Cholera is an acute, diarrheal illness caused by infection of the intestine with the bacterium Vibrio cholerae. The infection is often mild or without symptoms, but sometimes it can be severe. Approximately one in 20 infected persons has severe disease characterized by profuse watery diarrhea, vomiting, and leg cramps. In these persons, rapid loss of body fluids leads to dehydration and shock. Without treatment, death can occur within hours.

A person may get cholera by drinking water or eating food contaminated with the cholera bacterium. In an epidemic, the source of the contamination is usually the feces of an infected person. The disease can spread rapidly in areas with inadequate treatment of sewage and drinking water.

The cholera bacterium may also live in the environment in brackish rivers and coastal waters. Shellfish eaten raw have been a source of cholera.  The disease is not likely to spread directly from one person to another; therefore, casual contact with an infected person is not a risk for becoming ill.

The main areas of the world in which cholera is present are Africa, Asia and parts of the Middle East.

A cholera vaccine (Dukoral) has been available in the UK since 2004.

Dukoral is an oral vaccine (you take it by mouth) that comes in sachets that you dissolve in a drink. It can be used by 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 one hour before or after taking the vaccine. The doses must be separated by a period of one week. You must have completed the course at least a week before you plan to travel to an area with cholera.

You will need to have a booster vaccine to keep you protected against cholera. This is needed after:

• two years for adults and children over six
• six months for children aged two to six

A few people will have side-effects after having the cholera vaccine, but usually these are very mild. You may have mild symptoms such as tummy pain or cramps, diarrhoea and feeling sick.