RESUMO

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

RESUMO

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.

Assuntos

RESUMO

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

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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.

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.

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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)

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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

RESUMO

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.

Assuntos

RESUMO

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

RESUMO

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.

Assuntos

RESUMO

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)

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