Can and should sanitation and hygiene programmes be expected to achieve health impacts?

Although the anticipated health benefits are not the only reason for undertaking sanitation and hygiene programmes, they do represent an important part of the justification. Studies and reviews over recent years have shown, however, that the health impacts of sanitation programmes can be quite small or even negligible. They have also provided no solid evidence that integrated (water, sanitation, hygiene) programming has any greater effect than addressing one or two of these components alone. Two questions arise: first, whether a certain level of sanitation usage and hygiene practice within a community is needed in order to achieve a measurable health impact (i.e. whether a minimum percentage of the population should be using safe sanitation); second, whether sanitation and hygiene interventions undertaken without accompanying water supply improvements are likely to have significant health benefits. In this opinion paper some plausible and practically relevant answers to these questions are extracted from the relevant literature. The conclusions are that a high level of sanitation usage (well over 65 per cent) and widespread handwashing practice are necessary to achieve significant health impact; and that in situations where water services are poor, sanitation and hygiene interventions, while valuable for other reasons, are unlikely to have significant health impacts. Sanitation and hygiene programmes may be justifiable even if they do not immediately achieve high levels of compliance and corresponding water supply improvements are not made; however, the justification should not be presented on the grounds of short-term health benefits.