Water Sanitation Health

Burden of disease and cost-effectiveness estimates

Poor water quality continues to pose a major threat to human health. Diarrhoeal disease alone amounts to an estimated 3.6 % of the total DALY global burden of disease and is responsible for the deaths of 1.5 million people every year (WHO 2012). It is estimated that 58% of that burden, or 842 000 deaths per year, is attributable tounsafe water supply, sanitation and hygiene and includes 361 000 deaths of children under age five, mostly in developing countries (WHO 2014).

A significant amount of disease could be prevented especially in developing countries through better access to safe water supply, adequate sanitation facilities and better hygiene practices. In order to allow informed decision-making on interventions aimed at disease prevention and control, it is crucial to carry out a sound economic evaluation of the various options available in specific settings.

WHO has undertaken a cost-effectiveness analysis - using the standard methodology developed by WHO - and a cost-benefit analysis at the global level. The costs, the health benefits and the additional benefits of a range of selected interventions to improve water and sanitation services were assessed for each of the 14 WHO sub-regions.

  • The costs of the interventions included the full investment and annual recurrent costs.
  • In the cost-effectiveness analysis, the health benefits were presented in DALYs averted.
  • In the cost-benefit analysis, total benefits of the interventions included time savings due to easier access, gain in productive time and treatment costs saved due to less illness, and the value of prevented deaths.

WHO is currently involved in the development of practical guidance to objectively assess at national level the burden of water-related diseases and the total costs and benefits of improving access to safe water supply and sanitation.