Spacial modeling of cutaneous leishmaniasis risk zones

Abstract

OBJECTIVE: To spatially delimit cutaneous leishmaniasis (CL) human contact risk zones (CoRZ) using remote sensing and geoprocessing techniques. METHODS: A total of 27 CL cases reported from 1992 to 1997 in the municipality Itapira, Brazil, were studied. The influence of some important environmental variables related to CL such as altitude and vegetation density measured by normalized difference vegetation index (NDVI) images were analyzed for each CoRZ. RESULTS: The results showed that about 50% of the dwellings where CL cases were reported were located less than 200 meters from the limits of forest remnant area; more than 70% of the total area of the CoRZ, for each criterion, were in altitudes lower than 750 meters; and about 50% of the CoRZ, for each criterion, were located in a very dense green area (NDVI ranging from 0.45 to 1.00). CONCLUSIONS: The study shows there may be three transmission modes in the study area: intra-forest, extra-forest (in this setting, transmission might be influenced by the vegetation density surrounding forest remnants); or domiciliary.