Humanitarian emergencies

What actions are most urgent in relation to water, sanitation and health?

The three top priorities are the provision of sufficient quantities of safe water, basic sanitation arrangements and promotion of good hygiene behaviours.

The first priority is to provide an adequate quantity of water, even if its safety cannot be guaranteed, and to protect water sources from contamination. A minimum of 15 litres per person per day should be provided as soon as possible, though in the immediate post-impact period, it may be necessary to limit treated water to a minimum of 7.5 litres per day per person. During emergencies, people may use an untreated water source for laundry, bathing, etc. Water-quality improvements can be made over succeeding days or weeks.

Major health risks due to inadequate excreta disposal arise after disasters. Where normal sanitation structures have been damaged or destroyed it is essential to provide toilet facilities immediately. Emergency facilities are usually provisional and need to be progressively improved or replaced as the situation develops.

Following damage to existing systems, or when parts of a city receive large numbers of displaced or homeless people, so putting increased pressure on facilities that may already be under strain, a rapid assessment of damage and needs is required to decide what emergency actions to take.

Designated defecation fields or areas can be used where enough space is available. These work best in hot, dry climates and should be clearly marked, fenced (if possible), and protected against flooding. They should be located downwind and away from living areas, avoid water courses, and at a reasonable distance (minimum 50m) from water points. Shovels should be provided to families so that they can dig small holes to defecate into and cover their faeces with soil. Collective trench latrines may also be an option. In longer term situations or after the initial emergency period has subsided, it may be more practical to build simple pit latrines, ventilated improved pit (VIP) latrines, or poor-flush latrines. In situations where the soil is rocky or the ground water is very close to the surface, elevated platforms may be constructed. Latrines of all types need to be properly cleaned and maintained. Responsibilities for cleaning and maintaining latrines should be clearly spelled out. For collective latrines it may be necessary to hire someone to take care of them.

The immediate response may also include establishing or reinforcing sewage evacuation services, to bypass blocked sewers or to carry out intensive septic tank or latrine emptying in periurban areas. Every effort should be made to allow people to use their existing toilets, through temporary repairs to broken sewers and sewage treatment works.

In all cases, good hygiene practices are very important for preventing disease transmission. Water should be provided in sufficient quantities to enable proper hygiene. Hands should be washed immediately after defecation, after handling babies' faeces, before preparing food and before eating.

Other environmental health interventions might be crucial as indicated in the subsequent questions and answers.

What water, sanitation and hygiene behaviours are most important for protecting health during an emergency?

• Make every effort to drink water which has been disinfected (preferably filtered and disinfected) or boiled. Protect water sources from contamination.
• Dispose of faeces safely (especially the faeces of babies and people with diarrhoea) in latrines or special areas that will not lead to exposure of community members or contamination of water sources (surface or ground water).
• Wash hands thoroughly with soap, after defecation, after handling babies' faeces, and before preparing or eating food.

What are the greatest drinking-water and sanitation dangers to human health, and who are the most vulnerable groups?

Infectious disease transmission is the greatest risk after an emergency. The diseases and conditions of ill-health directly associated with water, sanitation and hygiene include infectious diarrhoea (which, in turn, includes cholera, salmonellosis, shigellosis, amoebiasis and a number of other protozoal and viral infections), typhoid and paratyphoid fevers, acute hepatitis A, acute hepatitis E and F, schistosomiasis, trachoma, intestinal helminth infections (including ascariasis, trichuriasis and hookworm infection), dracunculiasis, scabies, dengue, leptospirosis, the filariases (including lymphatic filariasis and onchocerciasis), malaria, Japanese encephalitis, West Nile virus infection, yellow fever and impetigo. Not all these diseases are relevant to all the affected countries. The spread of most of these diseases is of special concern where sanitation systems are disrupted and where excreta has been distributed widely by flooding. The most vulnerable groups are children under five and the elderly. About 90 per cent of the deaths due to diarrhoea occur in children under 5.

Although infectious diseases will pose the greatest health risks, in some cases toxic chemicals may enter water supplies, especially when there has been massive flooding.

Drinking water sources away from sources of chemical or microbial contamination should be used as supplies. If this is not possible, alternative supplies of water may be required (e.g., bottled water or supplies through tanker trucks).

Are there any risks which may become increasingly acute as the time since a disaster evolves?

The length of time that people spend in temporary settlements is an important determinant of the risk of disease transmission which might lead to major epidemics. The prolonged mass settlement of in temporary shelters with only minimal provision for essential personal hygiene is typical of a situation that may cause epidemic outbreaks of infectious diseases.

The main risks of epidemics come from unsanitary conditions and can include, for example, typhoid, dysentery, cholera, and diarrhoea. Leptospirosis may also be transmitted through contaminated water or food stuffs that have been contaminated by the urine of infected rats or other animals. Diseases related to overcrowded conditions such as respiratory infections, typhus, and infestations from scabies and lice are also of concern. Diseases spread through mosquito vectors such as malaria, dengue, and Japanese encephalitis may also arise when disease vectors are allowed to breed in stagnant water or even standing water in old tires, cans, etc. Communities may be especially vulnerable to vector-borne diseases when they are living without shelter or access to bed nets.

• Emergency health action programme for South Asia

Based on estimates of requirements of lactating women who engage in moderate physical activity in above-average temperatures, a minimum of 7.5 litres per capita per day will meet the requirements of most people under most conditions. This water needs to be of a quality that represents a tolerable level of risk. However, in an emergency situation, a minimum of 15 litres is required. A higher quantity of about 20 litres per capita per day should be assured to take care of basic hygiene needs and basic food hygiene. Laundry/bathing might require higher amounts unless carried out at source.

• Domestic water quantity, service level and health

What are good indications that water is safe?

In an emergency it should be assumed that all water is at risk of contamination and this includes piped supplies. Thus until told by authorities or having inspected and tested the water it should ideally be treated.

The quality of urban drinking-water supplies is particularly at risk following structurally damaging disasters. Water treatment works may be damaged, causing untreated or partially treated water to be distributed, and sewers and water transmission pipes may be broken, causing contamination of drinking-water in the distribution system.

Floods may contaminate wells, boreholes and surface water sources with faecal matter washed from the ground surface or from overflowing latrines and sewers.

Where there is evidence of faecal contamination of the drinking-water supply, it may be necessary either to modify the treatment of existing sources or to temporarily use alternative sources of drinking-water. It may be necessary to increase disinfection at source or to rechlorinate during distribution. In emergencies, such as during outbreaks of potentially waterborne disease or when faecal contamination of a drinking-water supply is detected, the concentration of free chlorine should be increased to greater than 0.5 mg/litre throughout the system as a minimum immediate response.

• WHO Guidelines for drinking-water quality

Should all water used for domestic purposes be treated?

Not necessarily. However, if you do no have the assurance from the local health agencies or the water utilities that the water is safe then you should disinfect it using one of the different home water treatment methods available.

• Household Water Treatment and Safe Storage Following Emergencies and Disasters

Are there disease risks from dead bodies and what should be done for safe disposal?

The widespread belief that corpses pose a major health risk is inaccurate. Especially if death resulted from trauma, bodies are very unlikely to cause outbreaks of diseases such as typhoid fever, cholera or plague though they may transmit gastroenteritis or food poisoning syndrome for survivors if they contaminate streams, wells or other water sources.

• Disposal of dead bodies
  

• Mortuary service and handling of the dead (from Environmental health in emergencies and disasters)

What are the health risks related to overcrowding?

For communities, inadequate shelter and overcrowding are major factors in the transmission of diseases with epidemic potential such as acute respiratory infections, meningitis, typhus, cholera, scabies, etc. Outbreaks of disease are more frequent and more severe when the population density is high.

Other public structures such as health facilities not only represent a concentrated area of patients but also a concentrated area of germs. In an emergency, the number of hospital-associated infections will typically rise. Decreasing overcrowding by providing extra facilities and a proper organization of the sites or services in health-care facilities is a priority.

What are the health risks related to stagnant water?

Pools of standing or slow-flowing water provide a breeding ground for many insects, including mosquitoes that can transmit diseases. These mosquitoes are known as vectors. Different species of mosquitoes transmit different diseases, and they will also breed in different types of water collections. In the context of the tsunami disaster, the key water-associated vector-borne diseases are malaria and dengue, with possibly and more speculatively Japanese encephalitis in very local conditions.

Are there different health risks linked to fresh and brackish (salty) water?

All malaria transmitting mosquitoes belong to the genus Anopheles which breeds exclusively in fresh, clean water, with the exception of Anopheles sundaicus, which breeds in brackish water. The original distribution of Anopheles sundaicus is linked to its natural habitats of mangrove forests and coastal lagoons. It starts in eastern India (but not as far south as Tamil Nadu) then along the coasts of Bangladesh, Myanmar, Thailand, Malaysia, Indonesia and Viet Nam. Organically polluted water does not support the breeding of the malaria vector; rather it helps propagate Culex quinquefasciatus, in some parts a vector of lymphatic filariasis, and a main nuisance mosquito. In the context of this disaster lymphatic filariasis is however not a disease of immediate relevance due to its long incubation period.

Where is the risk of malaria most acute and what should be done?

There is no malaria in the Maldives and along the coastline of Southern Thailand; malaria in South India is limited to urban areas; thus the main risk areas are Sri Lanka, Myanmar and Indonesia. In Sri Lanka, risks will increase when brackish water is washed out by monsoon rains and the floods recede: An. culicifacies will start breeding in the remaining pools. In Myanmar and in northern Sumatra the evolution of malaria risks in relation to floods and flood recession is less clear.

Important measures include:

• Personal protection, using insecticide treated mosquito nets, and impregnation with insecticides of all material for temporary shelter (such as tents); spraying with residual insecticides will only be feasible where housing structures are still intact.
• Making available mosquito repellents to affected populations to re-inforce personal protection using nets or other impregnated materials
• Access to anti-malaria drugs linked to effective monitoring of the start of outbreaks

Where is the risk of dengue fever most acute and what should be done?

The viruses that cause dengue fever and dengue haemorrhagic fever are transmitted by the mosquito Aedes aegypti, and in Asia to a lesser extent by Ae. albopictus. Aedes aegypti breeds mainly in water collections in artificial containers in the environment of human settlements, but not in groundwater pools and puddles, nor in swamps or other large natural bodies of water. Effective prevention and control of epidemic dengue requires control of vectors. No vaccine exists for dengue..

Prevention of mosquito-breeding in drinking-water containers, by covering them to exclude mosquitoes, frequently emptying them (at least once per week), or treating them with insecticide, e.g., temephos 1% sand granules, will contribute to the prevention of dengue outbreaks. However, this may not be sufficient in settlement areas where there are small, freshwater collections in other artificial containers and miscellaneous debris. Depending on feasibility, chemical larvicides may also be applied under these conditions. Portable equipment for space spraying will be needed in areas with difficult road access. To the extent possible, affected populations may be provided with mosquito repellents.

Source reduction is the mainstay of dengue prevention. This should be backed up by chemical control whenever mosquito populations expand rapidly.

• Dengue in the Sout-East Asia

Where is the risk of Japanese Encephalitis most acute and what should be done?

The risk of Japanese encephalitis (JE) outbreaks is less than malaria and dengue and restricted to Sri Lanka. When large stretches of flooded area are washed out by monsoon rains and turn into freshwater, populations of the mosquitoes Culex tritaeniorrhynchus and Culex gelidus (vectors of JE) may rapidly build up, and may start biting humans (instead of their normal hosts of - domestic animals - which will have been decimated by the disaster). In normal circumstances, pigs are the amplifying hosts of the JE virus; in this emergency situation, direct transmission from herons and similar birds to humans cannot be excluded.

Measures:

• vaccination of vulnerable groups (children) in areas at risk;
• personal protection from mosquito bites through the use of insecticide treated mosquito nets
• use of insect repellents

Water

What are the options of getting safe water to people in affected areas?

If water is deemed by local authorities to be unsafe, bottled water may need to be distributed or clean water transported by tanker truck to distribution points to meet immediate needs. Alternative temporary water sources and treatment plants may sometimes be available from dairies, soft-drink bottling plants, or breweries.

How can water be most effectively treated at household level and on a large scale?

If safe water cannot be supplied, it is critical to communicate to families that they need to treat water themselves, at home. Household water treatment is effective, simple, and inexpensive. It is especially applicable to populations recovering from a disaster situation who often lack facilities and resources. Following emergencies, chlorine or iodine tablets, or sachets of combined flocculant/disinfection powder may have been distributed. If this is the case, water should be treated using the directions that come with the tablets. If household bleach or other sources of chlorine are available, water may be disinfected with a dilute chlorine solution. Solar disinfection is an effective water treatment method that is applicable to emergencies, especially when no chemical disinfectants are available. Ultra-violet rays from the sun are used to inactivate pathogens present in water. This technique involves exposing water in clear plastic bottles to sunlight for a day, for example on the roof of a house. In emergencies, empty bottles can be used that are left over from an initial shipment of drinking water. Another option to treat water at home is to use of simple ceramic pot filters.

Hygiene

How can personal hygiene be maintained in difficult circumstances?

Despite water shortage and restricted sanitation facilities in emergency situations, it's critical to ensure that some of the available water supply is used for personal hygiene to minimize health risks. Messages about the importance of handwashing with soap at critical times-i.e. after defecation, after handling babies faeces, and before preparing food-are particularly important. As soap may be in short supply during emergencies, the use of ash, sand, or other culturally acceptable substitutes should be promoted.

Sanitation

What should people who have no access to sanitation facilities do and how can you minimize risk?

Where normal sanitation structures have been damaged or destroyed it is essential to provide toilet facilities immediately. Emergency facilities are usually provisional and need to be progressively improved or replaced as the situation develops.

Designated defecation fields or areas can be used where enough space is available. These work best in hot, dry climates and should be clearly marked, fenced (if possible), and protected against flooding. They should be located downwind and away from living areas, avoid water courses, and at a reasonable distance (minimum 50m) from water points. Shovels should be provided to families so that they can dig small holes to defecate into and cover their faeces with dirt. Collective trench latrines may also be an option. In longer term situations or after the initial emergency period has subsided, it may be more practical to build simple pit latrines, VIP latrines, or poor-flush latrines. In situations where the soil is rocky or the ground water is very close to the surface elevated platforms may be constructed.

As a general rule, individual family latrines are preferred, are more socially acceptable and can be maintained by the family. If necessary, centralized toilet facilities can be built at the edge of a living quarter or camp section where each family has access to their own latrine. The area allowed for latrines should be big enough to dig new pits when the first ones are full. Latrines of all types need to be properly cleaned and maintained. Responsibilities for cleaning and maintaining latrines should be clearly spelled out. For collective latrines it may be necessary to hire someone to take care of them.

In all cases, good hygiene practices are very important for preventing disease transmission. Clean water should be provided in sufficient quantities to enable proper hygiene. Hands should be washed immediately after defecation, after handling babies' faeces, before preparing food and before eating.

Is waste management a priority in such precarious situations?

The accumulation of waste, especially in urban and peri-urban like situations because of their high population density, creates public health risks through the presence of insect or rodent vectors of diseases. Breeding of flies plays a major role in the transmission of faeco-oral diseases as flies are vectors that carry pathogens. Rodents are directly or indirectly responsible for the transmission of diseases such as plague, leptospirosis and salmonella. Water in empty tins, tyres, etc., may be a breeding site for Aedes mosquitoes responsible for the transmission of dengue and yellow fevers and other arboviruses. Inadequate waste management may cause the pollution of surface and groundwater and increase the risk of fire. Medical wastes represent a particular risk as they are infectious, and therefore need special attention. As much as possible waste should be disposed of by on-site burying, brought to a defined landfill, or incineration if no better options are available.

• Health-care waste management

What has WHO done to improve access to safe water, sanitation and hygiene situation?

This is the latest updated as of 7th January 2005. The World Health Organization is updating information on water, hygiene and sanitation on a regular basis. For latest updates in countries on water, sanitation and hygiene visit:

• WHO situation reports

WHO's overriding concern remains of potential associated disease outbreaks throughout the region. With isolated cases of diarrhoeal disease confirmed in temporary shelter camps in India and Sri Lanka, focus must be on improving hygienic and sanitation conditions for the estimated 3-5 million displaced people. Cases of diarrhoea are reported and are under scrutiny for the possibility of cholera and typhoid. Of particular concern is that the situation throughout the region is ripe for cholera cases, a disease not unknown to the region. Lack of adequate clean drinking water and sanitation facilities, stress and psychosocial trauma and overcrowding in camps contributes to heighten the risks of disease outbreaks. Relief efforts are now well on the way, but concerted coordinated action among all health actors is required.