Cholera

Rapidly responding to cholera in north-eastern Nigeria

WHO/C. Onuekwe

30 August 2017 - WHO and partners are moving swiftly to help authorities contain a cholera outbreak in a camp for internally displaced people in north-eastern Nigeria. A total of 69 cases have been reported in a camp on the outskirts of the state capital Maiduguri, which is home to 44 000 people displaced by conflict and famine.

Cholera count reaches 500 000 in Yemen

14 August 2017 – The total number of suspected cholera cases in Yemen this year hit the half a million mark on Sunday, and nearly 2000 people have died since the outbreak began to spread rapidly at the end of April. The spread of cholera has slowed significantly in some areas compared to peak levels but the disease is still spreading fast in more recently affected districts, which are recording large numbers of cases.

Oral cholera vaccine

Since the creation of the global stockpile in 2013, more than 5 million doses of oral cholera vaccine (OCV) have been successfully used in various outbreaks and humanitarian emergencies. The use of oral cholera vaccines is an additional tool to the classic cholera control measures. It should be systematically considered in both endemic countries as well as during outbreaks and emergencies.

Ongoing battle against cholera in Democratic Republic of the Congo

As cholera spread along the Congo River and reaches Kinsasha, capital of Democratic Republic of the Congo, increasing numbers of people are sick and at-risk. With WHO's support, the provincial ministry of health of Kinshasa launched a vaccination campaign to help contain this outbreak. Watch the video and know more about this ongoing battle against cholera in Democratic Republic of the Congo.

Revised cholera kits

Cholera treatment centre in Zilmbabwe
WHO/D. Legros

The composition of the cholera kits has been reviewed by WHO and its partners. The contents of all modules have been updated and reorganised to be better adapted for field use in different settings.

The revised cholera kits are designed to help prepare for a potential cholera outbreak and to support the first month of the initial response. The overall package consists of six different kits, each divided in several modules. The kits and modules can each be ordered separately.

The Global Task Force on Cholera Control (GTFCC)

A young ...
WHO

The 2011 WHA 64.15 resolution “Cholera mechanisms for control and prevention” requested the WHO Director-General to revitalize the Global Task Force for Cholera Control (GTFCC) and to strengthen WHO’s work in this area, including improved collaboration and coordination among relevant WHO departments and other relevant stakeholders.

A revitalization process has been initiated in December 2012 and completed in early 2014. Terms of Reference have been agreed and are accessible below.

Cholera is an acute diarrhoeal infection caused by ingestion of food or water contaminated with the bacterium Vibrio cholerae. Cholera remains a global threat to public health and an indicator of inequity and lack of social development. Researchers have estimated that every year, there are roughly 1.3 to 4 million cases, and 21 000 to 143 000 deaths worldwide due to cholera.

Cholera is an extremely virulent disease that can cause severe acute watery diarrhoea. It takes between 12 hours and 5 days for a person to show symptoms after ingesting contaminated food or water. Cholera affects both children and adults and can kill within hours if untreated.

Most people infected with V. cholerae do not develop any symptoms, although the bacteria are present in their faeces for 1-10 days after infection and are shed back into the environment, potentially infecting other people.

Among people who develop symptoms, the majority have mild or moderate symptoms, while a minority develop acute watery diarrhoea with severe dehydration. This can lead to death if left untreated.

The presence of V. cholerae in stools is confirmed through laboratory procedures. However, a new rapid diagnostic test (RDT), now available, allows quick testing at the patient's bedside. WHO is currently in the process of validating this RDT, to be able to include it on the list of its pre-qualified products.

In the meantime, WHO suggests that all samples tested positive with the RDT are re-tested using classic laboratory procedures for confirmation. Not all cases fitting the WHO clinical case definition need to be tested. Once an outbreak is confirmed, a clinical diagnosis using WHO standard case definition is sufficient1, accompanied by sporadic testing at regular intervals.

Cholera is an easily treatable disease. The majority of people can be treated successfully through prompt administration of oral rehydration solution (ORS). The WHO/UNICEF ORS standard sachet is dissolved in 1 litre (L) of clean water. Adult patients may require up to 6 L of ORS to treat moderate dehydration on the first day.

Severely dehydrated patients are at risk of shock and require the rapid administration of intravenous fluids. A 70 kg adult will require at least 7 L of intravenous fluid, plus ORS during their treatment. These patients are also given appropriate antibiotics to diminish the duration of diarrhoea, reduce the volume of rehydration fluids needed, and shorten the amount and duration of V. cholerae excretion in their stool.

Mass administration of antibiotics is not recommended, as it has no proven effect on the spread of cholera and contributes to increasing antimicrobial resistance.

Rapid access to treatment is essential during a cholera outbreak. Oral rehydration should be available in communities, in addition to larger centres that can provide intravenous fluids and 24 hour care. With early and proper treatment, the case fatality rate should remain below 1%.

Currently there are 3 WHO pre-qualified oral cholera vaccines: Dukoral®, Shanchol™, and Euvichol®. All 3 vaccines require 2 doses for full protection.

Dukoral® is administered with a buffer solution that, for adults, requires 150 ml of clean water. As access to clean water is often limited in areas with cholera epidemics, Dukoral® is mainly used for travellers. Dukoral® provides approximately 65% protection against cholera for 2 years.

Shanchol™ and Euvichol® are essentially the same vaccine produced by 2 different manufacturers. They do not require a buffer solution for administration, which makes them easier to administer to large numbers of people in emergency contexts. There must be a minimum of 2 weeks delay between each dose of these 2 vaccines. However, 1 dose of vaccine will provide some protection with the second dose given at a later date.

Individuals vaccinated with Shanchol™ or Euvichol® have approximately 65% protection against cholera for up to 5 years following vaccination in endemic areas. The reduced circulation of V. cholerae bacteria in the population due to the reduced number of people with cholera further reduces cholera in the population. This additional protection is called herd protection.

In 2013, WHO established a stockpile of 2 million doses for use in outbreak control and emergencies. The stockpile is managed by the International Coordinating Group (ICG) made up of the International Federation of Red Cross and Red Crescent Societies, Medecins Sans Frontieres, UNICEF, and WHO.

For non-emergency settings, vaccines are available via the Global Task Force on Cholera Control (see WHO response section below). In these contexts, oral cholera vaccines (OCVs) are used as part of a longer-term cholera control plan including reinforcement of other aspects of cholera control. In eligible countries, financial support for vaccines is provided by Gavi, the Vaccine Alliance.

WHO is currently responding to major cholera outbreaks around the world, particularly in the Democratic Republic of the Congo, Haiti, the Horn of Africa, Mozambique, South Sudan and Yemen.

WHO adapts its response to the local context, but the core response is to work with Ministries of Health , local partners and international networks such as GOARN to provide medical supplies, including oral rehydration solutions, IV fluids, cholera kits as well as rolling out OCV campaigns. WHO support strengthening of disease surveillance and investigation through the deployment of rapid response teams, training community health workers to conduct house-to-house case identification, and referral to cholera treatment centres. Much of this is supported by community mobilization and engagement. While the creation of an oral cholera vaccine stockpile has contributed significantly to cholera control, the preventive effect of vaccination is greatest when combined with improvements in water and sanitation, and WHO strongly advocates for combined interventions.


Epidemiological information

Technical information

General information

Revised cholera kit

The revised cholera kits are designed to help prepare for a potential cholera outbreak and to support the first month of the initial response.

Contact us

For any request please send us an email to: csr@who.int