Ducks and the risk of avian influenza in Portugal

• Autor(a) principal: Fabião, António
• Data de Publicação: 2006
• Outros Autores: Rodrigues, David, Figueiredo, Maria Ester, Encarnação, Vitor
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.5/1380
• topic: duck; avian influenza; Portugal

The outbreak of highly pathogenic avian influenza of the H5N1 virus subtype in Western European countries induced the fear that it could reach Portugal through wild bird migration. Ducks, geese and swans are some of the bird groups with higher prevalence of influenza virus that might be vectors of virus dissemination, considering the existing studies on low pathogenic subtypes that are common in nature (Olsen et al. 2006), and also occur in Portugal (D. Rodrigues et al., unpublished data). Although swans do not occur frequently in Portugal and geese are mostly restricted to Tagus River Estuary Nature Reserve (e.g. Farinha & Costa 1999), ducks are common in Portugal and mostly concentrated on wetlands near the coast (Costa & Guedes 1997), and wintering Aythya duck species are much less numerous than wintering Anas species (e.g. Costa & Guedes 1997). The Portuguese total wintering duck population (Costa & Guedes 1997) is relatively small when compared to the total European population (Scott & Rose 1996), probably due to the location of the country on the South-West limit of the distribution for most of the species (Scott & Rose 1996). However, given the recent occurrence of outbreaks of highly pathogenic avian influenza of the H5N1 subtype in France, Germany, Scotland, Denmark, Sweden and Poland (OIE 2006), there is a risk that outbreaks may also occur in Portugal. In this paper, we aim to discuss the possibility of avian influenza occurrence in Portugal, under the assumptions that outbreaks will persist, will occur new ones or the virus will become endemic on the above mentioned countries and that ducks will be vectors of the virus