Contaminated water is one of the most significant factors which contribute to the high morbidity and mortality from infectious diseases in developing countries. Contaminated water supplies have the potential to cause large and explosive epidemics (e.g., cholera). The non-availability of specific treatment for viral diseases such as hepatitis and the increasing problem of antibiotic resistance, which makes bacterial diseases such as typhoid and dysentery more difficult to treat, underline the importance of preventing water-borne disease through effective hygiene. Water often becomes contaminated during distribution or transport to the home, and during storage and handling within the home.
Among the main problems which are responsible for this situation are: lack of priority given to the sector, lack of financial resources, lack of sustainability of water supply and sanitation services, poor hygiene behaviors, and inadequate sanitation in public places including hospitals, health centers and schools. Providing access to sufficient quantities of safe water, the provision of facilities for a sanitary disposal of excreta, and introducing sound hygiene behaviors are of capital importance to reduce the burden of disease caused by these risk factors.
The availability of water is essential for water hygiene and naturally, an easy accessible water source facilitates the practice. But to ensure that water hygiene is practiced daily the water source must be reliable both in quantity and quality throughout the year. Problems of poor water quality or low quantity discourage improved hygienic behaviors. E.g., in areas with corrosion problems community members often prefer to use the traditional water sources, as the brownish-yellow colour and the taste of the improved water source are less attractive. An improved water source can be contaminated if poorly maintained. The motivation of the community to maintain and protect their water source is, therefore, of critical importance to ensure a sustainable reduction in not only water borne diseases, but also to prevent an increase in the incidence of water-related vector-borne diseases, due to breeding of mosquitoes in stagnant water around the water source. As all water-borne and faecal-disposal-related diseases, as well as some water-based diseases, depend on infecting agents from human excreta, the provision and hygienic use of adequate sanitation are crucial for their control. Finally proper refuse disposal is important for the control of some faecal-oral and vector-related water-borne diseases, as it prevents the breeding of insects.
Water-borne diseases transmitted by water. Water is a passive transporter for the infective agent, e.g., diarrhoea, dysentery, typhoid, giardiasis, cholera. Water-washed diseases due to lack of water or insufficient use of water for personal or domestic hygiene, e.g., trachoma. Water-related vector-borne diseases transmitted by insects breeding or biting in relation to water, e.g., malaria, onchocerciasis. Water-based diseases caused by infecting agents spread by contact with or ingestion of water. An essential part of the life cycle of the infecting agent takes place in an aquatic animal, e.g., schistosomiasis and Guinea worm. Faecal-disposal-related diseases transmitted due to faecal contamination of soil. Human infection is either through direct penetration of the intact human skin (e.g., hookworms) or through ingestion, either with an intermediate host (e.g., tapeworm) or without (e.g., roundworm).
- The control of waterborne diseases requires a safe water source of a high quality and with enough water for the practice of general water hygiene, which will ensure that the water stays safe.
- The control of water-washed diseases depends on easy access to large quantities of water and the motivation to use more water for personal hygiene, whereas the quality of the water used is less important.
- The control of vector-related water-borne diseases depends on improved environmental hygiene and decreased exposure to the vector.
- The control of water-based diseases depends on elimination of contact with the infected water source.
To reduce the risks from water borne disease people must be:
- Informed and aware about the source and the quality of their water, since this can vary significantly between different communities
- Educated on how to handle, store, test quality periodically and, if necessary, treat water in their own homes.
There are three key actions needed to prevent waterborne disease:
- Families and communities need to protect their water supply against contamination
- Families need to keep water clean in the home
- Families may need to treat water to make it safe for drinking and other uses.
Protecting the water supply
- In communities where there is no piped water supply, people have to rely on other sources of water such as bore wells and springs
- Communities should be made aware of the importance of protecting their water supply, encouraged to take responsibility for the supply, and instructed on how to do this.
Families and communities can protect their water supply by:
- Keeping wells covered and installing a hand-pump
- Disposing of faeces and waste water well away from any water source used for cooking, drinking and washing
- Building latrines at least 15 metres away and downhill from a water source
- Keeping buckets, ropes and jars used to collect and store water as clean as possible by storing them in a clean place rather than on the ground
- Keeping animals away from drinking water sources and family living areas
- Avoiding the use of pesticides or chemicals anywhere near a water source
- Sanitary Inspection of water sources & water quality testing should be undertaken periodically.
Keep water clean in the home
- Water vessels and tanks must be clean and kept covered
- During collection and storage, do not allow anyone to put their hands into the water or drink
- Directly from the storage vessel or tank If possible water storage vessels should have a narrow neck and a tap at the bottom so that hand contact is not possible Otherwise take water out of the vessel with a clean ladle or cup
- Do not continually top up the water in storage vessels. After each use vessels must be Thoroughly rinsed with potable or treated water
- Storage tanks should be regularly cleaned and disinfected
- Keep animals away from stored water
- Water in storage vessels should be stored in the home for the shortest possible time.