Genetic and antigenic characterization of H5, H6 and H9 avian influenza viruses circulating in live bird markets with intervention in the center part of Vietnam.
Vet Microbiol
; 192: 194-203, 2016 Aug 30.
Article
em En
| MEDLINE
| ID: mdl-27527783
ABSTRACT
A total of 3,045 environmental samples and oropharyngeal and cloacal swabs from apparently healthy poultry have been collected at three live bird markets (LBMs) at which practices were applied to reduce avian influenza (AI) virus transmission (intervention LBMs) and six conventional LBMs (non-intervention LBMs) in Thua Thien Hue province in 2014 to evaluate the efficacy of the intervention LBMs. The 178 AI viruses, including H3 (19 viruses), H4 (2), H5 (8), H6 (30), H9 (114), and H11 (5), were isolated from domestic ducks, muscovy ducks, chickens, and the environment. The prevalence of AI viruses in intervention LBMs (6.1%; 95% CI 5.0-7.5) was similar to that in non-intervention LBMs (5.6%; 95% CI 4.5-6.8; χ(2)=0.532; df=1; P=0.53) in the study area. Eight H5N6 highly pathogenic avian influenza (HPAI) viruses were isolated from apparently healthy ducks, muscovy ducks, and an environmental sample in an intervention LBM. The hemagglutinin genes of the H5N6 HPAI viruses belonged to the genetic clade 2.3.4.4, and the antigenicity of the H5N6 HPAI viruses differed from the H5N1 HPAI viruses previously circulating in Vietnam. Phylogenetic and antigenic analyses of the H6 and H9 viruses isolated in both types of LBMs revealed that they were closely related to the viruses isolated from domestic birds in China, Group II of H6 viruses and Y280 lineage of H9 viruses. These results indicate that the interventions currently applied in LBMs are insufficient to control AI. A risk analysis should be conducted to identify the key factors contributing to AI virus prevalence in intervention LBMs.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Vírus da Influenza A
/
Galinhas
/
Patos
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Influenza Aviária
/
Antígenos Virais
Tipo de estudo:
Prognostic_studies
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Risk_factors_studies
Limite:
Animals
País/Região como assunto:
Asia
Idioma:
En
Revista:
Vet Microbiol
Ano de publicação:
2016
Tipo de documento:
Article
País de afiliação:
Vietnã