Padrões espaciais da raiva bovina e seus determinantes no estado de são paulo entre 1992 e 2003

Murilo Novaes Gomes

- Cattle rabies is a zoonosis that has been studied since the beginning of last century due to its importance in the public health, ecology and economy fields. The understanding of its epidemiology through an ecology approach is the starting point of this Thesis. This study understands that either territory or cattle raise of Sao Paulo State, Brazil, influence the natural history of rabies and leads to changes in the theoretical references so far used to establish surveillance and control areas. Considering this premise, two questions are developed in this Thesis How and where does the land use and cover, in set with the variables produced in a context of cattle ecosystem, interfere in the developing of cattle rabies epidemics in Sao Paulo State? And how can we develop models that contribute to the comprehension of these new patterns of the disease space-temporal distribution and its current determinants? In order to answer these two questions, we considered and elaborated two experiments. In the first one, the observed unit was Sao Paulo State and the spatial analysis unit was the municipality. Cattle rabies that occurred from 1992 to 2003 was descript and represented in space and time, what made possible to select a minor area to analyze its determinants. The select region was composed by an epidemic area added to some Minas Gerais municipalities located in the boundary, allowing the identification of associated factors to the epidemics and to its progression over the territory. In the second one, we evaluated the factors that were involved in the new patterns of rabies space-temporal distribution in the selected area. Spatial analysis unit was no more the municipality but a regular lattice composed by [3x3]Km2 and [6x6]km2 resolution cells, which were used to map the factors. We then studied the participation and weight of those factors by regression models. These models considered the hypothesis of spatial dependence among exploratory variables which allowed the establishment of spatial models for the multivariate regression analysis. From this moment, there were also established new possible determinants associated to the potential of cattle rabies cases in the area and time mentioned. From the experiments, we could observe that: the epidemics spread mainly over Vale do Paraíba and Vale do Ribeira, on the way to the boundary with Minas Gerais until the axle between the cities of Sao Paulo and Campinas; in the selected area, factors showed a strong spatial dependence so the methodological option of using spatial regression models was indeed effective; although originally treated as homogeneous, the selected area, in fact, showed strong spatial heterogeneity and was divided in four sub-regions, observing aspects of epidemics progression and its relation to the landscape features. The four sub-regions defined for the selection were: (A) Vale do Paraíba, (B) São José dos Campos, (C) boundary of Minas Gerais State until the conurbation São Paulo-Campinas and (D) boundary of Minas Gerais State until Sao Paulo peripheral depression. For each sub-region, results pointed out such conclusions: (1) the description of the epidemics that occurred through the Vale do Paraíba was done by the split of the valley of River Paraitinga and Paraíba do Sul. The strong presence of urban concentration and agriculture areas in the valley of the second river made them in two branches; (2) the presence of high lands next to those of low altitude added to Sao Jose dos Campos city urban area determined the conduction of the epidemics from the boundary of Minas Gerais State until the north coast of Sao Paulo State. (3) eventually, in the sub-regions (C) and (D), the epidemics followed its way mainly because of the declivity. Its strength gradually reduced from the boundary of Minas Gerais State until it reached huge areas of land use, such as sugar cane plantation, urban areas and forest areas. These new conditionings made intense pressure in the epidemics new patterns as well as in the features of its migration. They basically influenced the features of cattle raise. It happened because the areas of pasture, and consequently the cattle density, were more and more restricted to areas of high declivity. They also led to changes in the behavior of Desmodus rotundus such as their mobility and home range. We therefore emphasize that the comprehension of the changes and its causes in Sao Paulo State landscape and their strong relation with cattle activity is important to improve the effectiveness of surveillance actions towards cattle rabies epidemics control.

Padrões espaciais da raiva bovina e seus determinantes no estado de são paulo entre 1992 e 2003

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