Prevalence of antibodies to equine alphaviruses in the State of Pará, Brazil / Prevalência de anticorpos para alphavirus em equinos do estado do Pará, Brasil

The State of Pará comprises 26% of Brazilian Amazon region, where a large diversity of arboviruses has been described. This study sought to assess the prevalence and distribution of hemagglutination inhibition (HI) antibodies against antigens of four alphaviruses (Togaviridae: Alphavirus) from the species: Eastern equine encephalitis (EEEV), Western  equine encephalitis (WEEV), Mayaro virus (MAYV), and Mucambo virus (MUCV) in 753 serum samples of horses in Pará State, Brazil. All investigated arboviruses were detected and indicate that horses are susceptible to these alphaviruses, and show evidences of their active circulation in farm animals in the Brazilian Amazon.

O estado do Pará corresponde a 26% da Amazônia brasileira, onde uma grande diversidade de arbovírus foi descrita. Este estudo procurou avaliar a prevalência e a distribuição de anticorpos inibidores da hemaglutinação (IH) contra antígenos de quatro alfavirus (Togaviridae: Alphavirus), das espécies: Vírus da encefalite equina do leste (EEEV), Vírus da encefalite equina do oeste (WEEV), Vírus mayaro (MAYV) e Vírus mucambo (MUCV), de 753 amostras de soro de equinos no estado do Pará, Brasil. Todos os arbovirus pesquisados foram detectados, indicando que os equinos são suscetíveis a esses Alphavirus e mostrando evidências de sua circulação ativa em animais de fazenda na Amazônia brasileira.

Prevalence of antibodies to equine alphaviruses in the State of Pará, Brazil / Prevalência de anticorpos para alphavirus em equinos do estado do Pará, Brasil

The State of Pará comprises 26% of Brazilian Amazon region, where a large diversity of arboviruses has been described. This study sought to assess the prevalence and distribution of hemagglutination inhibition (HI) antibodies against antigens of four alphaviruses (Togaviridae: Alphavirus ) from the species: Eastern equine encephalitis (EEEV), Western equine encephalitis (WEEV), Mayaro virus (MAYV), and Mucambo virus (MUCV) in 753 serum samples of horses in Pará State, Brazil. All investigated arboviruses were detected and indicate that horses are susceptible to these alphaviruses, and show evidences of their active circulation in farm animals in the Brazilian Amazon.(AU)

O estado do Pará corresponde a 26% da Amazônia brasileira, onde uma grande diversidade de arbovírus foi descrita. Este estudo procurou avaliar a prevalência e a distribuição de anticorpos inibidores da hemaglutinação (IH) contra antígenos de quatro alfavirus (Togaviridae: Alphavirus ), das espécies: Vírus da encefalite equina do leste (EEEV), Vírus da encefalite equina do oeste (WEEV), Vírus mayaro (MAYV) e Vírus mucambo (MUCV), de 753 amostras de soro de equinos no estado do Pará, Brasil. Todos os arbovirus pesquisados foram detectados, indicando que os equinos são suscetíveis a esses Alphavirus e mostrando evidências de sua circulação ativa em animais de fazenda na Amazônia brasileira.(AU)

Prevalence of antibodies to equine alphaviruses in the State of Pará, Brazil / Prevalência de anticorpos para alphavirus em equinos do estado do Pará, Brasil

The State of Pará comprises 26% of Brazilian Amazon region, where a large diversity of arboviruses has been described. This study sought to assess the prevalence and distribution of hemagglutination inhibition (HI) antibodies against antigens of four alphaviruses (Togaviridae: Alphavirus) from the species: Eastern equine encephalitis (EEEV), Western  equine encephalitis (WEEV), Mayaro virus (MAYV), and Mucambo virus (MUCV) in 753 serum samples of horses in Pará State, Brazil. All investigated arboviruses were detected and indicate that horses are susceptible to these alphaviruses, and show evidences of their active circulation in farm animals in the Brazilian Amazon.(AU)

O estado do Pará corresponde a 26% da Amazônia brasileira, onde uma grande diversidade de arbovírus foi descrita. Este estudo procurou avaliar a prevalência e a distribuição de anticorpos inibidores da hemaglutinação (IH) contra antígenos de quatro alfavirus (Togaviridae: Alphavirus), das espécies: Vírus da encefalite equina do leste (EEEV), Vírus da encefalite equina do oeste (WEEV), Vírus mayaro (MAYV) e Vírus mucambo (MUCV), de 753 amostras de soro de equinos no estado do Pará, Brasil. Todos os arbovirus pesquisados foram detectados, indicando que os equinos são suscetíveis a esses Alphavirus e mostrando evidências de sua circulação ativa em animais de fazenda na Amazônia brasileira.(AU)

Eastern equine encephalitis on Federal District of Brazil and surrounding areas / Encefalomielite equina do leste no Distrito Federal e entorno

Background: Eastern equine encephalitis (EEE) is a highly lethal zoonotic disease caused by Eastern equine encephalitisvirus (EEEv), an RNA virus of the genus Alphavirus, family Togaviridae. The transmission of these alphaviruses is throughmosquitoes, mainly species of Culex, Aedes, Anopheles and Culiseta. Horses and humans are considered accidental hostsand the main reservoirs are birds and some wild rodents. The disease has been identified in Brazil by serological studies,but investigations with clinico-pathological descriptions are scarce. The present study aimed to describe the epidemiologyand clinical-pathological findings of four cases of EEE in horses from Midwestern Brazil.Materials, Methods & Results: Four confirmed cases of EEE in horses from the necropsy and histopathology files of theLaboratory of Veterinary Pathology (LPV) of the University of Brasília (UnB) were reviewed. Cases occurred betweenJanuary 2005 and April 2012. Samples of brain and spinal cord samples were fixed in formalin 10%, processed routinelyfor histopathology, and stained by hematoxylin and eosin (HE). Immuno-histochemistry (IHC) with the peroxidase streptoavidin-biotin method was done to confirm the diagnosis of EEEv infection in all cases. The slides were incubated withthe anti-EEEv monoclonal primary antibody (overnight, 1:100 dilution). The disease affected both young and adult horses.One case occurred in the summer and the other three in the fall. Clinical signs more frequently observed included circling,blindness, paresis, paralysis, somnolence, ataxia, head pressing, and recumbence...(AU)

Eastern equine encephalitis on Federal District of Brazil and surrounding areas / Encefalomielite equina do leste no Distrito Federal e entorno

Background: Eastern equine encephalitis (EEE) is a highly lethal zoonotic disease caused by Eastern equine encephalitisvirus (EEEv), an RNA virus of the genus Alphavirus, family Togaviridae. The transmission of these alphaviruses is throughmosquitoes, mainly species of Culex, Aedes, Anopheles and Culiseta. Horses and humans are considered accidental hostsand the main reservoirs are birds and some wild rodents. The disease has been identified in Brazil by serological studies,but investigations with clinico-pathological descriptions are scarce. The present study aimed to describe the epidemiologyand clinical-pathological findings of four cases of EEE in horses from Midwestern Brazil.Materials, Methods & Results: Four confirmed cases of EEE in horses from the necropsy and histopathology files of theLaboratory of Veterinary Pathology (LPV) of the University of Brasília (UnB) were reviewed. Cases occurred betweenJanuary 2005 and April 2012. Samples of brain and spinal cord samples were fixed in formalin 10%, processed routinelyfor histopathology, and stained by hematoxylin and eosin (HE). Immuno-histochemistry (IHC) with the peroxidase streptoavidin-biotin method was done to confirm the diagnosis of EEEv infection in all cases. The slides were incubated withthe anti-EEEv monoclonal primary antibody (overnight, 1:100 dilution). The disease affected both young and adult horses.One case occurred in the summer and the other three in the fall. Clinical signs more frequently observed included circling,blindness, paresis, paralysis, somnolence, ataxia, head pressing, and recumbence...

Surto de encefalomielite equina Leste na Ilha de Marajó, Pará / Eastern equine encephalitis on Marajó Island, Pará state, Brazil

Nove casos de encefalomielite equina foram estudados na Ilha de Marajó, estado do Pará, Brasil. Os equinos apresentavam dificuldade em se manter em estação, andavam em círculo, tinham acentuada depressão, pálpebras cerradas, paralisia da língua, tremores musculares, bruxismo, anorexia e desidratação. Alguns apresentavam diminuição dos reflexos auricular, palpebral, de ameaça, diminuição do tônus da língua e taquicardia. Posição de auto-auscultação foi observada com frequência. Os animais muitas vezes eram encontrados apoiados em troncos e cercas para se manterem em estação. À necropsia verificou-se hemorragia das leptomeninges e da medula, alguns apresentaram ainda aderência das leptomeninges. À histopatologia verificou-se encefalite difusa que afetava principalmente a substância cinzenta, com meningite e coroidite. Foi observada perivasculite mononuclear. Em dois equinos identificou-se o vírus da encefalomielite equina Leste pela reação de Semi-Nested transcrição reversa de polimerase em cadeia (Semi-Nested RT-PCR).(AU)

Nine cases of equine encephalomyelitis on Marajó Island, state of Pará, Brazil, were studied. The affected horses had difficulty to stand, walked in circles, with marked depression, closed eyelids, tongue paralysis, muscle tremors, bruxism, anorexia and dehydration. Some had their ear and eyelid reflexes diminished, decreased tongue tone and tachycardia; laid down frequently they kept their head on the chest. Often they were seen resting their head on tree trunks or fences. At necropsy, hemorrhages of the meninges and spinal cord, and in some animals also adhesion of the meninges were found. Histologically there was diffuse encephalitis affecting mainly the gray matter, with meningitis and choroiditis. Presence of perivascular cuffs consisting of mononuclear inflammatory cells was observed. From two horses the Eastern equine encephalitis virus was identified by semi-nested reverse transcription polymerase chain reaction (semi-nested RT-PCR).(AU)

Encefalomielite equina Leste na Ilha de Marajó, Pará

Nove casos de encefalomielite equina foram estudados na Ilha de Marajó, estado do Pará, Brasil. Os animais apresentavam dificuldade em se manter em estação, andar em círculo, acentuada depressão, pálpebras cerradas, paralisia da língua, tremores musculares, bruxismo, anorexia e desidratação. Alguns apresentavam diminuição dos reflexos auricular, palpebral, de ameaça, diminuição do tônus da língua e taquicardia. Posição de auto-auscultação foi observada com frequência. Os animais muitas vezes eram encontrados apoiados em troncos e cercas para se manterem em estação. À necropsia verificou-se hemorragia das leptomeninges e medula, alguns animais apresentaram ainda aderencia das leptomeninges. Na histopatologia verificou-se encefalite difusa afetando principalmente a substância cinzenta, com meningite e coroidite. Foi observada presença de manguitos perivasculares constituídos por células inflamatórias mononucleadas. Em dois animais identificou-se o Eastern equine encephalitis virus por semi nested transcrição reversa reação de polimerase em cadeia (Semi-Nested RT-PCR)

Nine cases of equine encephalomyelitis on Marajó Island, state of Pará, Brazil, were studied. The affected horses had difficulty to stand, walked in circles, with marked depression, closed eyelids, tongue paralysis, muscle tremors, bruxism, anorexia and dehydration. Some had their ear and eyelid reflexes diminished, decreased tongue tone and tachycardia; laid down frequently they kept their head on the chest. Often they were seen resting their head on tree trunks or fences. At necropsy, hemorrhages of the meninges and spinal cord, and in some animals also adhesion of the meninges were found. Histologically there was diffuse encephalitis affecting mainly the gray matter, with meningitis and choroiditis. Presence of perivascular cuffs consisting of mononuclear inflammatory cells was observed. From two horses the Eastern equine encephalitis virus was identified by semi-nested reverse transcription polymerase chain reaction (semi-nested RT-PCR).

Encefalomielite equina Leste na Ilha de Marajó, Pará

Nove casos de encefalomielite equina foram estudados na Ilha de Marajó, estado do Pará, Brasil. Os animais apresentavam dificuldade em se manter em estação, andar em círculo, acentuada depressão, pálpebras cerradas, paralisia da língua, tremores musculares, bruxismo, anorexia e desidratação. Alguns apresentavam diminuição dos reflexos auricular, palpebral, de ameaça, diminuição do tônus da língua e taquicardia. Posição de auto-auscultação foi observada com frequência. Os animais muitas vezes eram encontrados apoiados em troncos e cercas para se manterem em estação. À necropsia verificou-se hemorragia das leptomeninges e medula, alguns animais apresentaram ainda aderencia das leptomeninges. Na histopatologia verificou-se encefalite difusa afetando principalmente a substância cinzenta, com meningite e coroidite. Foi observada presença de manguitos perivasculares constituídos por células inflamatórias mononucleadas. Em dois animais identificou-se o Eastern equine encephalitis virus por semi nested transcrição reversa reação de polimerase em cadeia (Semi-Nested RT-PCR)

Nine cases of equine encephalomyelitis on Marajó Island, state of Pará, Brazil, were studied. The affected horses had difficulty to stand, walked in circles, with marked depression, closed eyelids, tongue paralysis, muscle tremors, bruxism, anorexia and dehydration. Some had their ear and eyelid reflexes diminished, decreased tongue tone and tachycardia; laid down frequently they kept their head on the chest. Often they were seen resting their head on tree trunks or fences. At necropsy, hemorrhages of the meninges and spinal cord, and in some animals also adhesion of the meninges were found. Histologically there was diffuse encephalitis affecting mainly the gray matter, with meningitis and choroiditis. Presence of perivascular cuffs consisting of mononuclear inflammatory cells was observed. From two horses the Eastern equine encephalitis virus was identified by semi-nested reverse transcription polymerase chain reaction (semi-nested RT-PCR).(AU)

Soroprevalência da encefalomielite eqüina do leste e do oeste no Município de Uruará, PA, Brasil / Seroprevalence of holders farms for eastern equine encephalitis and western equine encephalomyelitis in Uruará Municipality, Pará State, Northen Brazil

O objetivo do presente foi estimar a soroprevalência de anticorpos contra o vírus da EEE e da WEE utilizando como unidades de análise os eqüídeos e as propriedades rurais do tipo familiar do município de Uruará, PA. Os anticorpos contra o vírus das EEE e da WEE foram pesquisados pela microtécnica de soroneutralização. As seguintes prevalências de animais sororeatores para os diferentes vírus foram observadas: EEE 27,37% (IC 15,33 - 39,21%), WEE 1,05% (IC 0,06 - 6,78%). Para as propriedades obtivemos as seguintes prevalências: EEE 53,12% (IC 35,03 - 70,49%), WEE 3,12% (IC 0,16-18,00%).(AU)

The aim of this study was to verify the prevalence of herds with EEEV and WEEV infected animals, in Uruará municipal district, Pará State-Brazil. In view of that, the serum neutralization test was utilized. The following prevalence of positive herds were observed: 17 positive herds for EEEV out of 32 herds, therefore, prevalence is 53.12% (IC 35.03 - 70.49%). One positive herd was found for WEEV out of the 32 studied herds, thus performing 3.12% (IC 0.16 - 18.00%) prevalence. The prevalence of serum reactors animals were observed: 27,37% (IC 15,33 - 39,21 %), WEE 1,05% (IC 0,06 - 6,78%).(AU)

Seroprevalence of holders farms for eastern equine encephalitis and western equine encephalomyelitis in Uruará Municipality, Pará State, Northen Brazil / Soroprevalência da encefalomielite eqüina do leste e do oeste no Município de Uruará, PA, Brasil

The aim of this study was to verify the prevalence of herds with EEEV and WEEV infected animals, in Uruará municipal district, Pará State-Brazil. In view of that, the serum neutralization test was utilized. The following prevalence of positive herds were observed: 17 positive herds for EEEV out of 32 herds, therefore, prevalence is 53.12% (IC 35.03 - 70.49%). One positive herd was found for WEEV out of the 32 studied herds, thus performing 3.12% (IC 0.16 - 18.00%) prevalence. The prevalence of serum reactors animals were observed: 27,37% (IC 15,33 - 39,21%), WEE 1,05% (IC 0,06 - 6,78%).

O objetivo do presente foi estimar a soroprevalência de anticorpos contra o vírus da EEE e da WEE utilizando como unidades de análise os eqüídeos e as propriedades rurais do tipo familiar do município de Uruará, PA. Os anticorpos contra o vírus das EEE e da WEE foram pesquisados pela microtécnica de soroneutralização. As seguintes prevalências de animais sororeatores para os diferentes vírus foram observadas: EEE 27,37% (IC 15,33 - 39,21%), WEE 1,05% (IC 0,06 - 6,78%). Para as propriedades obtivemos as seguintes prevalências: EEE 53,12% (IC 35,03 - 70,49%), WEE 3,12% (IC 0,16 - 18,00%).