Severe Outbreak of Avian Encephalomyelitis in Laying Hens in Northeastern Brazil
Autor(a) principal: | |
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Data de Publicação: | 2019 |
Outros Autores: | , , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Brazilian Journal of Poultry Science (Online) |
Texto Completo: | http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1516-635X2019000200305 |
Resumo: | ABSTRACT This paper describes the epidemiological, clinical and pathological aspects of an avian encephalomyelitis (AE) outbreak in commercial laying hens in Northeastern Brazil. The disease affected 23,409 layers (from day one until 100 weeks) leading to mortality of 16.5% (5,049/30,600) of the flock. Twenty laying hens were clinically examined, and blood samples were collected and tested by Enzyme-Linked Immunosorbent Assay (ELISA). Five laying hens with neurological signs were necropsied and samples of the brain, cerebellum, spinal cord, sciatic nerve, heart, ceca tonsils, proventriculus and liver were collected, fixed in formalin buffered solution and processed according to routine methods for histological examination. Clinical signs were observed in approximately 60% of the chicken flock and included depression, ataxia, head and neck tremors, head tilt, motor incoordination and corneal opacity and of lens. All laying hens presented seroconversion for AE, with a geometric mean titer (GMT) of 6,854 and CV of 9.6%. At necropsy, there were bilateral opacity of the cornea and lens and the blood vessels of the cerebral cortex were hyperemic. The main microscopic lesions in the central nervous system consisted of red and shrunken neurons in the cerebral cortex, cerebellum and spinal cord. Significant areas of gliosis were observed in the cerebral cortex and in the molecular layer of the cerebellum. Hyperplasia of the proventricular lymphoid tissue and the ceca tonsils were observed with different degrees of intensity. In Northeastern Brazil, there haven’t been previous reports of AE in commercial laying hens and this outbreak possibly occurred by inefficient immunization of laying breeders at the genetic supply company. |
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Severe Outbreak of Avian Encephalomyelitis in Laying Hens in Northeastern BrazilAvian encephalomyelitisbirdslaying hensnonsuppurative encephalomyelitisvaccinationABSTRACT This paper describes the epidemiological, clinical and pathological aspects of an avian encephalomyelitis (AE) outbreak in commercial laying hens in Northeastern Brazil. The disease affected 23,409 layers (from day one until 100 weeks) leading to mortality of 16.5% (5,049/30,600) of the flock. Twenty laying hens were clinically examined, and blood samples were collected and tested by Enzyme-Linked Immunosorbent Assay (ELISA). Five laying hens with neurological signs were necropsied and samples of the brain, cerebellum, spinal cord, sciatic nerve, heart, ceca tonsils, proventriculus and liver were collected, fixed in formalin buffered solution and processed according to routine methods for histological examination. Clinical signs were observed in approximately 60% of the chicken flock and included depression, ataxia, head and neck tremors, head tilt, motor incoordination and corneal opacity and of lens. All laying hens presented seroconversion for AE, with a geometric mean titer (GMT) of 6,854 and CV of 9.6%. At necropsy, there were bilateral opacity of the cornea and lens and the blood vessels of the cerebral cortex were hyperemic. The main microscopic lesions in the central nervous system consisted of red and shrunken neurons in the cerebral cortex, cerebellum and spinal cord. Significant areas of gliosis were observed in the cerebral cortex and in the molecular layer of the cerebellum. Hyperplasia of the proventricular lymphoid tissue and the ceca tonsils were observed with different degrees of intensity. In Northeastern Brazil, there haven’t been previous reports of AE in commercial laying hens and this outbreak possibly occurred by inefficient immunization of laying breeders at the genetic supply company.Fundacao de Apoio a Ciência e Tecnologia Avicolas2019-01-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersiontext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S1516-635X2019000200305Brazilian Journal of Poultry Science v.21 n.2 2019reponame:Brazilian Journal of Poultry Science (Online)instname:Fundação APINCO de Ciência e Tecnologia Avícolas (FACTA)instacron:FACTA10.1590/1806-9061-2018-0749info:eu-repo/semantics/openAccessRocha,PMCBarros,MEGRocha,BPSouza,FALMendonça,FSEvêncio-Neto,Jeng2019-08-14T00:00:00Zoai:scielo:S1516-635X2019000200305Revistahttp://www.scielo.br/rbcahttps://old.scielo.br/oai/scielo-oai.php||rvfacta@terra.com.br1806-90611516-635Xopendoar:2019-08-14T00:00Brazilian Journal of Poultry Science (Online) - Fundação APINCO de Ciência e Tecnologia Avícolas (FACTA)false |
dc.title.none.fl_str_mv |
Severe Outbreak of Avian Encephalomyelitis in Laying Hens in Northeastern Brazil |
title |
Severe Outbreak of Avian Encephalomyelitis in Laying Hens in Northeastern Brazil |
spellingShingle |
Severe Outbreak of Avian Encephalomyelitis in Laying Hens in Northeastern Brazil Rocha,PMC Avian encephalomyelitis birds laying hens nonsuppurative encephalomyelitis vaccination |
title_short |
Severe Outbreak of Avian Encephalomyelitis in Laying Hens in Northeastern Brazil |
title_full |
Severe Outbreak of Avian Encephalomyelitis in Laying Hens in Northeastern Brazil |
title_fullStr |
Severe Outbreak of Avian Encephalomyelitis in Laying Hens in Northeastern Brazil |
title_full_unstemmed |
Severe Outbreak of Avian Encephalomyelitis in Laying Hens in Northeastern Brazil |
title_sort |
Severe Outbreak of Avian Encephalomyelitis in Laying Hens in Northeastern Brazil |
author |
Rocha,PMC |
author_facet |
Rocha,PMC Barros,MEG Rocha,BP Souza,FAL Mendonça,FS Evêncio-Neto,J |
author_role |
author |
author2 |
Barros,MEG Rocha,BP Souza,FAL Mendonça,FS Evêncio-Neto,J |
author2_role |
author author author author author |
dc.contributor.author.fl_str_mv |
Rocha,PMC Barros,MEG Rocha,BP Souza,FAL Mendonça,FS Evêncio-Neto,J |
dc.subject.por.fl_str_mv |
Avian encephalomyelitis birds laying hens nonsuppurative encephalomyelitis vaccination |
topic |
Avian encephalomyelitis birds laying hens nonsuppurative encephalomyelitis vaccination |
description |
ABSTRACT This paper describes the epidemiological, clinical and pathological aspects of an avian encephalomyelitis (AE) outbreak in commercial laying hens in Northeastern Brazil. The disease affected 23,409 layers (from day one until 100 weeks) leading to mortality of 16.5% (5,049/30,600) of the flock. Twenty laying hens were clinically examined, and blood samples were collected and tested by Enzyme-Linked Immunosorbent Assay (ELISA). Five laying hens with neurological signs were necropsied and samples of the brain, cerebellum, spinal cord, sciatic nerve, heart, ceca tonsils, proventriculus and liver were collected, fixed in formalin buffered solution and processed according to routine methods for histological examination. Clinical signs were observed in approximately 60% of the chicken flock and included depression, ataxia, head and neck tremors, head tilt, motor incoordination and corneal opacity and of lens. All laying hens presented seroconversion for AE, with a geometric mean titer (GMT) of 6,854 and CV of 9.6%. At necropsy, there were bilateral opacity of the cornea and lens and the blood vessels of the cerebral cortex were hyperemic. The main microscopic lesions in the central nervous system consisted of red and shrunken neurons in the cerebral cortex, cerebellum and spinal cord. Significant areas of gliosis were observed in the cerebral cortex and in the molecular layer of the cerebellum. Hyperplasia of the proventricular lymphoid tissue and the ceca tonsils were observed with different degrees of intensity. In Northeastern Brazil, there haven’t been previous reports of AE in commercial laying hens and this outbreak possibly occurred by inefficient immunization of laying breeders at the genetic supply company. |
publishDate |
2019 |
dc.date.none.fl_str_mv |
2019-01-01 |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1516-635X2019000200305 |
url |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1516-635X2019000200305 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
10.1590/1806-9061-2018-0749 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
text/html |
dc.publisher.none.fl_str_mv |
Fundacao de Apoio a Ciência e Tecnologia Avicolas |
publisher.none.fl_str_mv |
Fundacao de Apoio a Ciência e Tecnologia Avicolas |
dc.source.none.fl_str_mv |
Brazilian Journal of Poultry Science v.21 n.2 2019 reponame:Brazilian Journal of Poultry Science (Online) instname:Fundação APINCO de Ciência e Tecnologia Avícolas (FACTA) instacron:FACTA |
instname_str |
Fundação APINCO de Ciência e Tecnologia Avícolas (FACTA) |
instacron_str |
FACTA |
institution |
FACTA |
reponame_str |
Brazilian Journal of Poultry Science (Online) |
collection |
Brazilian Journal of Poultry Science (Online) |
repository.name.fl_str_mv |
Brazilian Journal of Poultry Science (Online) - Fundação APINCO de Ciência e Tecnologia Avícolas (FACTA) |
repository.mail.fl_str_mv |
||rvfacta@terra.com.br |
_version_ |
1754122514799263744 |