Outbreak of infectious laryngotracheitis in large multi-age egg layer chicken flocks in Minas Gerais, Brazil
| Autor: | Rodrigo M. Couto, Roselene Ecco, Juliana Fortes Vilarinho Braga, Ingred S. Preis, Nelson Rodrigo da Silva Martins, Bruno S. A. F. Brasil |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2013 |
| Předmět: |
medicine.medical_specialty
Gallid herpesvirus 1 Conjunctiva Population herpesvirus tipo 1 dos galináceos Galinhas de postura Virus medicine histopatologia conventional PCR Laying hen education education.field_of_study lcsh:Veterinary medicine General Veterinary biology avian infectious laryngotracheitis Outbreak sequencing biology.organism_classification Virology sequenciamento medicine.anatomical_structure Paranasal sinuses histopathology lcsh:SF600-1100 Histopathology Flock laringotraqueite infecciosa das aves PCR convencional |
| Zdroj: | Pesquisa Veterinária Brasileira, Vol 33, Iss 5, Pp 591-596 (2013) Pesquisa Veterinária Brasileira v.33 n.5 2013 Pesquisa Veterinária Brasileira Colégio Brasileiro de Patologia Animal (CBPA) instacron:EMBRAPA |
| ISSN: | 1678-5150 |
| Popis: | A recent (November 2010) outbreak of infectious laryngotracheitis (ILT) in a multi-age laying hen facility in Minas Gerais state, Brazil, is described. Previous ILT outbreak in laying hens was only notified in São Paulo state, Brazil, in 2002. In the outbreak described here, the affected population was approximately eight million hens, with flock sizes ranging from 100,000 to 2,900,000 chickens. The average mortality ranged from 1 to 6%, and morbidity was around 90% (most of the twenty seven farms of the area were positive for ILT virus). Three multi-age laying farms from one company were selected for this report. Clinical signs included prostration, dyspnea, conjunctivitis, occasional swelling of the paranasal sinuses and bloody mucous nasal discharge. Severely affected chickens presented with dyspnea, gasping and became cyanotic before death. At necropsy, these chickens had fibrinous exudate blocking the larynx and the lumen of cranial part of the trachea. In addition, conjunctivitis with intense hyperemia, edema and sinuses with caseous exudate were present. On histopathology, there were marked necrosis and desquamation of respiratory ephitelium and conjunctiva with numerous syncytial cells formation and fibrinous exudate. Moderate to marked non suppurative (especially lymphocytes and plasma cells) infiltration in the lamina propria also was observed. Sixteen out of 20 examined chickens, eosinophilic intranuclear inclusion bodies were observed in the syncytial cells. The DNA extracted from larynx and trachea produced positive PCR results for ILT virus (ILTV) DNA using formalin-fixed, paraffin embedded (FFPE) samples. Amplicons from a small region of ICP4 gene were submitted to sequencing and showed 100% identity with ILTV EU104910.1 (USA strain), 99% with ILTV JN596963.1 (Australian strain) and 91% with ILTV JN580316.1 (Gallid herpesvirus 1 CEO vaccine strain) and JN580315.1 (Gallid herpesvirus 1 TCO vaccine strain). |
| Databáze: | OpenAIRE |
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