Evidence of the value attached by communities to cleanliness and, by implication, environmental sanitation is found in studies of diarrhoea. People's perceptions of its causes may be divided into three categories, physical, social and spiritual. In many cases, physical causes are identified and, although the germ theory is not explicitly stated, the faecal-oral transmission routes of diarrhoea appear to be understood. Households may associate diarrhoea with a polluted environment including uncovered food, dirty water and flies. Graphic descriptions of pollution have been quoted (de Zoysa et al., 1984):
- "We have to drink the dam water where animals and children bathe and the dirty water makes us ill."
- "Flies sit on dirt which they eat then they come on to uncovered foods and spit on to foods which we eat."
As on-site sanitation involves improving the physical environment, it may therefore be readily accepted as one means by which to reduce the incidence of disease.
Equally, social and spiritual causes are perceived to be important, and include, for example, female social indiscretions and witchcraft. But these three apparently unrelated causes of diarrhoea should not be interpreted as mutually exclusive or divergent approaches to disease. They are often closely interrelated in practice, within a holistic interpretation of the environment.
Efforts should be made to determine how a community's beliefs, knowledge, and control over the environment can be harnessed in a positive way. Careful judgement is required to distinguish between those beliefs and ritual behaviour that are conducive to good sanitation practice and those that need to be changed.