SEROPREVALENCE OF Trypanosoma vivax, Anaplasma marginale, and Babesia bovis IN DAIRY CATTLE

Abstract

In order to determine the prevalence of IgG against Trypanosoma vivax, Anaplasma marginale, and Babesia bovis in dairy cattle in southern Minas Gerais, four hundred cows from 40 dairy farms  were randomly selected and distributed in 14 municipalities. Seroprevalence was determined by indirect immunofluorescence assay (IFA). Interviews were conducted to characterize producers and dairy production. Univariate analysis was carried out using chi-square (x2) or Fisher’s exact test. The multiple model was constructed with variables associated with p ? 0.25 by x2 test using generalized estimating equations (GEE). True prevalence at herd level was 49.6% (31.7–67.5), 100% (92.1–100), and 100% (86.5–100) for T. vivax, A. marginale, and B. bovis, respectively. At individual level, true seroprevalence was 9.9% (6.7–13.1), 96.2% (92.1–99.6), and 93.7% (89.4–97.2), respectively, for T. vivax, A. marginale, and B. bovis. Among the factors adjusted by logistic regression GEE  model, “total farm area” (p= 0.021, OR= 0.308, Ic95%= 0.114–0.836) and “fly season” (p= 0.016, OR= 2.133, Ic95%= 1.153–3.948) remained associated with seropositivity for T. vivax. As the State of Minas Gerais is considered non-endemic for T. vivax, producers and veterinarians should be informed about the risk of occurrence of bovine trypanosomiasis.

Keywords: anaplasmosis; babesiosis; dairy cattle; enzootic stability; trypanosomiasis.