This publication presents guidelines for the development of quantitative estimates of health impacts attributable to water, sanitation and hygiene related risks at country or local level. Most of the data available for the methods used cover developing countries. Eleven diseases or injuries are reviewed, including diarrhoea, malnutrition, intestinal nematode infections, schistosomiasis, trachoma, dengue, malaria, lymphatic filariasis, onchocerciasis, Japanese encephalitis and drowning. Methods for pooling of expert judgement and for systematic literature reviews are outlined. The fractions of disease attributable to water, sanitation and hygiene (WSH) obtained by the methods outlined in this guide should be combined with national disease statistics for those diseases. The quantification of health impacts and development of understanding of the potential benefits of interventions provide an opportunity to highlight the disease burden that could be prevented through actions in WSH. This can assist in directing interventions, and more generally motivate policy action to prevent the disease burden, disproportionately affecting children in the lower socioeconomic segments of the population.

This is a World Health Organization report, Environmental Burden of Disease Series, No. 15