Overview
Cholera is an infection of the intestines caused by the bacterium Vibrio cholerae. It spreads through water or food contaminated with the stools of an infected person. Where people lack safe water, toilets and good hygiene, it can spread quickly and cause outbreaks.
Most infected people have mild symptoms or none. A smaller number develop severe watery diarrhoea that can cause dangerous dehydration within hours, and untreated severe cholera can be fatal. With quick fluid replacement, most people recover.
Symptoms
Symptoms start from 12 hours to 5 days after infection. They can include:
- Sudden watery diarrhoea, which in severe cases looks pale and thin, like water in which rice has been washed
- Nausea, vomiting and tummy pain
- Leg cramps
Signs that the body has lost too much fluid include:
- Intense thirst and a dry mouth
- Dark yellow, strong-smelling urine, or very little urine
- A fast heartbeat
- Low , which can cause dizziness or fainting
When to see a doctor
See a doctor soon for watery diarrhoea during an outbreak, after drinking unsafe water, or after travel to an area with cholera. In the meantime, keep drinking fluids, including .
Causes
Cholera is caused by swallowing Vibrio cholerae in water or food. This happens when sewage or the stools of an infected person reach drinking water or food, or when food is handled with unwashed hands. Raw or undercooked shellfish from contaminated water can also carry the bacteria.
Many infected people have no symptoms but can still pass the bacteria in their stools for a few days. Outbreaks follow floods, cyclones and other events that break down water and sanitation.
Risk factors
- Living without safe drinking water, toilets or places to wash hands
- Floods and other disasters that contaminate water, and displacement from home
- Eating raw or undercooked shellfish or seafood
- Travel to an area where cholera is spreading
- Low stomach acid, for example in people who take acid-reducing medicines
Complications
The main danger is dehydration. Severe fluid loss can lead to:
- Muscle cramps, from the loss of body salts
- Shock, a dangerous fall in
- Death, within hours if there is no treatment
Prevention
- Drink only safe water: boiled, bottled or properly treated. Avoid ice made from unsafe water
- Wash hands with soap and safe water after using the toilet, after cleaning a child, and before preparing or eating food
- Eat food that is freshly cooked and hot. Avoid raw or undercooked shellfish and seafood
- Wash raw fruit and vegetables with safe water, or peel them yourself
- Dispose of faeces safely and use clean toilets
- The oral cholera is used in outbreaks and for people at high risk, but does not replace safe water and hygiene
- should not be taken to prevent cholera
Diagnosis
Doctors suspect cholera from sudden severe watery diarrhoea, especially during an outbreak, and check how dehydrated the person is. Treatment for dehydration starts straight away.
A stool sample is tested in a laboratory to grow and identify the bacterium, ideally before are started. Quick test kits help to detect outbreaks, but treatment does not wait for them.
Treatment
The main treatment is to replace the water and salts the body has lost, quickly. Most people recover with (ORS), a powder mixed with clean water and drunk often.
People who are severely dehydrated need fluids through a vein in hospital, together with ORS and . Antibiotics shorten the illness and reduce the fluid needed, but do not replace fluids. Zinc is given to children to lessen the severity and length of the illness. Babies should keep being breastfed or given formula.
Myths and facts
Things people often say about this. Open each one to see what is true.
Myth“Cholera is always fatal.”What is true?
Fact
Many people with cholera have mild symptoms or none at all. It becomes dangerous when severe watery diarrhoea causes heavy loss of body fluid. Most people recover with prompt rehydration, which is why quick treatment matters so much.
Myth“Oral rehydration solution is only a home remedy. Cholera needs antibiotics to cure it.”What is true?
Fact
Replacing the lost fluid is the main treatment, using oral rehydration solution and, for severe dehydration, a drip. Antibiotics are added for severe cases and shorten the illness, but they do not replace the fluids.
Myth“Food and drink should be stopped to give the stomach a rest.”What is true?
Fact
The body is losing fluid all the time, so fluid has to be replaced all the time. Drinking plenty of rehydration solution is the main treatment, and a baby with watery diarrhoea should keep being breastfed or given formula.
Myth“You can catch cholera just by touching or sitting near someone who has it.”What is true?
Fact
Cholera spreads by swallowing food or water contaminated with infected stools. Casual contact is unlikely to spread it. Washing hands with soap after using the toilet and before handling food still matters a great deal.
Questions to ask your doctor
Tick the ones you want answered and take them with you.
Common questions
How quickly can cholera make someone seriously ill?
Symptoms start from 12 hours to 5 days after infection. In severe cases, heavy fluid loss can cause dangerous dehydration within hours, which is why severe watery diarrhoea needs emergency care.
Can cholera spread from person to person?
Casual contact is unlikely to spread it. It spreads through contaminated water and food, including food handled by an infected person who has not washed their hands. Washing hands with soap after the toilet and before food is the best protection.
Is there a vaccine for cholera?
Yes. Oral cholera vaccines, taken by mouth, are used to prevent and control outbreaks and for people at high risk. Most adults need two doses for full protection, and one dose gives shorter protection. The vaccine adds to safe water and hygiene and does not replace them.
