Análise espacial das áreas de favorabilidade para ocorrência de leishmaniose tegumentar americana no município de Seropédica - RJ

Abstract

This study aimed to evaluate the degree of favorability for the occurrence of american cutaneous leishmaniasis (ACL) in the municipality of Seropédica. The Geoenvironmental Analysis System Vista SAGA was used in the preparation of databases (thematic maps), environmental analysis and signatures. The spatial distribution of leishmaniasis was assessed based on the factors of land use and vegetation cover, soil type, elevation, slope and geomorphology. The factors used in the analysis were selected based on previous literature and the technical feasibility for the preparation of databases. Weights and grades were assigned to the factors and their categories, respectively, based on their importance to the life cycle of parasites of the genus Leishmania. The results of the environmental analysis were categorized to represent the spatial distribution of likelihoods, with risk areas classified as highly likely, very likely, likely, unlikely and highly unlikely with respect to the occurrence of ACL. For the municipality of Seropédica, 6.81% of its area was classified as highly likely, 65.14% as very likely, 17.98% as likely, 2.39% as unlikely and 0.07% as highly unlikely. Therefore, it can be classified overall as a very probable ACL-occurrence area. In addition, the highly likely and very likely risk areas have altimetric quotas ranging from 0-40 m, have slopes ranging from 0-2.5%, are situated upon planosol soil and have a geomorphology represented by colluvial-alluvial plains. Urban expansion exists in the highly likely risk areas, and pastures exist in the very likely risk areas. The areas having likely risks have altimetric quotas ranging from 40-80 m, have slopes ranging from 20-40% and are situated upon podzol1 soil, which is found in greater percentages on the dissected edges of structural plateaus with herbal vegetation and predominantly on rural sites with similar extensions of pasture areas. Unlikely risk areas exist mostly in altimetric quotas ranging from 80-120 m, have slopes ranging from 20-40%, are situated upon cambisol-2 soil and are located in the greatest percentages on the dissected edges of structural plateaus and rocks. Highly unlikely risk areas have altimetric quotas ranging from 120-160 m, have slopes of >40%, are situated upon cambisol-2 soil and are located in the greatest percentages on the dissected edges of structural plateaus and rocks. The evaluation process provided not only the ability to localize risk areas but also the ability to characterize the profiles of ecosystems with regards to the risk of ACL occurrence. The program Vista-SAGA proved to be a simple and efficient tool for the investigation of risk areas for ACL in Seropédica. In this way, the results can support decision making by the boards in charge of the control and prevention of ACL in Seropédica.