Retrospective study to identify infectious agents that cause encephalitis in cattle of Uruguay

Abstract

A retrospective study from 1999 to 2011 was performed to identify the main infectious agents that affect the central nervous system of cattle: rabies virus, Bovine Herpesvirus (BoHV), Listeria monocytogenes and virus of Malignant catarrhal fever (MCF). One hundred seventeen cases with bovine encephalitis were selected from the paraffin blocks files belonging to the Pathobiology Department of DILAVE «Miguel C. Rubino», Uruguay. Seventy three cases with histopathological lesions compatible with rabies, 20 with BoHV meningoencephalitis and 12 with lesions of listeriosis were analyzed by immunohistochemistry (IHC). PCR was used to study 12 cases with histopathological lesions consistent with MCF in the Laboratory of Molecular Biology of the Federal University of Mato Grosso, Brazil. Positive signal to the IHC were obtained in 89% cases classified as rabies, 30% of the cases with meningoencephalitis compatible with BoHV were positive for IHC detection of BoHV-1, and 20% to BoHV-5 and 92% of cases with listeriosis lesions showed positive signal for Listeria monocytogenes detection. Ovine herpesvirus type 2 was detected by PCR in 50% of cases classified as FCM. This study confirms the presence of these agents causing cattle encephalitis in Uruguay.