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RESEARCH PRODUCT

Paysage et risque sanitaire - Le cas de l'echinococcose alvéolaire. Approche multiscalaire

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description

Echinococcus multilocularis is a parasite of public health importance causing the fatal zoonotic disease alveolar echinococcosis. The parasite's eggs are dispersed in the environment through the fox faeces. Epidemiological issues associated with the disease led to the monitoring of the endemic status in foxes in France and in Europe. Fox faeces collected in the field were tested for the presence of the parasite and assembled in a georeferenced database. GIS-assisted analysis investigated relationships between landscape characteristics and potential risk. Three scale levels were successively explored. In the french Doubs département located in a high endemicity area, binary logistic regression has been used. Landscape indices associated with the presence of positive samples have been identified. The accuracy of the predictive models has been explored using the ROC curves methods. The mapping of landscape factors allowed for the delineation of areas potentially at risk for the parasite's presence. In France, fuzzy k-means have been used to assess optimal scale levels. A typology of landscapes surrounding collected samples has been conducted. The precise prevalence of each landscape type has then been computed. A global map has been established based on the expected susceptibility of the landscape to the parasite's life cycle. At the european scale, climatic data has been introduced and a potential southern limit of extension of the parasite has been determined. These results show the possibilities associated with spatial analysis and modelling tools in health risks issues.