|Hygiene Evaluation Procedures - Approaches and Methods for Assessing Water- and Sanitation-Related Hygiene Practices (International Nutrition Foundation for Developing Countries - INFDC, 1997, 124 pages)|
|1. What is the HEP?|
For a long time, project planners have appreciated the value of improving water supply and sanitation facilities. Improved facilities reduce contamination of drinking water and of the environment, and reduce diarrhoeal disease transmission and worm infestations. Even so, World Health Organization and World Bank statistics show that as many as three million children still die from intestinal infections every year, and a third of the world's population is still infected with parasites. The main reason for this is not that too little has been invested in technological improvement of facilities, but that the facilities are often inappropriate, unaffordable, or unacceptable to the intended users. All of these result in no use, limited use, or inappropriate use of facilities.
For example, pit latrines are widely promoted in both urban and rural regions in many parts of the world, in order to prevent faeces from contaminating the environment. However, having the facility does not in itself guarantee the isolation of faecal contamination. Even where pit latrines are in use, faecal contamination can get into drinking water and food and thereby into the mouth, or directly from fingers into the mouth. Various routes of transmission, such as fingers, flies, soil, and water, may require different barriers if the spread of contamination is to be cropped. This makes the prevention of diarrhoea and worm infections complex, as shown in Figure 1.
This diagram, often called the F diagram, clearly shows the different transmission routes whereby pathogens can get from the faeces of an infected person through fluids (mainly drinking water), fields (soil), fingers, and food. Some of the most effective primary and secondary (behavioural) barriers are indicated. You can see that there are at least nine barriers/facilities associated with hygiene practices. Clearly, numbers 1 and 2, pit latrines and Ventilated Improved Pit (VIP) latrines respectively, are very important physical barriers. If they are constructed and used properly, they can prevent faeces from contaminating water sources, soil, and food. The rest of the barriers relate to hygiene practices such as the protection of water sources (4) irrespective of the existence of latrines; hand-washing at critical times - after defecation, after cleaning children's bottoms, before handling food, and before eating and/or feeding (5); protection of food by safe storage (6); safe handling (7); protection of water in transit and in the home (8); and, washing raw foods before eating them (9).
Do improved hygiene practices really make a difference to health? Research shows that hygiene-related practices such as the safe disposal of faeces and hand-washing after contact with faecal material can reduce the rates of intestinal infection considerably. Consider the following figures:
· Hand-washing with soap and water can reduce diarrhoeal disease by 35% or more. Hand-washing can also help to reduce the prevalence of eye infections such as conjunctivitis and trachoma.
· Safe disposal of faeces serves as a primary barrier to prevent faeces from contaminating the environment. It is particularly important to isolate the faeces of people with diarrhoea, most of whom are usually young children. Pit latrines, when used by adults and for the disposal of young children's stools, can reduce diarrhoea by 36% or more.
· Protection of water from faecal contamination can also reduce diarrhoea, because some diarrhoeal infections are water-borne. Water quality in the home can be improved by using only a protected water source for drinking purposes; by keeping water storage vessels clean, covered, and out of the reach of young children and domestic animals; by boiling water where practical; or by putting water in clear plastic containers and exposing them to sunshine for several hours. In the special case of guinea worm, filtering with a cloth filter can provide complete protection. Improved water quality can be associated with up to a 20% reduction in diarrhoea. However, increased quantity of water used, which results from better access to water, can bring about still greater reductions.
However, much remains to be learned about the links between improved water supply and sanitation facilities, and well-designed and implemented health/hygiene promotion and health. What is clear is that good hygiene practices are necessary for maintaining good health.