Cholera is an epidemic faecal-oral disease caused by the bacterium Vibrio cholerae entering the body through the consumption of contaminated water and/or food, due to poor water and sanitation systems and inappropriate hygienic practices. It infects the small intestine leading to severe watery diarrhoea, rapid dehydration and death if left untreated. Most infected people do not develop any symptoms. They can, however, spread cholera further if water sources become contaminated with faeces containing the bacterium, usually when hygiene conditions are poor and open defecation is prevalent.
There are many ways to prevent and control the spread of cholera requiring actions within the health sector and beyond, including ensuring access to safe water, sanitation and good hygiene practices (WASH). Some countries suffer from endemic cholera and experience frequent outbreaks, which are mostly seasonal. Others can experience occasional outbreaks but these are not necessarily endemic. Both require an emergency response, but do not necessarily result in a humanitarian crisis.
However, in most cases, cholera outbreaks impact nations/regions already dealing with a pre-existing fragile context, including poor hygienic conditions and limited access to drinking water and sanitation facilities. Although the focus here will mainly be on cholera in emergencies, it is important to recognise that wherever possible, efforts to control cholera should seek to build long-term systems and consider long-term prevention beyond reactive approaches. Targeting multisectoral interventions in cholera hotspots is also a key point in the Global Task Force on Cholera Control (GTFCC) roadmap. According to the roadmap, interventions should include strengthening surveillance (of outbreaks) and health systems and the implementation of sustainable, long-term WASH solutions alongside the promotion of strong community engagement and cross-border collaboration.
Relevant WASH and Infection Prevention and Control (IPC) Interventions
The provision of WASH services is a key element of both the prevention of and response to cholera outbreaks. In cholera endemic and risk prone areas, efforts must be made to ensure safe and adequate water supply and disinfection, water quality monitoring X.7, hygiene promotion X.16 and sanitation and safe excreta disposal at household and community level, in healthcare facilities or in special units called Cholera Treatment Centres or Units (CTCs/CTUs). In terms of water supply, the focus should be on the following:
Ensuring sufficient and safe drinking water at the point of consumption: Water is needed for drinking, preparing oral rehydration solution (ORS), washing (hands, body, laundry), cleaning/disinfection, cooking, toilets and preparing dead bodies for burial. In CTCs, at least 60 L per patient and 15 L per caregiver of chlorine-treated water should be available per day. Water for drinking and washing (e.g. hands, food), and other purposes, needs to be treated to a free residual chlorine (FRC) level of at least 0.5 mg/L at pH < 8.0 after 30 minutes of contact time, 1.0 mg/L at the water source and a minimum of 0.5 mg/L at the point of delivery. Treated water should be delivered in separate and clearly marked containers.
Overall, it is necessary to consider treatment before providing water to the user (both in rural/low-density areas and urban areas where contaminated piped water may be prevalent) and ensuring safe storage H.1 and preventing (re-)contamination at the point of consumption. This requires hygiene promotion interventions X.16, where information is provided on safe water collection, transport, handling and storage, safe use of cups and dishes, handwashing, etc. Household water treatment options like Ceramic or Membrane Filtration H.3 , H.4 , Point-of-Use Chlorination H.6 or Boiling H.9 may require behavioural changes for people who do not have prior experience with the technology. Therefore, the introduction of household water treatment methods must be combined with respective hygiene promotion activities to ensure safe water at the point of use.
Latrines and bathing units: These should be available in sufficient numbers and at a suitable distance from water sources (see Sphere for further guidance). In CTCs, one latrine can serve up to 20 people in the observation and recovery area and up to 50 in hospitalisation, and one or two latrines should serve the staff. Newly constructed latrines should be connected to a septic tank at least 30 m away from the next water source. One bathing or shower unit for a maximum of 50 people should be considered. Both latrines and bathing units should be gender separated and adapted to local customs and specific needs of elderly, pregnant women or people with disabilities, and functional handwashing facilities need to be installed next to latrines.
Preventing the contamination of water sources and the environment: Faecal matter needs to be kept away from human contact, water and food. This containment is done by providing functioning, accessible, appropriate and safe toilets for affected communities (as well as staff, patients and caregivers) that do not contaminate the healthcare setting or water supplies. The entire sanitation service chain must be designed (see Compendium of Sanitation Technologies in Emergencies) to ensure proper collection, transport, treatment and safe disposal or reuse. Furthermore, hygiene promotion X.16 is necessary to ensure that people prioritise the importance of cleanliness of the environment and act out healthy behaviours.
Handwashing: Handwashing facilities H.2 with soap and clean (chlorinated) water must be available and accessible, and proper handwashing practices must be promoted, particularly at key times (before cooking, eating and feeding and after latrine use or cleaning a child’s bottom). For healthcare workers, handwashing is necessary before (1) touching a patient and (2) performing cleaning procedures, and after contact with (3) the patient, (4) body fluids (or risk of contact) and (5) their surroundings. The water for handwashing must be safe, and soap should always be used. Alternatives are Alcohol-Based Hand Rub (ABHR) or water treated with a 0.05% chlorine solution where soap is not available.
Isolation of patients: Every cholera case should be investigated to assess and break the chain of transmission. Suspected and confirmed cholera patients should be isolated from other patients and treated in CTCs to prevent the spread of the disease in the community and prevent deaths. Cholera may also be treated in health centres and isolation units of hospitals, especially at the beginning of the outbreak when CTCs are not yet established.
Personal Protective Equipment (PPE): For cholera outbreaks, appropriate PPE needs to be provided and used if there is a chance of contact with body fluids of any kind. This includes waterproof gowns (or if not available: waterproof aprons), mask and goggles, boots and gloves. The use of PPE is of particular importance for personnel involved in cleaning, waste management and using/preparing high-strength chlorine solutions.
Food hygiene: Food hygiene is essential and includes proper preparation (cooking raw food thoroughly and heating it to >70°C, washing vegetables with soap and safe water, peeling fruit and vegetables), eating food immediately while it is still hot, reheating it thoroughly (once only), safe food storage and cleaning of cooking utensils (cutting boards, utensils and dishes with soap and safe water). After use, surfaces used for preparation and eating and cooking utensils as well as food containers need to be washed with detergent and a 0.2% chlorine solution. Different utensils should be used for raw and cooked foods.
Laundry: Protective clothing as well as the patient’s clothes, blankets, gowns and staff uniforms should be washed with a 0.2% chlorine solution for 10 minutes. These should then be washed in water with detergent and air-dried in sunlight, when possible.
Safe and dignified burials and burial preparation: If someone dies of cholera (or a condition suspected to be cholera), trained personnel should be asked to assist with a safe and proper burial. The body needs to be disinfected by people wearing PPE and carried in body bags or cloths soaked with 2% chlorine solution. Funeral participants need to be made aware of the risks during the funeral, if necessary, and variations to traditional rituals may need to be discussed. Direct physical contact must be avoided. If unacceptable, PPE should be worn, and hands should be washed immediately after contact. The burial site or cemetery should be at least 50 m away from water sources and at least 1.5 m deep. No food should be served during the funeral. In case it is served, it needs to be hot, and hand hygiene must be enforced.
Cleaning and disinfection: The appropriate chlorine solutions must be available for each required purpose, and these solutions differ in their required percentages of FRC: (1) 0.05% for hand disinfection when neither soap nor ABHR are available. (2) 0.2% for disinfecting entire cholera wards, including (affected) latrines and bathing units, the laundry area, kitchen and morgue. Additionally, beds and cots, bedding and linen, PPE, waste containers and covers, food utensils, food containers and dishes and vehicles used for patient transport should also be treated. (3) 2% to add to highly infectious excreta and vomit from cholera patients for disinfection and to wash dead bodies (or alternatively lime treatment).
WASH- and IPC-related cholera relief interventions can be broadly distinguished between households, institutions, and CTC/CTU facilities.
Risk of contamination is particularly high in household settings, and members of households of cholera patients are 100 times more at risk of contracting the disease than other community members.
Cholera Treatment Centres/Units
A thin, pliable sheet or layer of natural or synthetic (filter) material.Protective equipment (e.g. clothing, helmets, goggles) designed to protect the wearer from injury or infection.Stands for power of hydrogen; a scale used to specify how acidic or basic (alkaline) a waterbased solution is. A pH value below 7 indicates that a solution is acidic, and a pH value above 7 indicates that it is basic (alkaline).
UNICEF (): Cholera Toolkit UNICEF, New York. USA
WHO et al. (): Cholera Central Reference Kit WHO, Geneva. Switzerland
WHO (): Cholera: Revised Cholera Kits and Calculation Tool WHO, Geneva. Switzerland
GTFCC (2020): Cholera Outbreak Response Field Manual Global Task Force on Cholera Control
GTFCC (2017): Ending Cholera. A Global Roadmap to 2030 Global Task Force on Cholera Control