Cholera

Introduction

Cholera is an acute diarrhoeal disease caused by the bacterium Vibrio cholera. Toxigenic V. cholerae found in fresh and slightly salty water, often associated with shellfish and aquatic plants.

It is usually associated with poverty, poor sanitation and poor access to clean drinking water. It can also be a major problem affecting those in refugee camps and as a result of natural disasters which disrupt water and sanitation systems.

Globally there are an estimated 1.3 – 4 million cases and an average of 95,000 deaths per year caused by cholera. Rehydration is the main management for treatment.

An effective vaccine is available for travellers whose activities or medical history puts them at increased risk of disease.1

The following is a summary about the disease. For further details speak to your local pharmacist or GP.

How is cholera spread?

Cholera is mainly transmitted through faecal contamination of food or water. Infection mostly occurs from:

  • Drinking water in which cholerae is found naturally or which has become contaminated through infected faeces
  • Consuming contaminated fish and shellfish
  • Consuming food which has been handled by an infected person or cleaned in contaminated water

Humans are the only known natural host and direct transmission from person to person is uncommon. Large numbers of bacteria are needed to establish infection in those with normal gastric acidity.1

In which countries is cholera found?

Cholera most commonly occurs in areas without clean water supply or modern sewage system such as parts of Africa and Asia. Countries which account for 80% of all cases reported include:

  • Afghanistan
  • Democratic Republic of the Congo (DRC)
  • Haiti
  • Kenya
  • Tanzania

Countries or areas which have reported outbreaks of cholera between 2010 and 2014 can be found here.2

Risk areas can change  therefore it is important to refer to country specific information found here.3

What are the signs and symptoms of cholera?

For asymptomatic people (those without symptoms) the infection is mild. They shed the bacteria from between 2 days and 2 weeks.

In other cases, symptoms occur between 2-5 days and include:

  • Diarrhoea
  • Nausea and vomiting1

However, in many cases it causes severe diarrhoea, sometimes with being sick (vomiting).4

What are the complications of cholera?

In some cases severe diarrhoea can occur. The volume of fluid lost can be up to 20 litres a day. If not replaced this can quickly lead to serious dehydration and can even be fatal.4

How is cholera treated?

Treatment for cholera include:

  • Rehydration therapy – prompt restoration of lost fluids and salts to prevent dehydration
  • Antibiotic treatment – for severe diarrhoea

Antidiarrhoeal drugs are not recommended.1

What advice is there for those travelling to high risk countries?

For the majority of travellers, the risk of acquiring cholera can be reduced by following advice on food and water hygiene and by ensuring good personal hygiene.1

Do:

  • Wash your hands with soap and water regularly, especially after using the toilet and before preparing food or eating
  • Only drink tap water that’s been boiled or bottled water
  • Brush your teeth using bottled or boiled water

For the majority of travellers, the risk of acquiring cholera can be reduced by following advice on food and water hygiene and by ensuring good personal hygiene.1

DO:

  • Wash your hands with soap and water regularly, especially after using the toilet and before preparing food or eating
  • Only drink tap water that’s been boiled or bottled water
  • Brush your teeth using bottled or boiled water

DO NOT:

  • Do not eat uncooked fruit and vegetables (including salads) that have not been washed with bottled or boiled water and prepared yourself
  • Bo not eat shellfish and seafood
  • Do not eat ice cream or have ice in your drinks5

When to consider vaccination?

The vaccine is not indicated for most travellers, but can be recommended for those whose activities or medical history puts them at increased risk. This includes:

  • Aid workers
  • Those going to areas of cholera outbreaks who have limited access to safe water and medical care
  • Those for whom vaccination is considered potentially beneficial
  • Laboratory workers who may be regularly exposed to cholera in their work6

Vaccination

The cholera vaccine is available as an inactivated oral vaccination and is thiomersal-free. The course of vaccinations should be finished at least 1 week before travel.6

For adults, 2 doses (given 1 to 6 weeks apart) can provide protection for up to 2 years. A reinforcing dose is given after 2 years.

Young children require 3 doses of vaccine to establish effective immunity.6

The vaccine does not provide complete protection. For example, it does not protect against all strains of cholera. Therefore, it is still important to take precautions with food, water and personal hygiene.4

References

This information is taken from trusted third party websites, NaTHNaC (Travel Health Pro) and EMIS (Patient info) and use of all information has been licenced under the Open Government Licence http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/.

Although the materials are being used/replicated under the provisions of the Open Government Licence this in no way represents endorsement of Traveljab.co.uk by NaTHNaC, Emis, Public Health England, the NHS or the Department of Health and Social Care.

  1. Travel Health Pro (NaTHNaC) – Cholera
  2. WHO maps – Cholera, areas reporting outbreaks 2010 – 2014
  3. Travel Health Pro – Country information
  4. patient.info – Cholera and Cholera vaccination
  5. NHS – Cholera
  6. The Green Book – Chapter 14: Cholera