An outbreak of malignant catarrhal fever in Murrah buffaloes in Minas Gerais, Brazil

Abstract

Pesq. Vet. Bras. 29(5): 395-400, maio 2009 RESUMO.-[Surto de febre catarral maligna (FCM) em búfalos da raça Murrah no estado de Minas Gerais.] É relatado um surto de febre catarral maligna (FCM) em Minas Gerais, que resultou na morte de 5 búfalas e uma vaca de uma mesma propriedade. Quatro búfalas morreram com 10-15 dias após o início dos sinais clínicos e uma búfala foi sacrificada in extremis, após manifestar sinais clínicos semelhantes. O exame histopatológico revelou lesões comumente observadas em búfalos com FCM como epicardite e miocardite histiolinfocítica multifocal e pneumonia linfocítica intersticial. Além disso, vasculite linfocítica, principalmente na camada adventí-cia, com necrose fibrinóide da camada muscular, foi observada no rim, fígado, baço, linfonodos e cérebro. A seqüência de nucleotídeos amplificada pela técnica de PCR revelou 98% de homologia entre o fragmento de DNA amplificado da amostra do sistema nervoso central (SNC) da búfala com seqüências de OHV-2 previamente depositadas no Genbank. Adicionalmente, a técnica de PCR revelou a presença do DNA viral no sangue total de 2 búfalas, clinicamente sadias. O diagnóstico de FCM foi baseado em dados epidemiológicos, clínicos, patológicos, histopatológicos e semi-nested PCR. INTRODUCTIONMalignant catarrhal fever (MCF) is a pansystemic, often fatal, viral disease that occurs as a complex of syndromes 1

Molecular confirmation of ovine herpesvirus 2-induced malignant catarrhal fever lesions in cattle from Rio Grande do Norte, Brazil

“…The interstitial pneumonia observed in these cases have been previously described in MCF affecting a horse (Costa et al 2009a), cattle (Macêdo et al 2007), and buffalos (Costa et al 2009a) and might be due to vasculitis of the alveolar capillaries and arteries. The acute onset of the disease cumulating in death of all affected animals is a salient feature of MCF and has been descri- bed in outbreaks occurring in buffaloes (Costa et al 2009a) and cattle ) from different geographical regions of Brazil and also in cattle experimentally infected by OVH-2 (Garmatz et al 2004). During this outbreak, the affected animals in addition to horses and sheep were grazing within the same pastures; we believe that asymptomatic sheep would have been the most likely source of contamination.…”

“…Alternatively, the clinicopathological aspects of MCF are well described in most geographical regions of Brazil (Garmatz et al 2004, Lemos et al 2005, Macêdo et al 2007, Mendonça et al 2008, but most studies have not fully characterized OVH-2 by sequence analysis. Nevertheless, studies performed in different Brazilian geographical regions, that have used molecular techniques, have conϐirmed that FCM is associated with OVH-2 (Garmatz et al 2004, Mendonça et al 2008, Costa et al 2009a. This was further conϐirmed when experimentally induced manifestations of the disease were described in cattle (Garmatz et al 2004).…”

“…Moreover, molecular data obtained from genomic DNA extracted from the kidney and lymph node of cow #1 revealed the desired 423 bp amplicon of the OVH-2 tegument protein gene as previously described (Baxter et al 1993, Li et al 1995. Similar molecular approaches that have used the same primers but with nested--PCR also ampliϐied OVH-2 DNA from buffalos (Costa et al 2009a) and horses (Costa et al 2009b) from the state of Minas Gerais, and in an experimental cattle study done in Rio Grande do Sul (Garmatz et al 2004). Therefore, these ϐindings conϐirmed that the lesions were induced by OVH-2 and add to the few cases (Costa et al 2009a,b) that have fully characterized this disease by molecular techniques in Brazil.…”

“…However, characterization of MCF based on the sequencing of the OVH-2 tegument protein gene has been done in an outbreak occurring in buffaloes (Costa et al 2009a) and in a unique case in a foal (Costa et al 2009b) from Minas Gerais, using previously described speciϐic primers (Baxter et al 1993, Li et al 1995.…”

Two Different Macaviruses, ovine herpesvirus-2 and caprine herpesvirus-2, Behave Differently in Water Buffaloes than in Cattle or in Their Respective Reservoir Species

“…Indeed, MCF is of great concern among different species of buffaloes, particularly in Asia, but also in Brazil and Italy [29], [30], [42]; clinical MCF in free-ranging African buffaloes is considered an emerging disease [61]. In association with shared housing of water buffaloes and sheep and the frequency of MCF, OvHV-2 seems to be of high relevance [29]–[31].…”