Neighbourhood Sanitation and Children's Diarrhea in Developing Countrie

Diarrhea is a leading cause of global child mortality. Sanitation has long been recognized as a key intervention against diarrhea, but it has been mostly evaluated as a household-level intervention for household-level health gain, without addressing its implications at neighbourhood-level. In this thesis, neighbourhood sanitation was defined as safe removal of excreta from the neighbourhood environment to prevent human contact. The effect and cost of neighbourhood sanitation intervention against children's diarrhea were evaluated. The distinct effects of neighbourhood sanitation conditions and household sanitation on diarrhea morbidity were distinguished and compared by a systematic literature review. The results suggested that sanitary neighbourhood conditions and household sanitation access are each associated with reduced diarrheal burden, at comparable magnitudes. The effect of neighbourhood sanitation was further investigated by an exposure-response analysis of neighbourhood-level coverage of sanitation facilities and under-five children's diarrheal illness. Health survey datasets from 29 developing countries were analysed using a multilevel regression model. The study found a non-linear exposure-response trend between neighbourhood sanitation coverage and diarrhea. A sanitation coverage threshold was identified, below which increase in sanitation coverage was associated with marginal reduction in diarrhea. The cost of neighbourhood sanitation delivered by centralized wastewater management (CWWM) and decentralized wastewater management (DWWM) strategies were compared in a case study site in India. As part of the analysis, the cost variability of DWWM was assessed for a broad range of system configurations. The study showed that NSan delivered by DWWM can be less costly than that by CWWM but with higher land requirement. The lower cost, together with the enhanced flexibility and resilience offered by DWWM, suggested that DWWM may be an adequate alternative to CWWM in rapidly developing regions. The findings of this thesis demonstrate that neighbourhood sanitation is an important and cost-effective intervention against children's diarrhea in developing countries.