Comparação entre métodos de avaliação direta para o diagnóstico de babesiose em bovinos

Abstract

The objective of the present study was to compare three methods of direct observation: blood smear, ear tip smear and leucoplatelet cover, searching for the best method for the diagnosis of Babesia spp. in cattle. Seventy-seven bovines with suspected babesiosis were used. From these animals, blood was collected in jugular vein and ear tip. After obtaining the samples, the blood smears and the leucoplaquetary layer were made with material from the jugular and smear of the ear tip with material from the perforation of the ear tip. Of the 77 animals, 14,30% (n = 11) inclusions were found in at least one of the three evaluated methods. Of the positive animals, 36.35% (n = 4) were positive only in the blood smear and the ear tip smear alone was not able to diagnose the disease in any of the animals. The concordance coefficient obtained in the kappa test showed a poor reconciliation between the blood smear observation method, considered gold standard in the literature, with blood smear (k = 0.18) and with the leucoplatelet layer (k = -0, 12). The sensitivity and specificity of the blood smear was 40% and 100% and the leucoplatelet layer obtained 25% and 62%, respectively. The blood smear with blood obtained from the jugular was the method with the best results when compared to the other techniques for the diagnosis of babesiosis in cattle.