Trypanosoma vivax em bovinos de Minas Gerais: achados epidemiológicos, morfológicos e moleculares

Abstract

Trypanosomiasis is a disease caused by a pathogenic protozoa of the genus Trypanosoma, and T. vivax is the most important etiologic agent for cattle. The aim of this work was to describe the expansion of T. vivax in different mesoregions of Minas Gerais State, the clinicopathological findings of trypanosomiasis in cattle and to evaluate the efficiency of the treatment used. The epizooty of trypanosomiasis in cattle occurred between 2015 and 2017 in the mesoregions of Campo das Verentes, Midwest and South and Southwest of Minas Gerais. As diagnostic forms, the visualization of trypomastigote forms in blood smears, PCR and DNA sequencing of some samples were used. The main clinical signs observed were apathy, drop in milk production, weight loss and reproductive failures. There were examined 11 herds and three cows were necropsied (Properties A, H and I). The most important macroscopic lesions were low corporal score, pale mucosa and spleen with white pulp hyperplasia. In five positive properties for T. vivax, tested after treatment with isometamidium hydrochloride, blood PCR was negative for the agent. The DNA sequencing showed 100% homology when compared to NCBI. These findings demonstrate the expansion of T. vivax in the state of Minas Gerais. The blood smears associated to PCR allows a better precision in the diagnosis. The isometamidium hydrochloride base has proved to be effective in treating the disease.