Spatio-temporal epidemiology of highly pathogenic avian influenza outbreaks in the two deltas of Vietnam during 2003-2007.
Prev Vet Med
; 89(1-2): 16-24, 2009 May 01.
Article
em En
| MEDLINE
| ID: mdl-19232765
ABSTRACT
Outbreaks of highly pathogenic avian influenza A subtype H5N1 have occurred in Vietnam as a series of epidemic waves since December 2003. We describe the spatial and temporal patterns of the HPAI H5N1 epidemics in the Red River Delta in the north (785 outbreaks in 606 communes) and the Mekong River Delta in the south of Vietnam (1313 outbreaks in 837 communes), where the epidemics were concentrated. Throughout the study period the percentage of outbreaks affecting ducks increased steadily to a peak of 78% during the 2006/2007 epidemic in both deltas. Five of the seven epidemic waves occurred in the period of active poultry population buildup immediately prior to the Vietnamese New Year (Tet festival). Recorded outbreaks were clustered in space and time within both deltas, consistent with infection transmission occurring via a combination of local and long-distance spread. Our analyses demonstrate that the epidemiology of HPAI in Vietnam has changed over the 4-year study period, with outbreaks now occurring in the warmer months of the year and ducks featuring more prominently as affected species. To determine the relative importance of local and long-distance spread on infection transmission, precise details of outbreak location, date of onset of clinical signs, and size and composition of the poultry population at risk need to be recorded during future outbreak responses.
Texto completo:
1
Bases de dados:
MEDLINE
Assunto principal:
Surtos de Doenças
/
Transmissão de Doença Infecciosa
/
Patos
/
Virus da Influenza A Subtipo H5N1
/
Influenza Aviária
Tipo de estudo:
Etiology_studies
/
Screening_studies
Limite:
Animals
País/Região como assunto:
Asia
Idioma:
En
Revista:
Prev Vet Med
Ano de publicação:
2009
Tipo de documento:
Article
País de afiliação:
Nova Zelândia