An outbreak of malignant catarrhal fever in Sambar deer (Rusa unicolor) / Surto de febre catarral maligna em cervos Sambar (Rusa Unicolor)

Malignant catarrhal fever (MCF) is an infectious, pansystemic and highly fatal disease with wide geographic distribution. The species that are clinically prone to it include cattle, deer and bison. In Brazil, the disease in ruminants and deer is associated with the contact with sheep, especially during labor, when the fetal remains that are eliminated contain the ovine herpesvirus 2 (OvHV-2). The outbreak took place in a conservationist property in the city of Casimiro de Abreu/RJ, which hosted 23 Sambar deer, and, of these, 19 died, showing neurological signs. The deer lived in a location together with 15 male and female meat sheep. A female specimen of the Sambar deer (Rusa unicolor), aged approximately three years, which had presented with neurological clinical signs was referred to necropsy in the Setor de Anatomia Patológica at Universidade Federal Rural do Rio de Janeiro (SAP/UFRRJ). During necropsy, cerebrospinal fluid was sampled for analysis; fragments of several organs were fixated in 10% buffered formalin and processed for histopathological analysis. Fragments of occipital lobe, cerebellum and bulb were collected to perform the polymerase chain reaction (PCR). The diagnosis of this outbreak was based on epidemiological, clinical and pathological findings, and on the amplification of the OvHV-2 DNA through PCR. The histological changes were the base to confirm the MCF case and were characterized by degeneration of vascular endothelial cells, fibrinoid vasculitis, hyperplasia and necrosis of lymphoid organs. However, PCR was an important tool to confirm the diagnosis. MCF as an important disease with nervous symptomatology in deer.(AU)

A febre catarral maligna (FCM) é uma doença infecciosa, com distribuição geográfica ampla, pansistêmica e altamente fatal. As espécies clinicamente suscetíveis incluem bovino, cervo e bisão. No Brasil, a doença em ruminantes e cervídeos está associada ao contato com ovinos, principalmente durante o parto, no qual os envoltórios fetais eliminados contém, em suas secreções, o Herpesvírus ovino-2 (OvHV-2). O surto ocorreu em uma propriedade conservacionista no município de Casimiro de Abreu/RJ, que abrigava 23 cervos exóticos, onde foram registradas a morte de 19 destes, com sinais neurológicos. Os cervos habitavam em um piquete com 15 ovinos de corte, machos e fêmeas. Um exemplar de cervo sambar (Rusa unicolor), fêmea, com aproximadamente três anos de idade, que havia apresentado sinais clínicos neurológicos foi encaminhado para necropsia no Setor de Anatomia Patológica da Universidade Federal Rural do Rio de Janeiro (SAP/UFRRJ). Durante a necropsia foi realizada a coleta de líquido cefalorraquidiano e de fragmentos de lobo occipital, cerebelo e bulbo, para a realização de reação em cadeia da polimerase (PCR). Fragmentos de diversos órgãos foram fixados em formalina 10% tamponada e processados para a análise histopatológica. O diagnóstico do presente surto foi estabelecido com base nos achados epidemiológicos, clínicos, patológicos e na amplificação do DNA do OvHV-2 através da PCR. As alterações histológicas foram a base para confirmar o caso de FCM e caracterizaram-se por degeneração de células endoteliais vasculares, vasculite fibrinoide, hiperplasia dos órgãos linfoides. Contudo, a PCR foi uma ferramenta importante para a confirmação do diagnóstico. Ressalta-se a importância da FCM na lista dos diagnósticos diferenciais de doenças que cursam com sintomatologia nervosa em cervídeos.(AU)

An outbreak of malignant catarrhal fever in Sambar deer (Rusa unicolor) / Surto de febre catarral maligna em cervos Sambar (Rusa Unicolor)

Malignant catarrhal fever (MCF) is an infectious, pansystemic and highly fatal disease with wide geographic distribution. The species that are clinically prone to it include cattle, deer and bison. In Brazil, the disease in ruminants and deer is associated with the contact with sheep, especially during labor, when the fetal remains that are eliminated contain the ovine herpesvirus 2 (OvHV-2). The outbreak took place in a conservationist property in the city of Casimiro de Abreu/RJ, which hosted 23 Sambar deer, and, of these, 19 died, showing neurological signs. The deer lived in a location together with 15 male and female meat sheep. A female specimen of the Sambar deer (Rusa unicolor), aged approximately three years, which had presented with neurological clinical signs was referred to necropsy in the Setor de Anatomia Patológica at Universidade Federal Rural do Rio de Janeiro (SAP/UFRRJ). During necropsy, cerebrospinal fluid was sampled for analysis; fragments of several organs were fixated in 10% buffered formalin and processed for histopathological analysis. Fragments of occipital lobe, cerebellum and bulb were collected to perform the polymerase chain reaction (PCR). The diagnosis of this outbreak was based on epidemiological, clinical and pathological findings, and on the amplification of the OvHV-2 DNA through PCR. The histological changes were the base to confirm the MCF case and were characterized by degeneration of vascular endothelial cells, fibrinoid vasculitis, hyperplasia and necrosis of lymphoid organs. However, PCR was an important tool to confirm the diagnosis. MCF as an important disease with nervous symptomatology in deer.(AU)

A febre catarral maligna (FCM) é uma doença infecciosa, com distribuição geográfica ampla, pansistêmica e altamente fatal. As espécies clinicamente suscetíveis incluem bovino, cervo e bisão. No Brasil, a doença em ruminantes e cervídeos está associada ao contato com ovinos, principalmente durante o parto, no qual os envoltórios fetais eliminados contém, em suas secreções, o Herpesvírus ovino-2 (OvHV-2). O surto ocorreu em uma propriedade conservacionista no município de Casimiro de Abreu/RJ, que abrigava 23 cervos exóticos, onde foram registradas a morte de 19 destes, com sinais neurológicos. Os cervos habitavam em um piquete com 15 ovinos de corte, machos e fêmeas. Um exemplar de cervo sambar (Rusa unicolor), fêmea, com aproximadamente três anos de idade, que havia apresentado sinais clínicos neurológicos foi encaminhado para necropsia no Setor de Anatomia Patológica da Universidade Federal Rural do Rio de Janeiro (SAP/UFRRJ). Durante a necropsia foi realizada a coleta de líquido cefalorraquidiano e de fragmentos de lobo occipital, cerebelo e bulbo, para a realização de reação em cadeia da polimerase (PCR). Fragmentos de diversos órgãos foram fixados em formalina 10% tamponada e processados para a análise histopatológica. O diagnóstico do presente surto foi estabelecido com base nos achados epidemiológicos, clínicos, patológicos e na amplificação do DNA do OvHV-2 através da PCR. As alterações histológicas foram a base para confirmar o caso de FCM e caracterizaram-se por degeneração de células endoteliais vasculares, vasculite fibrinoide, hiperplasia dos órgãos linfoides. Contudo, a PCR foi uma ferramenta importante para a confirmação do diagnóstico. Ressalta-se a importância da FCM na lista dos diagnósticos diferenciais de doenças que cursam com sintomatologia nervosa em cervídeos.(AU)

Taxa de infecção pelo Herpesvírus ovino tipo 2 (OvHV-2)em rebanhos de ovinos no Distrito Federal

ABSTRACT: Malignant catarrhal fever (MCF) is a disease caused by bovine infection with ovine herpesvirus type 2 (OvHV-2) and responsible for economic losses in different Brazilian regions. This paper describes the molecular detection of OvHV-2 by nested-PCR (nPCR) in nasal secretion/exfoliation samples and blood cell fraction (BCF) of sheep from 8 properties in the Federal District. Among the 188 nasal samples, 88 (41.5%) were positive to OvHV-2. Pregnant ewe presented no differences at the infection rate in comparison with parous females. Newly calved sheep showed higher OvHV-2 infection rate than female over 60 days of calving. Nasal samples allowed the detection of infected animals by nPCR with efficiency about twice than that in the blood cell fraction samples. In Brazil, epidemiological information about OvHV-2 infection in sheep flocks and factors involved in emergence of FCM outbreaks in cattle are still scarce. This study may provide support for elucidating some characteristics of the disease and for further epidemiological studies in the Federal District and other Brazilian States.

RESUMO: A febre catarral maligna (FCM) é uma doença causada pela infecção de bovinos pelo herpesvírus ovino tipo 2 (OvHV-2), responsável por perdas econômicas em diferentes regiões do Brasil. Neste trabalho descreve-se a detecção molecular por nested-PCR (nPCR) do OvHV-2 em amostras de secreção/esfoliação nasal e fração celular sanguínea (FCS) de ovinos provenientes de 8 propriedades do Distrito Federal. Das 188 amostras nasais analisadas, 88 (41,5%) foram positivas. Ovelhas prenhes não apresentaram diferenças na taxa de infecção em comparação com fêmeas paridas. Fêmeas recém-paridas apresentaram taxa de infecção pelo OvHV-2 maior que em animais que pariram há mais de 60 dias. Amostras de secreção/esfoliação nasal permitiram a detecção por nPCR de animais infectados com uma eficiência aproximadamente duas vezes maior que em amostras de fração celular sanguínea. No Brasil, informações epidemiológicas sobre a infecção pelo OvHV-2 nos rebanhos ovinos e fatores envolvidos no surgimento de surtos de FCM em bovinos são escassos. Este estudo pode servir de subsídio para elucidar as características da enfermidade e para novos estudos sobre a epidemiologia da doença no Distrito Federal e em outros Estados do Brasil.

Malignant Catarrhal Fever in Brazilian cattle presenting with neurological syndrome

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.(AU)

Taxa de infecção pelo Herpesvírus ovino tipo 2 (OvHV-2) em rebanhos de ovinos no Distrito Federal / Ovine herpesvirus type 2 (OvHV-2) infection rate in sheep herds of the Federal District, Brazil

A febre catarral maligna (FCM) é uma doença causada pela infecção de bovinos pelo herpesvírus ovino tipo 2 (OvHV-2), responsável por perdas econômicas em diferentes regiões do Brasil. Neste trabalho descreve-se a detecção molecular por nested-PCR (nPCR) do OvHV-2 em amostras de secreção/esfoliação nasal e fração celular sanguínea (FCS) de ovinos provenientes de 8 propriedades do Distrito Federal. Das 188 amostras nasais analisadas, 88 (41,5%) foram positivas. Ovelhas prenhes não apresentaram diferenças na taxa de infecção em comparação com fêmeas paridas. Fêmeas recém-paridas apresentaram taxa de infecção pelo OvHV-2 maior que em animais que pariram há mais de 60 dias. Amostras de secreção/esfoliação nasal permitiram a detecção por nPCR de animais infectados com uma eficiência aproximadamente duas vezes maior que em amostras de fração celular sanguínea. No Brasil, informações epidemiológicas sobre a infecção pelo OvHV-2 nos rebanhos ovinos e fatores envolvidos no surgimento de surtos de FCM em bovinos são escassos. Este estudo pode servir de subsídio para elucidar as características da enfermidade e para novos estudos sobre a epidemiologia da doença no Distrito Federal e em outros Estados do Brasil.(AU)

Malignant catarrhal fever (MCF) is a disease caused by bovine infection with ovine herpesvirus type 2 (OvHV-2) and responsible for economic losses in different Brazilian regions. This paper describes the molecular detection of OvHV-2 by nested-PCR (nPCR) in nasal secretion/exfoliation samples and blood cell fraction (BCF) of sheep from 8 properties in the Federal District. Among the 188 nasal samples, 88 (41.5%) were positive to OvHV-2. Pregnant ewe presented no differences at the infection rate in comparison with parous females. Newly calved sheep showed higher OvHV-2 infection rate than female over 60 days of calving. Nasal samples allowed the detection of infected animals by nPCR with efficiency about twice than that in the blood cell fraction samples. In Brazil, epidemiological information about OvHV-2 infection in sheep flocks and factors involved in emergence of FCM outbreaks in cattle are still scarce. This study may provide support for elucidating some characteristics of the disease and for further epidemiological studies in the Federal District and other Brazilian States.(AU)

Taxa de infecção pelo Herpesvírus ovino tipo 2 (OvHV-2) em rebanhos de ovinos no Distrito Federal / Ovine herpesvirus type 2 (OvHV-2) infection rate in sheep herds of the Federal District, Brazil

A febre catarral maligna (FCM) é uma doença causada pela infecção de bovinos pelo herpesvírus ovino tipo 2 (OvHV-2), responsável por perdas econômicas em diferentes regiões do Brasil. Neste trabalho descreve-se a detecção molecular por nested-PCR (nPCR) do OvHV-2 em amostras de secreção/esfoliação nasal e fração celular sanguínea (FCS) de ovinos provenientes de 8 propriedades do Distrito Federal. Das 188 amostras nasais analisadas, 88 (41,5%) foram positivas. Ovelhas prenhes não apresentaram diferenças na taxa de infecção em comparação com fêmeas paridas. Fêmeas recém-paridas apresentaram taxa de infecção pelo OvHV-2 maior que em animais que pariram há mais de 60 dias. Amostras de secreção/esfoliação nasal permitiram a detecção por nPCR de animais infectados com uma eficiência aproximadamente duas vezes maior que em amostras de fração celular sanguínea. No Brasil, informações epidemiológicas sobre a infecção pelo OvHV-2 nos rebanhos ovinos e fatores envolvidos no surgimento de surtos de FCM em bovinos são escassos. Este estudo pode servir de subsídio para elucidar as características da enfermidade e para novos estudos sobre a epidemiologia da doença no Distrito Federal e em outros Estados do Brasil.(AU)

Malignant catarrhal fever (MCF) is a disease caused by bovine infection with ovine herpesvirus type 2 (OvHV-2) and responsible for economic losses in different Brazilian regions. This paper describes the molecular detection of OvHV-2 by nested-PCR (nPCR) in nasal secretion/exfoliation samples and blood cell fraction (BCF) of sheep from 8 properties in the Federal District. Among the 188 nasal samples, 88 (41.5%) were positive to OvHV-2. Pregnant ewe presented no differences at the infection rate in comparison with parous females. Newly calved sheep showed higher OvHV-2 infection rate than female over 60 days of calving. Nasal samples allowed the detection of infected animals by nPCR with efficiency about twice than that in the blood cell fraction samples. In Brazil, epidemiological information about OvHV-2 infection in sheep flocks and factors involved in emergence of FCM outbreaks in cattle are still scarce. This study may provide support for elucidating some characteristics of the disease and for further epidemiological studies in the Federal District and other Brazilian States.(AU)

Neurological diseases of cattle diagnosed by histopathology in Minas Gerais

This study was based on analysis of the central nervous system from cattle that died after developing neurological disease in the State of Minas Gerais from 2004 to 2010. Samples were analyzed by histopathology, histochemistry, and anti-Listeria monocytogenes immunohistochemistry. The frequency of positivity for the techniques used and distribution were determined, and the results were analyzed by Fisher"s exact test. Microscopic changes were observed in 29.5% (290/982) of bovine central nervous system samples examined. Inflammatory changes were the most frequent lesions (87.2% - 253/290) with 80% of cases (232/290) presenting non suppurative inflammation. Through histopathologic analyses, presumptive or conclusive etiology was obtained in 25.2% (73/290) of the samples. Etiologic diagnosis included inflammation by viruses (bovine herpesvirus infection in six samples; ovine herpesvirus-2 infection in eight samples); and bacteria (bacterial infection in 34 samples; and tuberculosis in six samples). Circulatory changes were evident in 26 cattle being nine cases of cerebral babesiosis. Degenerative lesions were detected in eight samples. One congenital change (cerebellar abiotrophy) and one neoplasm (astrocytoma) were identified. Neurological diseases other than rabies were diagnosed in Minas Gerais, and the use of histopathology allowed a more accurate differential diagnosis and a higher rate of conclusive diagnoses.

Neurological diseases of cattle diagnosed by histopathology in Minas Gerais

This study was based on analysis of the central nervous system from cattle that died after developing neurological disease in the State of Minas Gerais from 2004 to 2010. Samples were analyzed by histopathology, histochemistry, and anti-Listeria monocytogenes immunohistochemistry. The frequency of positivity for the techniques used and distribution were determined, and the results were analyzed by Fisher"s exact test. Microscopic changes were observed in 29.5% (290/982) of bovine central nervous system samples examined. Inflammatory changes were the most frequent lesions (87.2% - 253/290) with 80% of cases (232/290) presenting non suppurative inflammation. Through histopathologic analyses, presumptive or conclusive etiology was obtained in 25.2% (73/290) of the samples. Etiologic diagnosis included inflammation by viruses (bovine herpesvirus infection in six samples; ovine herpesvirus-2 infection in eight samples); and bacteria (bacterial infection in 34 samples; and tuberculosis in six samples). Circulatory changes were evident in 26 cattle being nine cases of cerebral babesiosis. Degenerative lesions were detected in eight samples. One congenital change (cerebellar abiotrophy) and one neoplasm (astrocytoma) were identified. Neurological diseases other than rabies were diagnosed in Minas Gerais, and the use of histopathology allowed a more accurate differential diagnosis and a higher rate of conclusive diagnoses.(AU)

Histophilus somni-induced thrombotic meningoencephalitis in cattle from northern Paraná, Brazil / Meningoencefalite trombótica-induzida por Histophilus somni em bovinos da região norte do Paraná

Thrombotic meningoencephalitis (TME) is a fatal neurological disease of cattle, predominantly from North America, that is caused by Histophilus somni with sporadic descriptions from other countries. This manuscript describes the occurrence of spontaneous TME in cattle from northern Paraná, Brazil. Most cattle had acute neurological manifestations characteristic of brain dysfunction. Hematological and cerebrospinal fluid analyses were not suggestive of bacterial infections of the brain. Histopathology revealed meningoencephalitis with vasculitis and thrombosis of small vessels that contained discrete neutrophilic and/or lymphocytic infiltrates admixed with fibrin at the brainstem, cerebral cortex, and trigeminal nerve ganglion of all animals. All tissues from the central nervous system used during this study were previously characterized as negative for rabies virus by the direct immunofluorescence assay. PCR and RT-PCR assays investigated the participation of infectious agents associated with bovine neurological disease by targeting specific genes of H. somni, Listeria monocytogenes, bovine herpesvirus -1 and -5, bovine viral diarrhea virus, and ovine herpesvirus-2. PCR and subsequent sequencing resulted in partial fragments of the 16S rRNA gene of H. somni from brain sections of all animals with histopathological diagnosis of TME; all other PCR/RT-PCR assays were negative. These findings confirmed the participation of H. somni in the neuropathological disease observed in these animals, extend the geographical distribution of this disease, and support previous findings of H. somni from Brazil.(AU)

Meningoencefalite trombótica (Thrombotic meningoencephalitis- TME) é uma doença neurológica fatal de bovinos ocasionada por Histophilus somni. A infecção tem sido descrita predominantemente na América do Norte e de forma esporádica em outros países. O objetivo deste estudo é relatar a ocorrência de TME em bovinos da região norte do estado do Paraná, Brasil. A maioria dos animais apresentaram sinais clínicos neurológicos característicos de disfunção cerebral aguda. Análises hematológicas e do fluido cerebrospinal não foram sugestivas de infecção bacteriana do cérebro. A histopatologia revelou meningoencefalite com vasculite e trombose de pequenos vasos com discreto infiltrado neutrofílico e/ou linfocítico mesclada com fibrina no tronco e córtex cerebral e no gânglio do nervo trigêmio de todos os animais. As amostras de sistema nervoso central incluídas nesse estudo foram previamente caracterizadas como negativas para raiva por meio de técnica de imunofluorescência direta. A participação de agentes infecciosos associados à doença neurológica em bovinos foi avaliada por técnicas moleculares como PCR e RT-PCR para amplificação parcial de genes de H. somni, Listeria monocytogenes, herpesvírus bovino 1 e 5, vírus da diarreia viral bovina e herpesvírus ovino 2. As seções do cérebro de todos os animais com diagnóstico histopatológico de TME foram positivas em PCR para a detecção do gene 16S rRNA de H. somni. O sequenciamento dos produtos amplificados confirmou a presença de DNA de H. somni nos fragmentos de cérebro avaliados. As reações de PCR/RT-PCR para todos os outros micro-organismos avaliados resultaram negativas. Os resultados desse estudo confirmaram a participação do H. somni nos episódios de doença neurológica observada nos animais avaliados, amplia a distribuição geográfica da TME e ratifica estudos prévios realizados no Brasil que demonstraram a presença de H. somni em outras formas de manifestação clínica das infecções por essa bactéria.(AU)

Histophilus somni-induced thrombotic meningoencephalitis in cattle from northern Paraná, Brazil / Meningoencefalite trombótica-induzida por Histophilus somni em bovinos da região norte do Paraná

Thrombotic meningoencephalitis (TME) is a fatal neurological disease of cattle, predominantly from North America, that is caused by Histophilus somni with sporadic descriptions from other countries. This manuscript describes the occurrence of spontaneous TME in cattle from northern Paraná, Brazil. Most cattle had acute neurological manifestations characteristic of brain dysfunction. Hematological and cerebrospinal fluid analyses were not suggestive of bacterial infections of the brain. Histopathology revealed meningoencephalitis with vasculitis and thrombosis of small vessels that contained discrete neutrophilic and/or lymphocytic infiltrates admixed with fibrin at the brainstem, cerebral cortex, and trigeminal nerve ganglion of all animals. All tissues from the central nervous system used during this study were previously characterized as negative for rabies virus by the direct immunofluorescence assay. PCR and RT-PCR assays investigated the participation of infectious agents associated with bovine neurological disease by targeting specific genes of H. somni, Listeria monocytogenes, bovine herpesvirus -1 and -5, bovine viral diarrhea virus, and ovine herpesvirus-2. PCR and subsequent sequencing resulted in partial fragments of the 16S rRNA gene of H. somni from brain sections of all animals with histopathological diagnosis of TME; all other PCR/RT-PCR assays were negative. These findings confirmed the participation of H. somni in the neuropathological disease observed in these animals, extend the geographical distribution of this disease, and support previous findings of H. somni from Brazil.(AU)

Meningoencefalite trombótica (Thrombotic meningoencephalitis- TME) é uma doença neurológica fatal de bovinos ocasionada por Histophilus somni. A infecção tem sido descrita predominantemente na América do Norte e de forma esporádica em outros países. O objetivo deste estudo é relatar a ocorrência de TME em bovinos da região norte do estado do Paraná, Brasil. A maioria dos animais apresentaram sinais clínicos neurológicos característicos de disfunção cerebral aguda. Análises hematológicas e do fluido cerebrospinal não foram sugestivas de infecção bacteriana do cérebro. A histopatologia revelou meningoencefalite com vasculite e trombose de pequenos vasos com discreto infiltrado neutrofílico e/ou linfocítico mesclada com fibrina no tronco e córtex cerebral e no gânglio do nervo trigêmio de todos os animais. As amostras de sistema nervoso central incluídas nesse estudo foram previamente caracterizadas como negativas para raiva por meio de técnica de imunofluorescência direta. A participação de agentes infecciosos associados à doença neurológica em bovinos foi avaliada por técnicas moleculares como PCR e RT-PCR para amplificação parcial de genes de H. somni, Listeria monocytogenes, herpesvírus bovino 1 e 5, vírus da diarreia viral bovina e herpesvírus ovino 2. As seções do cérebro de todos os animais com diagnóstico histopatológico de TME foram positivas em PCR para a detecção do gene 16S rRNA de H. somni. O sequenciamento dos produtos amplificados confirmou a presença de DNA de H. somni nos fragmentos de cérebro avaliados. As reações de PCR/RT-PCR para todos os outros micro-organismos avaliados resultaram negativas. Os resultados desse estudo confirmaram a participação do H. somni nos episódios de doença neurológica observada nos animais avaliados, amplia a distribuição geográfica da TME e ratifica estudos prévios realizados no Brasil que demonstraram a presença de H. somni em outras formas de manifestação clínica das infecções por essa bactéria.(AU)

Obliterative vasculitis caused by ovine herpesvirus type 2 in cattle / Obliterative vasculitis caused by ovine herpesvirus type 2 in cattle

Background: Malignant catarrhal fever (MCF) is a frequently fatal viral infection that affects various wild and domestic ruminants and even pigs, as recently reported. It is a disease characterized by lymphoproliferation, vasculitis and erosiveulcerative lesions in mucosa and skin. In Brazil, the virus that circulates and causes the disease has been identifi ed as OvHV-2. The aim of this study is to describe the clinicopathological changes in a cow with obliterative vasculitis caused by OvHV-2.Case: A two-year-old Gir cow with a history of intermittent diarrhea and progressive weight loss for approximately a year, which had not improved with antibiotic therapy, was euthanized and subjected to necropsy. In the necropsy, the liver was enlarged, fi rm, and had a marbled aspect all over the capsular and cut surfaces (light striations intercalated with dark areas). Cut surfaces also revealed thickening of the vessel walls, which exhibited a branched pattern. There was marked thickening of the small and large intestinal walls. The hepatic, mediastinal and mesenteric lymph nodes were enlarged. The samples were fi xed in 10% phosphate-buffered formalin, routinely processed for histology, embedded in paraffi n, cut 5-µm sections, and stained stained with hematoxylin and eosin. Additionally, sections of the liver and ileum were subjected to Massons trichrome staining. The main microscop

Background: Malignant catarrhal fever (MCF) is a frequently fatal viral infection that affects various wild and domestic ruminants and even pigs, as recently reported. It is a disease characterized by lymphoproliferation, vasculitis and erosiveulcerative lesions in mucosa and skin. In Brazil, the virus that circulates and causes the disease has been identifi ed as OvHV-2. The aim of this study is to describe the clinicopathological changes in a cow with obliterative vasculitis caused by OvHV-2.Case: A two-year-old Gir cow with a history of intermittent diarrhea and progressive weight loss for approximately a year, which had not improved with antibiotic therapy, was euthanized and subjected to necropsy. In the necropsy, the liver was enlarged, fi rm, and had a marbled aspect all over the capsular and cut surfaces (light striations intercalated with dark areas). Cut surfaces also revealed thickening of the vessel walls, which exhibited a branched pattern. There was marked thickening of the small and large intestinal walls. The hepatic, mediastinal and mesenteric lymph nodes were enlarged. The samples were fi xed in 10% phosphate-buffered formalin, routinely processed for histology, embedded in paraffi n, cut 5-µm sections, and stained stained with hematoxylin and eosin. Additionally, sections of the liver and ileum were subjected to Massons trichrome staining. The main microscop

Diagnóstico de febre catarral maligna em bovinos do Uruguai / Diagnosis of malignant catarrhal fever in cattle in Uruguay

Foi realizado um estudo retrospectivo de 14 focos de febre catarral maligna (FCM) em bovinos, detectados nos anos de 1999-2011, a partir dos arquivos da Seção Anatomia Patológica da Divisão de Laboratórios Veterinários (DILAVE) "Miguel C. Rubino" Montevideo. Foram analisados os dados epidemiológicos, apresentação clínica e lesões macroscópicas e histopatológicas. Para a detecção do herpesvírus ovino tipo 2 (OvHV-2) foi utilizada a técnica de PCR sobre as amostras do sistema nervoso central de bovinos de 12 focos. Os surtos ocorreram principalmente nos meses de primavera e verão, na região norte do país. Em 64% (9/14) dos focos ocorreram episódios individuais da enfermidade, enquanto que os casos coletivos foram 5, nos quais a morbidade e mortalidade oscilaram entre 2% e 5%, sendo a letalidade 100% em todos os relatos. Em 50% dos surtos foi confirmado o contato direto entre bovinos e ovinos, enquanto no restante não havia tal informação. Clinicamente predominaram os sinais de opacidade bilateral da córnea, conjuntivite, secreção nasal e ocular mucopurulenta, assim como a síndrome nervosa. Os achados de necropsia mais frequentes foram opacidade bilateral da córnea e lesões inflamatórias nas mucosas. Os achados histopatológicos caracterizaram-se por panvasculite necrótica sistêmica. Foi possível detectar o agente etiológico por PCR em 5 dos 12 casos analisados.(AU)

A retrospective study of 14 outbreaks of malignant catarrh fever (MCF) in cattle detected between 1999 and 2011 was performed based upon the files of the DILAVE "Miguel C. Rubino" Montevideo Pathology Laboratory. Epidemiological data, clinical presentation, gross and histopathological lesions were analyzed. PCR was used on central nervous system samples of 12 bovines for the detection of ovine herpesvirus type 2 (OvHV-2). The outbreaks occurred mainly in spring and summer in the northern region of the country. Sixty four percent (9/14) were individual episodes of the disease while five cases were collective, with morbidity and mortality rates were 2-5%, being the lethality 100% in all the reports. In 50% of the outbreaks the direct contact between cattle and sheep was confirmed, while there was not such information in the rest of the cases. Predominant clinical signs were bilateral corneal opacity, conjunctivitis, ocular and nasal mucopurulent discharge, and nervous syndrome. The most frequent necropsy findings were bilateral corneal opacity and inflammatory lesions in the mucosa. Histopathological findings were characterized by systemic necrotizing panvasculite. It was possible to detect the etiological agent by PCR in 5 out of 12 cases examined.(AU)

Obliterative vasculitis caused by ovine herpesvirus type 2 in cattle

Background: Malignant catarrhal fever (MCF) is a frequently fatal viral infection that affects various wild and domestic ruminants and even pigs, as recently reported. It is a disease characterized by lymphoproliferation, vasculitis and erosiveulcerative lesions in mucosa and skin. In Brazil, the virus that circulates and causes the disease has been identified as OvHV-2. The aim of this study is to describe the clinicopathological changes in a cow with obliterative vasculitis caused by OvHV-2. Case: A two-year-old Gir cow with a history of intermittent diarrhea and progressive weight loss for approximately a year, which had not improved with antibiotic therapy, was euthanized and subjected to necropsy. In the necropsy, the liver was enlarged, firm, and had a marbled aspect all over the capsular and cut surfaces (light striations intercalated with dark areas). Cut surfaces also revealed thickening of the vessel walls, which exhibited a branched pattern. There was marked thickening of the small and large intestinal walls. The hepatic, mediastinal and mesenteric lymph nodes were enlarged. The samples were fixed in 10% phosphate-buffered formalin, routinely processed for histology, embedded in paraffin, cut 5-µm sections, and stained with hematoxylin and eosin. Additionally, sections of the liver and ileum were subjected to Masson's trichrome staining. The main microscopic alterations were found in the vessels (arteries and veins) of the liver and intestine. Periportal fibrosis and marked pericholangitis which would sometimes form bridges were observed in the liver. Transmural and perivascular fibrosis; the muscular layer was ruptured and there was proliferation of the intima, which caused obliteration of the lumen were also present. The lymph nodes' medullae exhibited intense infiltration of macrophages and plasma cells with areas of fibrosis, capillary proliferation, and atrophy of medullary cords. Neovascularization and marked inflammatory infiltrates composed of lymphocytes, plasma cells, macrophages and eosinophils were also present. Masson's trichrome staining revealed areas of fibroplasia. The tissue samples of the carotid rete mirabile, brain and liver were submitted for identification of OvHV-2 by nested polymerase chain reaction (nPCR) tested was positive for ovine herpesvirus type 2. Discussion: The main histological findings (obliterative vasculitis observed in the small and large intestines, liver, and lymph nodes) plus the detection of viral DNA of OvHV-2 in fragments of the carotid rete mirabile, brain, and liver by nPCR confirmed the diagnosis of malignant catarrhal fever. Chronic cases of MCF in cattle are not often described. The disease is usually manifested in a hyperacute or acute form which culminates with death. The most frequent clinical presentation is the head and eye form, which is characterized by corneal opacity, and ocular, nasal, and oral serous discharge. Bovines with MCF usually exhibit macroscopic and microscopic changes in various organs due to the pansystemic characteristic of the virus, which causes vasculopathy and lymphadenopathy. In this report, the changes were restricted to the intestines, liver, and lymph nodes. The obliterative vasculitis seen in this case is similar to the changes described in cases of chronic. Other herpesviruses which cause lesions to the vascular wall can also cause hyperplasia of the muscular layer with progression to obliterative arteriopathy. This paper reports a presentation of MCR not previously described in Brazil. PCR was an important tool for the conclusion of this case.

Malignant catarrhal fever in cattle in the northern region of Mato Grosso - Brazil / Febre catarral maligna em bovinos no norte de Mato Grosso - Brasil

Background: Malignant catarrhal fever is an infectious pan-systemic viral disease, worldwide distribuition and highly fatal. The disease is described in many ruminant species, manly bovine. The lesions produced by malignant catarrhal fever in catlle affect upper respiratory and digestive tracts, lymph nodes, brain, eyes, kidney and urinary bladder. Affected animals present fever, depression, ocular and nasal discharge, erosions and ulcerations in the respiratory tract, keratoconjunctivitis, lymph node enlargement, hemorrhagic enteritis, encephalitis and arteritis. Four viruses are described as agents implicated on malignant catarrhal fever, although in Brazil, only ovine herpesvirus-2 has been described. Malignant catarrhal fever occurs in several regions of Brazil, including Mato Grosso state, where it was already reported in its southern region. The aim of this study was to describe the occurrence of malignant catarrhal fever in cattle in the northern region of the state of Mato Grosso.Case: Two affected bovine were necropsied. Tissue fragments were fixed with buffered formalin 10% and the hematoxylineosin sections were submitted to histopathology examination. Bovine DNA samples were extracted from paraffin embedded tissue fragments and submitted to nested PCR detection of ovine herpesvirus-2. The disease affected two bovine, one became clinically sick in October 2009 and the

Background: Malignant catarrhal fever is an infectious pan-systemic viral disease, worldwide distribuition and highly fatal. The disease is described in many ruminant species, manly bovine. The lesions produced by malignant catarrhal fever in catlle affect upper respiratory and digestive tracts, lymph nodes, brain, eyes, kidney and urinary bladder. Affected animals present fever, depression, ocular and nasal discharge, erosions and ulcerations in the respiratory tract, keratoconjunctivitis, lymph node enlargement, hemorrhagic enteritis, encephalitis and arteritis. Four viruses are described as agents implicated on malignant catarrhal fever, although in Brazil, only ovine herpesvirus-2 has been described. Malignant catarrhal fever occurs in several regions of Brazil, including Mato Grosso state, where it was already reported in its southern region. The aim of this study was to describe the occurrence of malignant catarrhal fever in cattle in the northern region of the state of Mato Grosso.Case: Two affected bovine were necropsied. Tissue fragments were fixed with buffered formalin 10% and the hematoxylineosin sections were submitted to histopathology examination. Bovine DNA samples were extracted from paraffin embedded tissue fragments and submitted to nested PCR detection of ovine herpesvirus-2. The disease affected two bovine, one became clinically sick in October 2009 and the

Febre catarral maligna em bovinos no norte de Mato Grosso - Brasil / Malignant catarrhal fever in cattle in the northern region of Mato Grosso - Brazil

Background: Malignant catarrhal fever is an infectious pan-systemic viral disease, worldwide distribuition and highly fatal. The disease is described in many ruminant species, manly bovine. The lesions produced by malignant catarrhal fever in catlle affect upper respiratory and digestive tracts, lymph nodes, brain, eyes, kidney and urinary bladder. Affected animals present fever, depression, ocular and nasal discharge, erosions and ulcerations in the respiratory tract, keratoconjunctivitis, lymph node enlargement, hemorrhagic enteritis, encephalitis and arteritis. Four viruses are described as agents implicated on malignant catarrhal fever, although in Brazil, only ovine herpesvirus-2 has been described. Malignant catarrhal fever occurs in several regions of Brazil, including Mato Grosso state, where it was already reported in its southern region. The aim of this study was to describe the occurrence of malignant catarrhal fever in cattle in the northern region of the state of Mato Grosso. Case: Two affected bovine were necropsied. Tissue fragments were fixed with buffered formalin 10% and the hematoxylineosin sections were submitted to histopathology examination. Bovine DNA samples were extracted from paraffin embedded tissue fragments and submitted to nested PCR detection of ovine herpesvirus-2. The disease affected two bovine, one became clinically sick in October 2009 and the other one in November 2010, in a dairy cattle farm where sheep and cows were raised together in the same feedlot. Disease occurrence was coincident with a four-month period after sheep's parturition. Clinical signs included apathy, decreased appetite, fever, nasal and vulvar discharge, recumbence, opisthotonos and death within four days. Necropsy revealed corneal opacity, multiple white foci in kidneys, crusts distributed over nasal and vulvar mucosa, catarrhal discharge and small erosions. Major histopathological findings had variable intensity and distribution and included perivascular inflammatory infiltrate, fibrinoid degeneration of arterial and arteriolar layers and epithelial necrosis with inflammatory infiltrate. Vascular histopathological findings included lymphocytic perivascular infiltrate with hyalinization, and a lymphoplasmocytic inflamatory infiltrated associated with histiocytes in the tunica media and vascular adventitia. Molecular examination detected ovine herpesvirus-2 DNA amplification. Discussion: In this study, malignant catarrhal fever diagnosis based on epidemiological, macroscopic, microscopic and molecular findings. Macroscopic and microscopic lesions observed are similar to those described in the literature. The disease occurs in a sporadic pattern, affecting few animals or as epizootic outbreaks affecting many bovines in a same herd. Four outbreaks were recorded in the southern region of Mato Grosso (Pantanal and Cerrado regions), three in a sporadic pattern and one as an epizootic outbreak. In the present study, the disease is reported in the northern region of the state (Amazonic region) as a sporadic form affecting two animals in the same farm. Histological examination is a valuable tool to diagnose malignant catarrhal fever; however rete miriabile should be carefully evaluated, once in this disease, vasculitis is a distinctive finding. PCR examination is an important tool to aid the diagnosis.

Molecular confirmation of ovine herpesvirus 2-induced malignant catarrhal fever lesions in cattle from Rio Grande do Norte, Brazil / Diagnóstico molecular de herpesvírus ovino tipo 2 em surto de febre catarral malígna em bovinos do Rio Grande do Norte

Molecular findings that confirmed the participation of ovine herpesvirus 2 (OVH-2) in the lesions that were consistent with those observed in malignant catarrhal fever of cattle are described. Three mixed-breed cattle from Rio Grande do Norte state demonstrated clinical manifestations that included mucopurulent nasal discharge, corneal opacity and motor incoordination. Routine necropsy examination demonstrated ulcerations and hemorrhage of the oral cavity, corneal opacity, and lymph node enlargement. Significant histopathological findings included widespread necrotizing vasculitis, non-suppurative meningoencephalitis, lymphocytic interstitial nephritis and hepatitis, and thrombosis. PCR assay performed on DNA extracted from kidney and mesenteric lymph node of one animal amplified a product of 423 base pairs corresponding to a target sequence within the ovine herpesvirus 2 (OVH-2) tegument protein gene. Direct sequencing of the PCR products, from extracted DNA of the kidney and mesenteric lymph node of one cow, amplified the partial nucleotide sequences (423 base pairs) of OVH-2 tegument protein gene. Blast analysis confirmed that these sequences have 98-100% identity with similar OVH-2 sequences deposited in GenBank. Phylogenetic analyses, based on the deduced amino acid sequences, demonstrated that the strain of OVH-2 circulating in ruminants from the Brazilian states of Rio Grande do Norte and Minas Gerais are similar to that identified in other geographical locations. These findings confirmed the active participation of OVH-2 in the classical manifestations of sheep associated malignant catarrhal fever.(AU)

Os achados moleculares confirmaram a participação do herpesvírus ovino tipo 2 (OVH-2) nas lesões observadas em um surto de febre catarral malígna em bovinos. Três bovinos oriundos de propriedade rural de Mossoró, Rio Grande do Norte apresentaram manifestações clínicas, que incluíram secreção nasal mucopurulenta, opacidade da córnea e incoordenação motora. A necropsia revelou ulcerações e hemorragias da cavidade oral, opacidade da córnea e linfonodomegalia. Os achados histopatológicos significativos incluíam vasculite necrosante generalizada, meningoencefalite não supurativa, nefrite intersticial linfocítica, hepatite linfocítica e trombose. A PCR, realizada a partir de DNA extraído do rim e do linfonodo mesentérico de um dos animais, amplificou um produto com 423 pares de base do gene da proteína do tegumento do herpesvírus ovino 2 (OVH-2). O sequenciamento direto dos produtos da PCR e a análise pelo Blast demonstraram que o produto amplificado apresentava 98-100% de identidade com sequências do OVH-2 depositadas no GenBank. As análises filogenéticas, baseadas nas sequências deduzidas de aminoácidos demonstraram que a cepa de OVH-2 circulando em ruminantes nos estados de Rio Grande do Norte e Minas Gerais são semelhantes àquelas identificadas em outras regiões geográficas. Esses achados confirmam a participação ativa de OVH-2 nas manifestações clássicas de febre catarral maligna em ovinos.(AU)

Neurological disorder in cattle associated with bovine herpesvirus 4 / Desordem neurológica em bovinos associada ao herpevírus bovino 4

A nested PCR assay was used to diagnose bovine encephalitis through herpesviruses including bovine herpesvirus 5 (BHV-5), bovine herpesvirus 1 (BHV-1), Aujeszky's disease virus (SHV-1), and ovine herpesvirus 2 (OHV-2) in 14 fragments of central nervous system (CNS) from cattle that died with neurological signs. In addition, as some samples of bovine herpesvirus type 4 (BHV-4) have been isolated from neural tissue, it was also tested by nested PCR. The cases of encephalitis occurred in isolation at different times of the year and did not present any seasonality. The duration of the clinical course ranged between 1 to 15 days, and in 64.3 percent of the cases it manifested between 1 to 2 days. The most frequently observed neurological signs were ataxia, recumbency, unsteadiness and inability to stand, opisthotonus, paddling movements, nystagmus and ptyalism. In the nested assay, there was no evidence of: BHV-1, SHV-1 or OHV-2 in the DNA obtained from the CNS in any of the samples. But the presence of BHV-4 was found in all fragments of the CNS in cattle which died presenting neurological signs. Moreover, BHV-5 was found in association with BHV-4 in two of these samples.(AU)

Nested PCR foi utilizada para o diagnóstico de encefalite bovina por herpesvírus incluindo o herpesvírus bovino 5 (BHV-5), o herpesvírus bovino 1 (BHV-1), o vírus da doença de Aujeszky (SHV-1) e o herpesvírus ovino 2 (OHV-2) em 14 fragmentos do sistema nervoso central (SNC) de bovinos que morreram com sinais neurológicos. Embora o BHV-4 não seja reconhecido como vírus neurotrófico, foi detectado nos casos de encefalite que ocorreram isoladamente em diferentes épocas do ano e não apresentaram nenhuma sazonalidade. A duração do curso clínico variou entre 1 e 15 dias, e em 64,3 por cento dos casos manifestou-se entre 1 e 2 dias. Os sinais neurológicos mais freqüentemente observados foram ataxia, apatia, instabilidade, opistótono, movimentos de pedalagem, nistagmo e sialorréia. Nos ensaios de PCR nested realizados a partir do DNA obtido do SNC, não foi encontrado evidência de: BHV-1, SHV-1 ou OHV-2 em nenhuma das amostras. Mas, a presença de BHV-4 foi encontrada em todos os fragmentos do SNC de bovinos que morreram com sinais neurológicos. Além disso, o BHV-5 foi encontrado em associação com o BHV-4 em duas dessas amostras.(AU)

Multiplex PCR for detection of Suid herpesvirus 1, Bovine herpesvirus 1, Bovine herpesvirus 5, Ovine herpesvirus 2 / PCR Multiplex para detecção dos principais herpesvírus neurológicos de ruminantes

Desenvolveu-se uma PCR multiplex (mPCR) para diagnóstico diferencial de encefalite bovina causada por herpesvírus suíno 1 (SuHV-1), herpesvírus bovino 1 (BoHV-1), herpesvírus bovino 5 (BoHV-5) e herpesvírus ovino 2 (OvHV-2). Os iniciadores foram projetados após alinhamento de sequências disponíveis no banco de genomas (GenBank) e a reação foi padronizada levando-se em consideração a concentração dos reagentes e os tipos diferentes de DNA polimerase. Após determinação da especificidade e sensibilidade, 65 amostras de encéfalo de bovinos com síndrome neurológica foram submetidas à análise. A sensibilidade analítica para detecção de BoHV-1, BoHV-5 e SuHV-1 foi, respectivamente, 10(1,2) TCID50/50µL, 10(1,0) TCID50/50µL, 10(1,3) TCID50/50µL na reação multiplex. Das 65 amostras analisadas, 10 foram positivas para BoHV-5, uma para BoHV-1 e cinco para OvHV-2. A mPCR descrita neste trabalho mostrou-se uma técnica útil para o diagnóstico diferencial de enfermidades relacionadas ao sistema nervoso central de bovinos.(AU)

The aim of this study was to develop a multiplex PCR (mPCR) for the differential diagnosis of bovine encephalitis caused by the suid herpesvirus 1 (SuHV-1), bovine herpesvirus 1 (BoHV-1), bovine herpesvirus 5 (BoHV-5) and ovine herpesvirus 2 (OvHV -2). The primers were designed after alignment of sequences available in GenBank and the reaction was developed by taking into account the concentration of reagents and different types of DNA polymerase. After determining the specificity and sensitivity to PCR, 65 brain samples from cattle with neurological syndrome were submitted to the reaction. The analytical sensitivity for detection of BoHV-1, BoHV-5 and SuHV-1 was, respectively, 10(1,2) TCID50/50µL, 10(1,0) TCID50/50µL, 10(1,3) TCID50/50µL. Ten samples were positive for BoHV-5, one for BoHV-1, one for SuHV-1 and five for OvHV-2. The mPCR described here is a useful technique for the differential diagnosis of diseases related to the central nervous system of cattle.(AU)

Malignant catarrhal fever-like lesions associated with ovine herpesvirus-2 infection in young calves (Bos indicus): a case report

Infection of susceptible ruminants, including domestic cattle (Bos taurus) and American bison (Bison bison), with ovine herpesvirus-2 (OvHV-2) may provoke the fatal vasculitis and lymphoproliferative syndrome, known as malignant catarrhal fever (MCF), reported worldwide. To the best of our knowledge, this is the first report of a clinical case of MCF-like lesions associated with ovine herpesvirus-2 (OvHV-2) infection in young calves (Bos indicus) including central nervous symptoms that occurred in Três Lagoas city, Mato Grosso do Sul state, a border town near São Paulo state, Brazil. The diagnosis was based on typical histological lesions characterized by systemic lymphohistiocytic and fibrinoid vasculitis, confirmed by polymerase chain reaction and subsequent phylogenetic analysis of detected OvHV-2 sequences. This finding indicates that MCF disease is spread among herds concentrated in border areas between Mato Grosso do Sul and São Paulo states.(AU)

FEBRE CATARRAL MALIGNA EM BOVINOS NOS ESTADOS DO PARÁ E MARANHÃO

Febre Catarral Maligna (FCM) é uma enfermidade infecciosa viral, aguda, pansistêmica, que acomete principalmente ruminantes domésticos e selvagens. A doença possui alta letalidade e no Brasil tem sido relacionada ao herpesvírus ovino2. A doença é relatada em várias regiões do Brasil, porém não há dados da mesma na região norte do país e no estado do Maranhão. O objetivo deste trabalho foi descrever os achados epidemiológicos, clínicos, patológicos e moleculares de surtos de FCM ocorridos em bovinos de quatro propriedades rurais no estado do Pará e duas no estado do Maranhão. Em cinco propriedades foi observada a criação consorciada entre bovinos e ovinos. A taxa de morbidade variou de 0,07% a 37,14% em todos os surtos, enquanto a taxa de letalidade foi de 100% na maioria destes. Em apenas um surto, a letalidade foi de 99,5%, devido a recuperação de um animal. Os principais sinais clínicos incluíram hipertermia, opacidade de córnea, ceratoconjuntivite, secreção ocular e nasal, sialorreia, anorexia, diarreia, erosões e ulcerações na mucosa oral e desordens neurológicas. As principais alterações observadas nas necropsias foram lesões erosivas e ulcerativas nas mucosas da cavidade oral, da língua, da gengiva, do esôfago, da cavidade nasal e da traqueia. Adicionalmente foi observado exsudato catarral nas narinas, hiperemia e edema nos cornetos nasais, além de petéquias e hematomas na face central da língua e esôfago, respectivamente. Outros achados relevantes nos surtos foram aumento de volume de linfonodos e placas de Peyer, focos esbranquiçados no córtex renal, lesões ulcerativas e hemorrágicas na bexiga e hiperemia nas leptomeninges do encéfalo. Microscopicamente, o principal achado foi vasculite com necrose fibrinoide em artérias de pequeno e médio calibre de múltiplos órgãos. Outros achados frequentes foram necrose e inflamação de epitélios de revestimento em vários tecidos, hiperplasia linfoide, bem como, encefalite, nefrite, cistite e pneumonia intersticiais não supurativas. O DNA do herpesvírus ovino tipo 2 foi detectado pela técnica de reação em cadeia de polimerase (PCR) em tecidos fixados em formol e incluídos em parafina de bovinos de um dos surtos no estado do Pará e nos dois surtos no estado do Maranhão. Os dados do presente trabalho confirmam a ocorrência da FCM em rebanhos bovinos do estado do Pará e Maranhão e demonstram que a enfermidade deve ser considerada no diagnóstico diferencial de doenças neurológicas ou digestivas em bovinos em ambos estados.

Malignant catarrhal fever (MCF) is an acute and systemic viral infectious disease of domestics and wild ruminants. The disease has high fatality rate and on Brazil has been associated to ovine herpesvirus-2. The disease is reported in several regions of Brazil, but there is no data the same in the north of the country and in the state of Maranhão. The aim this paper was reported the epidemiological, clinical, pathological and molecular findings of MCF outbreaks in cattle from four farms in the state of Pará and two in the state of Maranhão. In five farms was observed a mixed farming of cattle and sheep. The morbidity rate ranged from 0.07% to 37.14% in all outbreaks. While the fatality rate was 100% in almost outbreaks, but just one outbreak the fatality rate was 99.5% due to recovery of an animal. The main clinical signs included hyperthermia, corneal opacity, keratoconjunctivitis, ocular discharge and nose, drooling, anorexia, diarrhea, erosions and ulcerations in the oral mucosa and neurological disorders. The main changes observed in necropsies were erosive and ulcerative lesions in the mucosal of the oral cavity, tongue, esophagus, nasal cavity and trachea. Additionally it was observed catarrhal exudate in the nose, hyperemia and edema in the nasal turbinates, and petechiae and bruising in the central surface of the tongue and esophagus, respectively. Other relevant findings in the outbreaks were enlargement of lymph nodes and Peyer's patches, whitish foci in the renal córtex, ulcerative and hemorrhagic lesions in the bladder and hyperemia of leptomeninges of the brain. Microscopically, the main finding was vasculitis with fibrinoid necrosis in small and medium-sized arteries of multiple organs. Other common findings were necrosis and inflammation epithelium lining in several tissues, lymphoid hyperplasia, as well as nonsuppurative interstitial nephritis, cystitis and pneumonia. The ovine herpesvirus 2 DNA was detected by polymerase chain reaction (PCR) in tissues fixed in formalin and embedded in paraffin of cattle from a outbreak in the state of Pará and two outbreaks in the state of Maranhão. The present data confirm the occurrence of MCF in cattle herds on states of Pará and Maranhão and demonstrate that the disease must be considered in the differential diagnosis of neurological or digestive diseases in cattle in both states.