Avian influenza virus (H11N9) in migratory shorebirds wintering in the Amazon region, Brazil

Aquatic birds are the natural reservoir for avian influenza viruses (AIV). Habitats in Brazil provide stopover and wintering sites for water birds that migrate between North and South America. The current study was conducted to elucidate the possibility of the transport of influenza A viruses by birds that migrate annually between the Northern and Southern Hemispheres. In total, 556 orotracheal/cloacal swab samples were collected for influenza A virus screening using real-time RT-PCR (rRT-PCR). The influenza A virus-positive samples were subjected to viral isolation. Four samples were positive for the influenza A matrix gene by rRT-PCR. From these samples, three viruses were isolated, sequenced and characterized. All positive samples originated from a single bird species, the ruddy turnstone (Arenaria interpres), that was caught in the Amazon region at Caeté Bay, Northeast Pará, at Ilha de Canelas. To our knowledge, this is the first isolation of H11N9 in the ruddy turnstone in South America. (Résumé d'auteur

Phylogenetic analysis of neuraminidase of the influenza A virus.

<p>Trees were generated by PAUP 4.0b10 using the maximum likelihood algorithm with the parameters indicated by the GTR Modeltest (bootstrap values are shown for the branch points). The scale bar is shown on the bottom left. In this study, sequences that were available in public databases were used to construct the tree, and the accession numbers along with their branch data are shown.</p

Phylogenetic analysis of the hemagglutinin gene of the influenza A virus.

<p>Trees were generated by PAUP 4.0b10 using the maximum likelihood algorithm with the parameters indicated by the GTR Modeltest (bootstrap values are shown for the branch points). The scale bar is shown on the bottom left. In this study, sequences that were available in the public database were used to construct the tree, and the accession numbers along with their branch data are shown.</p

Location of sampling sites along the Brazilian coast in relation to the main migration routes and congregation sites of ruddy turnstones in North and South America.

<p>Samples were collected in Jan-May and Aug-Dec from 2006 to 2010. (map by M. Gély ©Cirad, adapted from Wings Over Wetlands UNEP-GEF Flyways Project and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0110141#pone.0110141-Blanco1" target="_blank">[34]</a>.</p

Surveillance of influenza A viruses in wild birds in Brazil by real-time RT-PCR.

<p>*Sample type: C =  Cloacal, O =  Oral and F =  Feces.</p><p>Surveillance of influenza A viruses in wild birds in Brazil by real-time RT-PCR.</p

Primers used to sequence the complete NA gene.

<p>Primers used to sequence the complete NA gene.</p

Primers used to sequence the complete HA gene.

<p>Primers used to sequence the complete HA gene.</p

The closest sequences to NA of influenza A virus available in public databases based on percent nucleotide similarity.

<p>The closest sequences to NA of influenza A virus available in public databases based on percent nucleotide similarity.</p