Improving health is one of the main goals of water and environmental sanitation WES interventions. Despite this many aid and development workers may have only a limited knowledge of the infections they try to prevent. Although the relevant information does exist it is often scattered in specialised literature and rarely finds its way into the field. This manual addresses this problem by presenting information on these infections in relation to the interventions that fieldworkers typically control i.e water supply sanitation drainage solid waste management and vector control. It has been produced primarily for nonmedical aid and development workers but anyone working in WES or in the prevention of infections related to WES will find this book useful.