Malignant Catarrhal Fever in Brazilian cattle presenting with neurological syndrome

Abstract Malignant Catarrhal Fever (MCF) was investigated in the central nervous system of cattle with neurological syndrome. Two-hundred-ninety samples were analyzed by histology, and molecular methods to detect ovine herpesvirus type 2 (OvHV-2) were optimized and validated. The qualitative polymerase chain reaction (qualitative PCR) analytical sensitivity was 101 DNA copies/µL and found 4.8% (14/290) positive for OvHV-2. The quantitative polymerase chain reaction (qPCR) analytical sensitivity was 100 DNA copy/µL and 5.9% (17/290) positivity, with 47.1% (8/17) of the positive samples presenting histological evidence of non-purulent meningo-encephalitis. The qualitative PCR products (422 bp of the ORF75 region) were sequenced and submitted to phylogenetic analysis. Identity matrices showed 100% similarity in OvHV-2 samples obtained in this study and those recovered from GenBank, corroborating other studies.