Social and environmental epidemiology of schistosomiasis in Ghana

Chemotherapy has provided a realistic approach for controlling schistosomiasis in resource-poor settings such as sub-Saharan Africa and control programmes have mainly adopted an age-targeted strategy of implementation. However, it is being increasingly argued that the setting-specific context in which the transmission of schistosome infections occurs may render this global approach of chemotherapy implementation inefficient. Evidence from different endemic settings points to the fact that the transmission dynamics of schistosome infections is not merely an interplay between humans and the parasites, but also a series complex interactions between environmental and social processes. Hence the degree of the spatial heterogeneity, that often characterises the transmission of infections, may differ for different endemic settings depending on the extent of the interaction between these processes. This thesis employs geostatistical methodology in assessing the collective effects of the social and environmental determinants of schistosome transmission within different endemic settings in Ghana. It also explores how these processes may influence the patterns of transmission at the local level and how these patterns could be utilised in improving the effectiveness of mass chemotherapy intervention programmes