Seroprevalencia de tripanosomosis bovina determinada por elisai posterior al tratamiento profiláctico con isometamidium en un hato del municipio muñoz del estado apure, Venezuela

Bovine trypanosomosis generates annual economic losses in livestock production in the country. Some farms that have an extensive cattle production, have established a control annual plan of hemoparasites which involve the application of prophylactic trypanocidal drugs. In order to evaluate the variation of seroprevalence after an annual application of isomethamidium chloride hydrochloride 2%, a group of 513 heifers of Bos indicus Linnaeus, 1758 was sampled, in a herd of Muñoz County of Apure State, Venezuela. Four samples were carried out in an equally spaced over a period of nine month. A week before the first sampling was applied to each animal a dose of 1 mg/kg of the drug. Once at the laboratory, samples were analyzed by ELISA indirect testing using as antigen a purified extract of Trypanosoma evansi. The test was performed according to previously standardized protocol in the laboratory. The seroprevalence obtained for the different samples studied were expressed as percentages of positive animals: 75.60% (December 2009), 57.60% (March 2010), 41.60% (June 2010) and 53.40% (September 2010). The results showed a high seroprevalence when prophylactic treatment was applied, which was decreasing in the following months and then suffer an light increase, after six months of treatment application, however, no cases of clinical disease or the presence of the parasite by direct diagnostic tests were observed. It is recommended, to continue with regular assessment of animals and considered as a preventive health measure the rotation of the active compound employed.