A RETROSPECTIVE SEARCH FOR BOVINE HERPESVIRUS 5 (BOHV-5) IN THE BRAIN OF CATTLE AFFECTED BY NEUROLOGICAL DISEASE IN RIO DE JANEIRO STATE

Bovine herpesvirus 5 (BoHV-5) is an important agent of meningoencephalitis in cattle and has been identified in outbreaks of neurological disease in several Brazilian states. However, no report of BoHV-5-associated neurological disease in Rio Janeiro state (RJ) has been published to date. This article reports a retrospective investigation for BoHV-5 performed in 146 brain specimens of cattle affected by neurological disease, submitted to the virology laboratory of the Empresa de Pesquisa Agropecuaria do Estado do Rio de Janeiro (PESAGRO-RJ) between 1998 and 2001. Most specimens came from herds in the RJ state (130 or 89%) and a few from Minas Gerais counties (16 or 11%), close to the RJ border. All brain samples examined in this study were previously diagnosed negative for rabies virus. The specimens were submitted to PCR/nested-PCR for BoHV-5 sequences and virus isolation. From 146 analysed brains samples 48 (33%) were positive in at least one of the tests (PCR or virus isolation), 20 samples (14%) were positive in both assays, 19 samples (13%) were positive in Nested-PCR (n-PCR) and nine samples (6%) were characterized as BoHV-5 after virus isolation. The northeast region of the RJ contributed with most clinical specimens (92/146 or 63%) and presented the highest positivity (28/92 or 30%). These results demonstrated BoHV-5 association with neurological disease in bovine herds of RJ and MG and should therefore be included in differential diagnosis of neurological disease in cattle. The limitations of each of the diagnostic assays used here in led us to recommend the concomitant use of PCR and virus isolation to improve the sensitivity of the diagnosis of BoHV-5 infection. DOI:  http://dx.doi.org/10.17525/vrrjournal.v19i2.140