RESUMO
A 17-y-old Rocky Mountain gelding was presented to the Virginia-Maryland Veterinary Teaching Hospital because of a 4-wk history of anorexia, weight loss, lethargy, and fever of unknown origin. Abdominal ultrasound revealed lymphadenomegaly of the abdominal and colonic lymph nodes, thickening of the wall of the large colon, and a mass associated with the large colon. The horse was euthanized given a poor prognosis. On autopsy, an ~20-cm diameter mass was found within the mesocolon between the right ventral and right dorsal colon. The mass had invaded through the colonic walls and formed a fistula between the 2 involved lumina. On histologic evaluation, the mass consisted of small numbers of large neoplastic lymphocytes, numerous small lymphocytes, and many foamy macrophages. A diagnosis of T-cell-rich, large B-cell lymphoma was made based on immunohistochemical staining for CD79a, CD3, and Iba1; concurrent infection with equid herpesvirus 5 was confirmed with in-situ hybridization (ISH). To our knowledge, neither a trans-colonic fistula resulting from alimentary lymphoma in a horse nor detection of intralesional equid herpesvirus 5 in equine alimentary lymphoma by ISH has been reported previously.
Assuntos
Herpesvirus Equídeo 1 , Doenças dos Cavalos , Linfoma Difuso de Grandes Células B , Cavalos , Animais , Masculino , Hospitais Veterinários , Hospitais de Ensino , Linfoma Difuso de Grandes Células B/veterinária , Colo/patologia , Linfócitos T , Doenças dos Cavalos/diagnósticoRESUMO
Equine herpesvirus type 1 (EHV-1) is an emerging pathogen that causes encephalomyelitis in horses and non-equid species. Several aspects of the immune response in the central nervous system (CNS), mainly regarding the role of inflammatory mediators during EHV-1 encephalitis, remain unknown. Moreover, understanding the mechanisms underlying extensive neuropathology induced by viruses would be helpful to establish therapeutic strategies. Therefore, we aimed to evaluate some aspects of the innate immune response during highly neurovirulent EHV-1 infection. C57BL/6 mice infected intranasally with A4/72 and A9/92 EHV-1 strains developed a fulminant neurological disease at 3 days post-inoculation with high viral titres in the brain. These mice developed severe encephalitis with infiltration of monocytes and CD8+ T cells to the brain. The inflammatory infiltrate followed the detection of the chemokines CCL2, CCL3, CCL4, CCL5, CXCL2, CXCL9 and CXCL-10 in the brain. Notably, the levels of CCL3, CCL4, CCL5 and CXCL9 were higher in A4/72-infected mice, which presented higher numbers of inflammatory cells within the CNS. Pro-inflammatory cytokines, such as interleukins (ILs) IL-1α, IL-1ß, IL-6, IL-12ß, and tumour necrosis factor (TNF), were also detected in the CNS, and Toll-like receptor (TLR) TLR2, TLR3 and TLR9 genes were also upregulated within the brain of EHV-1-infected mice. However, no expression of interferon-γ (IFN-γ) and IL-12α, which are important for controlling the replication of other herpesviruses, was detected in EHV-1-infected mice. The results show that the activated innate immune mechanisms could not prevent EHV-1 replication within the CNS, but most likely contributed to the extensive neuropathology. The mouse model of viral encephalitis proposed here will also be useful to study the mechanisms underlying extensive neuropathology.
Assuntos
Encéfalo/imunologia , Encefalite Viral/imunologia , Infecções por Herpesviridae/imunologia , Herpesvirus Equídeo 1/imunologia , Herpesvirus Equídeo 1/patogenicidade , Animais , Encéfalo/metabolismo , Encéfalo/virologia , Quimiocinas/genética , Quimiocinas/metabolismo , Citocinas/genética , Citocinas/metabolismo , Modelos Animais de Doenças , Encefalite Viral/virologia , Infecções por Herpesviridae/virologia , Imunidade Inata , Leucócitos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Receptores Toll-Like/genética , Regulação para Cima , Carga ViralRESUMO
Equine coital exanthema (ECE) is an infectious, venereally transmitted muco-cutaneous disease affecting mares and stallions, caused by equid alphaherpesvirus 3 (EHV3). Diagnostic tools for rapid identification of EHV3 are of primary importance to diminish the risk of EHV3 dissemination at the time of breeding. In the last years, it has been shown that the performance of the insulated-isothermal polymerase chain reaction (iiPCR) is comparable to virus isolation, nested PCR and real-time PCR (qPCR) in detecting pathogens of various animal species. Analytical sensitivity and specificity of the iiPCR were compared with a qPCR, using a plasmid containing the target region of the EHV3 glycoprotein G gene and an Argentinian EHV3 isolate (E/9283/07 C3A). In order to evaluate the diagnostic performance of the iiPCR, nucleic acids of 85 perineal and genital swabs (PGS) of mares and stallions were extracted by tacoTM mini and tested by both techniques. EHV3 was detected in 46 and 45 of the 85 PGS by the iiPCR and qPCR, respectively. There was almost perfect agreement between the two diagnostic methods (98.82%; 95% CI: 95.03-100%; κâ¯=â¯0.98). The iiPCR had a limit of detection of 95.00% at 6 genome equivalents per reaction and a detection endpoint for viral DNA comparable to that of the qPCR, and did not react with six non-targeted equine pathogens. The iiPCR represents a sensitive and specific method for the rapid on-site diagnosis of EHV3 infection. Its routinely implementation in breeding facilities, and artificial insemination and embryo transfer centers, will contribute to prevent the dissemination of this venereal, highly contagious disease in horses.
Assuntos
Genitália/virologia , Infecções por Herpesviridae/veterinária , Herpesvirus Equídeo 3/isolamento & purificação , Doenças dos Cavalos/diagnóstico , Técnicas de Diagnóstico Molecular/métodos , Períneo/virologia , Reação em Cadeia da Polimerase/métodos , Animais , Infecções por Herpesviridae/diagnóstico , Doenças dos Cavalos/virologia , Cavalos , Testes Imediatos , Sensibilidade e EspecificidadeRESUMO
Infection with equid alphaherpesvirus 1 (EHV-1) causes respiratory disease, abortion and neurological disorders in horses. Molecular epidemiology studies have demonstrated that a single nucleotide polymorphism (A2254/G2254) in the genome region of open reading frame 30 which results in an amino acid variation (N752/D752) of the EHV-1 DNA polymerase, is significantly associated with the neuropathogenic potential of naturally occurring strains. In recent years, an increase in the number of cases of equine neurological disease caused by neuropathogenic variants of EHV-1 has been observed in numerous countries. The purpose of this study was to detect the presence of the viral genome of EHV-1 and equid herpesvirus 4 (EHV-4) in the bronchopulmonary lymph nodes of 47 horses from various locations in Uruguay, obtained from a slaughterhouse, and to determine whether the EHV-1 genomes possessed the mutation associated with neuropathogenesis (G2254/D752). The genes encoding glycoprotein H (gH) of EHV-1 and glycoprotein B (gB) of EHV-4 were amplified by a semi-nested polymerase chain reaction. Of the samples analysed, 28% and 6% of lymph nodes contained the genes for gH and gB, respectively. The viral DNA polymerase gene was amplified and sequenced. Twelve of the 13 genomes sequenced presented the nucleotide G2254, while the remaining 1 showed both nucleotides, A2254 and G2254. The results confirm the presence of EHV-1 in Uruguay. Furthermore, there is evidence for the first time of the detection of EHV-4, and high-frequency detection of the neuropathogenic variant (G2254/D752) of EHV-1 in Uruguay. These findings provide new insights into the epidemiological situation of EHV-1 and EHV-4 in that country.
L'infection par l'herpèsvirus équin de type 1 (EHV-1, sous-famille des alpha- Herpesvirinae) provoque chez les chevaux des maladies respiratoires, des avortements et des troubles neurologiques. Des études d'épidémiologie moléculaire ont montré une corrélation significative entre la présence d'un polymorphisme nucléotidique simple (A2254 / G2254) dans la région génomique du cadre de lecture ouvert 30 (ORF30), se traduisant par une variation des acides aminés (N752 / D752) de l'ADN polymérase du virus EHV-1, et la neuropathogénicité potentielle des souches présentes sur le terrain. On constate depuis quelques années dans de nombreux pays une augmentation du nombre de chevaux atteints de troubles neurologiques dus aux variants neuropathogènes de l'EHV-1. Les auteurs présentent les résultats d'une étude visant à détecter la présence du génome viral de l'EHV-1 et de l'herpèsvirus équin de type 4 (EHV-4) dans des échantillons de ganglions lymphatiques broncho-pulmonaires de 47 chevaux provenant de diverses régions d'Uruguay, collectés à l'abattoir, et à déterminer si les génomes de l'EHV-1 présentaient la mutation associée avec cette neuropathogénicité (G2254 / D752). Dans un premier temps, une amplification en chaîne par polymérase semi-nichée a permis d'amplifier les gènes codant pour la glycoprotéine H (gH) de l'EHV-1 et la glycoprotéine B (gB) de l'EHV-4. Les gènes gH et gB étaient présents respectivement dans 28 % et 6 % des échantillons de ganglions lymphatiques analysés. Le gène de l'ADN polymérase virale a été amplifié puis séquencé. Au total, 12 des 13 génomes séquencés contenaient le nucléotide G2254 tandis que le treizième génome présentait à la fois les nucléotides A2254 et G2254. Ces résultats confirment la présence de l'EHV-1 en Uruguay. En outre, il s'agit du premier rapport faisant état de la présence de l'EHV-4 et de la fréquence de détection du variant neuropathogénique (G2254 / D752) de l'EHV-1 en Uruguay. Ces résultats apportent un nouvel éclairage sur la situation épidémiologique de l'EHV-1 et l'EHV-4 dans ce pays.
La infección por alfa-herpesvirus equino 1 (HVE1) causa en el caballo enfermedades respiratorias, abortos y trastornos neurológicos. Los estudios de epidemiología molecular han demostrado la existencia de una correlación significativa entre el potencial neuropatogénico de cepas presentes en la naturaleza y la presencia de un polimorfismo de nucleótido único (A2254/G2254) en la región genómica del marco abierto de lectura 30 (ORF30). Este polimorfismo se traduce en la variación de un aminoácido (N752/D752) en la ADN-polimerasa del HVE1. En los últimos años se ha observado en muchos países un aumento del número de casos de enfermedad neurológica equina causados por variantes neuropatógenas del HVE1. Los autores describen un estudio encaminado a detectar la presencia de genoma vírico del HVE1 y del herpesvirus equino 4 (HVE4) en ganglios linfáticos broncopulmonares de 47 caballos de varias localidades del Uruguay a partir de muestras obtenidas en mataderos, y a dilucidar después si el genoma de esos HVE1 poseía la mutación ligada a la neuropatogénesis (G2254/D752). En primer lugar se empleó una técnica de reacción en cadena de la polimerasa (PCR) semianidada para amplificar los genes que codifican la glucoproteína H (gH) del HVE1 y la glucoproteína B (gB) del HVE4. De las muestras de ganglios linfáticos analizadas, los genes de la gH y de la gB estaban presentes, respectivamente, en un 28% y un 6%. Se amplificó y secuenció el gen de la ADN-polimerasa vírica. Doce de los trece genomas secuenciados presentaban el nucleótido G2254, mientras que el restante contenía ambos nucleótidos, A2254 y G2254. Los resultados confirman la presencia del HVE1 en el Uruguay. Además, por primera vez, quedó demostrada la presencia del HVE4, así como la elevada frecuencia de la variante neuropatógena (G2254/D752) del HVE1, en el Uruguay. Estos resultados arrojan nueva luz sobre la epidemiología de los virus HVE1 y HVE4 en el país.
Assuntos
Genótipo , Infecções por Herpesviridae/veterinária , Herpesvirus Equídeo 1/genética , Herpesvirus Equídeo 1/isolamento & purificação , Doenças dos Cavalos/virologia , Animais , Anticorpos Antivirais/sangue , Variação Genética , Genoma Viral , Infecções por Herpesviridae/epidemiologia , Infecções por Herpesviridae/virologia , Doenças dos Cavalos/epidemiologia , Cavalos , Uruguai/epidemiologiaRESUMO
Partial nucleotide sequences of ORF72 (glycoprotein D, gD), ORF64 (infected cell protein 4, ICP4) and ORF30 (DNA polymerase) genes were compared with corresponding sequences of EHV-1 reference strains to characterize the molecular variability of Brazilian strains. Virus isolation assays were applied to 74 samples including visceral tissue, total blood, cerebrospinal fluid (CSF) and nasal swabs of specimens from a total of 64 animals. Only one CSF sample (Iso07/05 strain) was positive by virus isolation in cell culture. EHV-1 Iso07/05 neurologic strain and two abortion visceral tissues samples (Iso11/06 and Iso33/06) were PCR-positive for ORF33 (glycoprotein B, gB) gene of EHV-1. A sequence analysis of the ORF72, ORF64 and ORF30 genes from three EHV-1 archival strains (A3/97, A4/72, A9/92) and three clinical samples (Iso07/05, Iso11/06 and Iso33/06) suggested that among Brazilian EHV-1 strains, the amplified region of the gD gene sequence is highly conserved. Additionally, the analysis of ICP4 gene showed high nucleotide and amino acid identities when compared with genotype P strains, suggesting that the EHV-1 Brazilian strains belonged to the same group. All the EHV-1 Brazilian strains were classified as non-neuropathogenic variants (N752) based on the ORF30 analysis. These findings indicate a high conservation of the gD-, ICP4- and ORF30-encoding sequences. Different pathotypes of the EHV-1 strain might share identical genes with no specific markers, and tissue tropism is not completely dependent on the gD envelope, immediate-early ICP4 and DNA polymerase proteins.
Assuntos
Variação Genética , Infecções por Herpesviridae/veterinária , Herpesvirus Equídeo 1/classificação , Herpesvirus Equídeo 1/genética , Doenças dos Cavalos/virologia , Animais , Brasil , Análise por Conglomerados , Sequência Conservada , DNA Viral/química , DNA Viral/genética , Genótipo , Infecções por Herpesviridae/virologia , Cavalos , Dados de Sequência Molecular , Fases de Leitura Aberta , Filogenia , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Homologia de Sequência do Ácido NucleicoRESUMO
Partial nucleotide sequences of ORF72 (glycoprotein D, gD), ORF64 (infected cell protein 4, ICP4) and ORF30 (DNA polymerase) genes were compared with corresponding sequences of EHV-1 reference strains to characterize the molecular variability of Brazilian strains. Virus isolation assays were applied to 74 samples including visceral tissue, total blood, cerebrospinal fluid (CSF) and nasal swabs of specimens from a total of 64 animals. Only one CSF sample (Iso07/05 strain) was positive by virus isolation in cell culture. EHV-1 Iso07/05 neurologic strain and two abortion visceral tissues samples (Iso11/06 and Iso33/06) were PCR-positive for ORF33 (glycoprotein B, gB) gene of EHV-1. A sequence analysis of the ORF72, ORF64 and ORF30 genes from three EHV-1 archival strains (A3/97, A4/72, A9/92) and three clinical samples (Iso07/05, Iso11/06 and Iso33/06) suggested that among Brazilian EHV-1 strains, the amplified region of the gD gene sequence is highly conserved. Additionally, the analysis of ICP4 gene showed high nucleotide and amino acid identities when compared with genotype P strains, suggesting that the EHV-1 Brazilian strains belonged to the same group. All the EHV-1 Brazilian strains were classified as non-neuropathogenic variants (N752) based on the ORF30 analysis. These findings indicate a high conservation of the gD-, ICP4- and ORF30-encoding sequences. Different pathotypes of the EHV-1 strain might share identical genes with no specific markers, and tissue tropism is not completely dependent on the gD envelope, immediate-early ICP4 and DNA polymerase proteins.(AU)
Assuntos
Animais , Variação Genética , Infecções por Herpesviridae/veterinária , Herpesvirus Equídeo 1/classificação , Herpesvirus Equídeo 1/genética , Doenças dos Cavalos/virologia , Brasil , Análise por Conglomerados , Sequência Conservada , DNA Viral/química , DNA Viral/genética , Genótipo , Infecções por Herpesviridae/virologia , Cavalos , Dados de Sequência Molecular , Fases de Leitura Aberta , Filogenia , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Homologia de Sequência do Ácido NucleicoRESUMO
Partial nucleotide sequences of ORF72 (glycoprotein D, gD), ORF64 (infected cell protein 4, ICP4) and ORF30 (DNA polymerase) genes were compared with corresponding sequences of EHV-1 reference strains to characterize the molecular variability of Brazilian strains. Virus isolation assays were applied to 74 samples including visceral tissue, total blood, cerebrospinal fluid (CSF) and nasal swabs of specimens from a total of 64 animals. Only one CSF sample (Iso07/05 strain) was positive by virus isolation in cell culture. EHV-1 Iso07/05 neurologic strain and two abortion visceral tissues samples (Iso11/06 and Iso33/06) were PCR-positive for ORF33 (glycoprotein B, gB) gene of EHV-1. A sequence analysis of the ORF72, ORF64 and ORF30 genes from three EHV-1 archival strains (A3/97, A4/72, A9/92) and three clinical samples (Iso07/05, Iso11/06 and Iso33/06) suggested that among Brazilian EHV-1 strains, the amplified region of the gD gene sequence is highly conserved. Additionally, the analysis of ICP4 gene showed high nucleotide and amino acid identities when compared with genotype P strains, suggesting that the EHV-1 Brazilian strains belonged to the same group. All the EHV-1 Brazilian strains were classified as non-neuropathogenic variants (N752) based on the ORF30 analysis. These findings indicate a high conservation of the gD-, ICP4- and ORF30-encoding sequences. Different pathotypes of the EHV-1 strain might share identical genes with no specific markers, and tissue tropism is not completely dependent on the gD envelope, immediate-early ICP4 and DNA polymerase proteins.
Assuntos
Animais , Variação Genética , Infecções por Herpesviridae/veterinária , Herpesvirus Equídeo 1/classificação , Herpesvirus Equídeo 1/genética , Doenças dos Cavalos/virologia , Brasil , Análise por Conglomerados , Sequência Conservada , DNA Viral/química , DNA Viral/genética , Genótipo , Cavalos , Infecções por Herpesviridae/virologia , Dados de Sequência Molecular , Fases de Leitura Aberta , Filogenia , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Homologia de Sequência do Ácido NucleicoRESUMO
Mice are commonly used as an experimental model to investigate the Equid herpesvirus 1 (EHV-1) infection. This model easily reproduces the disease, and the clinical signs are more or less similar to those observed in the horse, the natural host. During natural infection, the acute course of respiratory infection is mandatory for the development of adaptive immune response. Since interactions between EHV-1 and anesthetics are possible, the study investigated whether the early events of murine pulmonary immune response could be affected by different anesthetics. Therefore, mice were experimentally infected with a unique EHV-1 strain under the effects of ether, ketamine/xylazine, or isoflurane. Clinical signs and histopathological lesions in the lungs were described, and the cell death and proliferation rates of sham-inoculated or infected animals were quantified using immunohistochemistry. Clinical signs were more severe in animals anesthetized with ether. Qualitative differences in the recruited inflammatory cells were observed following application of anesthesia. The level of infection between the infected groups was not statistically significant. However, lungs from ketamine/xylazine-anesthetized animals showed the highest cell death rates, whereas those from isoflurane-anesthetized animals showed the highest proliferation rates. It has been emphasized that anesthetics alone or their interactions with EHV-1 modify the response against the infection. An appropriate selection of the anesthetic during experimental studies is relevant to minimize wrong conclusions.
Assuntos
Anestésicos/farmacologia , Modelos Animais de Doenças , Infecções por Herpesviridae/imunologia , Infecções por Herpesviridae/patologia , Herpesvirus Equídeo 1 , Pulmão/patologia , Análise de Variância , Animais , Morte Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Imuno-Histoquímica , Isoflurano , Ketamina , Pulmão/efeitos dos fármacos , Camundongos , XilazinaRESUMO
Equid herpesvirus 1 (EHV-1) infection has a signifcant economic impact on equine production, causing abortion, respiratory disease, neonatal death and neurological disorders. The identifcation of specifc EHV-1 genes related to virulence and pathogenicity has been the aim of several research groups. The purpose of the present study was to analyze different genomic regions of Argentinean EHV-1 strains and to determine their possible relationship with virulence or clinical signs. Twenty-fve EHV-1 Argentinean isolates recovered from different clinical cases between 1979 and 2007 and two reference strains were amplifed and sequenced. The sequence alignments were carried out using Clustal X version 1.92 and the putative amino acid sequences were deduced using Bio-Edit version 7.05. Minor changes were observed. No changes that could be involved in the different virulence in the mouse model of three EHV-1 Argentinean strains were found. No genetic variants were observed. The genomic regions analyzed are unsuitable for differentiation between abortigenic strains and those isolated from neonatal deaths.
La infección por Herpesvirus equino 1 (EHV-1) tiene un signifcativo impacto económico en la producción equina mundial al causar abortos, enfermedad respiratoria, muertes perinatales y desórdenes neurológicos. La identifcación de genes específcos relacionados con la virulencia y patogenicidad de este virus ha sido el propósito de varios grupos de investigación. En este trabajo se analizaron diferentes regiones genómicas de cepas argentinas de EHV-1 para determinar la posible relación entre la estructura genómica y la virulencia o los signos clínicos producidos. Veinticinco cepas aisladas de diferentes casos clínicos observados entre los años 1979 y 2007 y dos cepas de referencia fueron amplifcadas y secuenciadas. El alineamiento de las secuencias se realizó con el programa Clustal X versión 1.92; el programa Bio-Edit versión 7.05 permitió deducir la secuencia de aminoácidos. Solo se observaron cambios menores, no se encontraron variaciones que pudieran estar relacionadas con la diferencia de virulencia observada previamente en el modelo ratón. No se hallaron variantes genómicas. Las regiones genómicas analizadas no permitieron diferenciar cepas abortigénicas de aquellas aisladas de muertes neonatales.
Assuntos
Animais , Camundongos , Genoma Viral , Infecções por Herpesviridae/veterinária , Herpesvirus Equídeo 1/genética , Doenças dos Cavalos/virologia , Sequência de Aminoácidos , Aborto Animal/epidemiologia , Aborto Animal/virologia , Argentina/epidemiologia , Sequência de Bases , DNA Viral/genética , Genes Virais , Cavalos , Infecções por Herpesviridae/epidemiologia , Infecções por Herpesviridae/virologia , Herpesvirus Equídeo 1/classificação , Herpesvirus Equídeo 1/isolamento & purificação , Herpesvirus Equídeo 1/patogenicidade , Doenças dos Cavalos/epidemiologia , Dados de Sequência Molecular , Fases de Leitura Aberta/genética , Alinhamento de Sequência , Homologia de Sequência do Ácido Nucleico , Especificidade da Espécie , Virulência/genéticaRESUMO
Seven conventional adult horses were inoculated intranasally with a Brazilian A4/72 strain of equid herpesvirus-1 (EHV-1). In the first ten days after the inoculation, they showed signs of a mild, self limitin gupper respiratory tract infection. In spite of the presence of neutralizing antibodies before the trial, seroconversion was observed in some horses. The virus was not isolated from nasal swabs and peripheral blood leukocytes (PBL) of any of the horses. However,the EHV-1 was detected through the polymerase chain reaction (PCR)from PBL of all horses in the experiment within the third to the eighth day after the inoculation that illustrated the viremia. In addition,the PCR assay also detected the virus in bronchoalveolar lavage fluid samples starting on the ninth day after the experimental infection in most of horses. For that reason, as a diagnostic tool, the PCR assay showed higher sensitivity and specificity than the conventional laboratorial methods in detection of EHV-1.(AU)
Sete cavalos adultos de status sanitário convencional foram inoculados por via intranasal com a estirpe brasileira A4/72 do herpesvírus eqüino tipo 1 (EHV-1). Nos primeiros dez dias após a inoculação viral, todos os cavalos apresentaram manifestações de infecção respiratória leve erestrita às vias aéreas anteriores. Apesar de possuírem títulos de anticorpos neutralizantes antes da inoculação, alguns cavalos apresentaram soroconversão após o desafio viral. O EHV-1 não foi isolado a partir das secreções nasais e leucócitos sanguíneos periféricos(PBL) de nenhum animal. Entretanto, o DNA viral foi detectado pela reação em cadeia pela polimerase (PCR) nos PBL entre o terceiro e o oitavo dias pós-inoculação (d.p.i.) em todos os animais, indicando a ocorrência de viremia. Além disso, a prova de PCR detectou o vírus nas amostras do lavado broncoalveolar a partir do nono d.p.i. na maioria dos animais. Com base nos resultados obtidos, foi possível concluir que a PCR é uma técnica com alta sensibilidade e especificidade para o diagnóstico do EHV-1, capaz de detectar a presença do DNA viral mesmo quando não ocorre a constatação do agente pelos métodos tradicionais.(AU)