Meningoencefalite em bovinos causada por herpesvírus bovino-5 no Mato Grosso do Sul e São Paulo

Abstract

Fifteen outbreaks of bovine herpesvirus-type 5 (BHV-5) infection were diagnosed from August 1993 to December 1996. Fourteen outbreaks occurred in the State of Mato Grosso do Sul and one in the State of São Paulo. Cattle 6 to 60 months old were affected. Morbidity reached 0.05% to 5% and case fatality rate was nearly 100%. The disease occurred in different municipalities and at different times of the year. Clinical signs were exclusively nervous, and the clinical course varied from 1 to 15 days. The main histologic lesions were meningitis, diffuse encephalitis and necrosis of the cerebral cortex with intranuclear inclusion bodies in astrocytes and neurons. BHV-5 was isolated from 11 out of 12 brains of infected animals inoculated in calf testis cells and MDBK cells. The virus was identified by immunoperoxidase staining with use of monoclonal specific antibodies. Outbreaks of infection by BHV-5 represent 5% of the total number of bovine cases submitted for diagnosis to the Clinical Hospital of the University of Mato Grosso do Sul. These results indicate the importance of the disease in Mato Grosso do Sul and the need for its differentiation from other diseases which affect the nervous system. INDEX TERMS: Meningoencephalitis, bovine herpesvirus-5, BHV-5, cortical cerebral necrosis, cattle, Mato Grosso do Sul.1 Aceito para publicação em 6 de março de 1998. Os sinais clínicos foram exclusivamente nervosos e o curso da enfermidade variou de 1 a 15 dias. As principais lesões histológicas detectadas foram meningite e encefalite difusa com malacia do córtex cerebral e presença de corpúsculos de inclusão intranucleares em astrócitos e neurônios. O vírus foi isolado do cérebro de 11 de um total de 12 animais, e sua identidade confirmada por imunoperoxidase, utilizando-se anticorpos monoclonais específicos. Os surtos de encefalite por BHV-5 representam 5% dos diagnósticos realizados em bovinos pelo Hospital Veterinário da Universidade Federal do Mato Grosso do Sul. Os resultados deste trabalho evidenciam a importância da doença no Mato Grosso do Sul e indicam a necessidade de incluir a encefalite por BHV-5 no diagnóstico diferencial de outras doenças do sistema nervoso de bovinos frequentes no Estado. TERMOS DE INDEXAÇÃO: Meningoencefalite, herpesvírus bovino-5, BHV-5, polioencefalomalacia, bovinos, Mato Grosso do Sul.

Ruminant alphaherpesviruses related to bovine herpesvirus 1

“…In Australia and South America, this infection occurs in cattle not immunised against BoHV-1 and is inducing a major economic problem, mainly in central and southern Brazil and Argentina. Indeed, the morbidity rate may vary between 15 and 50% and the lethal rate is close to 100% [17,57,93,110,142]. In the USA, BoHV-5 has been associated with field cases of bovine encephalitis [31].…”

Bovine herpesvirus type 5 (BHV-5) in a calf with rabies

“…Thus, in most rabies laboratories, specimens with a negative diagnosis for rabies end up with no definitive diagnosis established. However, in recent years, studies in search for other possible pathogens in rabies-negative specimens have led to the detection BHV-5 in a considerable number of such samples (Salvador et al 1998, Pinto et al 2000. This virus has followed a rather different evolutionary pathway, where infections usually do not lead to the host's death, but rather establish a form of coexistence, with the establishment of latent infections (Turin et al 1999).…”

“…This is the first report of a mixed rabies/ BHV-5 infection in calves. (Riet-Correa et al 1989, Salvador et al 1998, Weiblen et al 1989). In addition, BHV-5 has become the most frequently detected agent in a study with brain specimens which resulted negative at rabies diagnosis (Pinto et al 2000).…”

Reativação e distribuição do DNA latente do herpesvírus bovino tipo 5 no encéfalo de ovinos infectados experimentalmente

“…Casos esporádicos ou pequenos surtos da infecção pelo BoHV-5 já foram relatados em vários países, mas a doença é particularmente frequente na Argentina e no Brasil, onde vários surtos tem sido relatados a cada ano (Carrillo et al 1983, Riet-Correa et al 1989, Weiblen et al 1989, Salvador et al 1998, Rissi et al 2007. Nestes países, a doença neurológica pelo BoHV-5 possui grande repercussão sanitária e econô-mica, muitas vezes confundindo-se com a raiva, a causa mais comum de encefalite em bovinos nas Américas (Barros et al 2006).…”