this is sometimes called 'rice water' faeces because it looks like water in which rice has been washed
• feel sick and vomit
• have abdominal (tummy) cramps
• be dehydrated
• have a fever, but this is rare and usually only occurs in children

There is normally a delay of between a few hours and five days from when you become infected with cholera and when you start to get symptoms. This is known as the incubation period. Most people get symptoms after two to five days.

The symptoms of cholera can vary from mild to severe. About three-quarters of people who are infected don't realise they have it, as they don't become ill. Less commonly, cholera can cause severe diarrhoea. This can lead to extreme dehydration and can potentially be life-threatening.

Although not necessarily a result of cholera, if you have these symptoms and they are severe, you should seek urgent medical advice.

Causes of cholera

The symptoms of cholera are caused by the V. cholerae bacteria producing a poison (toxin) in your small bowel. A large number of the V. cholerae bacteria are required to produce enough toxin to cause the symptoms.

Cholera is usually spread through water contaminated with infected faeces. If you drink contaminated water you may develop symptoms. You can also get cholera from contaminated food, particularly poorly cooked seafood. It's rare to catch cholera directly from another person.

Diagnosis of cholera

Your GP will ask about your symptoms and examine you. If you have recently travelled abroad, you should let your GP know which countries or regions you have recently visited (including any stopovers). He or she may ask you for a sample of your faeces (also known as a stool sample), which will be sent to a laboratory and tested to see if you are infected with the cholera bacteria.

Treatment of cholera

Self-help

The main treatment for cholera is to replace the fluids that you have lost through diarrhoea. Your body will then usually fight off the infection by itself. You should drink enough fluids to replace those you have lost. It's also advisable that you take an oral rehydration therapy to replace lost salt and minerals. You can buy these from your pharmacist. Always read the patient information that comes with your medicine and if you have any questions, ask your pharmacist for advice.

You can also make homemade solutions using sugar and salt, but you should contact your GP or pharmacist for advice first.

Medicines

If your symptoms are severe, your GP may prescribe you antibiotics to take, such as doxycycline and tetracycline. These antibiotics can help control your diarrhoea and stop you losing any more fluids.

Hospital treatment

If you are very dehydrated you may need hospital treatment. You will have a drip inserted into a vein in your hand or arm to give you fluids.

Prevention of cholera

There are a number of precautions you can take to help reduce your risk of getting cholera if you are travelling to an affected area.

• Only drink bottled water (make sure the seal is intact) or tap water that has been boiled. You can drink water that has been treated with chlorine or iodine, but don't have ice as the V. cholerae bacteria can survive the freezing process.
• Eat freshly prepared foods that have been cooked thoroughly and are still hot. Don't eat raw vegetables such as green salads as they may have been washed in contaminated water. As a general rule, only eat raw vegetables and fruit that you can peel.
• Wash your hands after going to the toilet and always before preparing and eating food, or drinking water.

Vaccine

A cholera vaccine (Dukoral) is currently available in the UK. Most people who travel abroad don't need to have the vaccine as taking preventive measures will usually provide enough protection against cholera. However, you may be offered the vaccine if you plan to stay in an area of known cholera outbreaks long-term - especially if there is limited access to good medical care.

The vaccine is given orally (you take it by mouth), and it comes in sachets that you dissolve in water. It can be given to adults and children over two. The vaccine course is:

• two doses for adults and children aged over six years
• three doses for children aged two to six years

You shouldn't eat or drink anything for one hour before or after taking the vaccine. The doses must be separated by a period of between one and six weeks. You must have completed the course at least a week before you plan to travel to an area with cholera.

The cholera vaccine doesn't give you life-long immunity and you will need to have a booster to keep you protected. Adults and children over six need the booster two years after the initial dose and children aged two to six need it six months after.

The vaccine only provides protection against infection caused by one type of the V. cholerae bacteria, so it's very important to continue to take other preventive measures.

For answers to frequently asked questions on this topic, see Common questions.

For sources and links to further information, see Resources.