Temporal variation in IAV prevalence among Portuguese ducks during the period 2008–2009.

<p>(A) Overall temporal variation in IAV prevalence among sampled ducks. (B) The percentage of IAV-positives among juvenile and adult ducks in Portugal. Prevalence numbers are derived from sample screenings where IAV was detected by RRT-PCR.</p

Bayesian phylogenetic tree showing relationships among H11 influenza A viruses isolated in this study and publicly available sequences from GenBank.

<p>The Portuguese sequence is shown with bold font and the clade containing North American sequences is indicated. The tree is rooted at the midpoint and numbers at nodes indicate posterior probability support. The scale bar indicates substitutions per site.</p

Bayesian phylogenetic tree showing relationships among H10 influenza A viruses isolated in this study and publicly available sequences from GenBank.

<p>The clades containing Portuguese and North American sequences are indicated, and Portuguese isolates are shown in bold. The tree is rooted at the midpoint and numbers at nodes indicate posterior probability support. The scale bar indicates substitutions per site.</p

Results from IAV screening and isolation of samples taken in Portugal 2008–2009.

a<p>The sequences of two additional H9N2 viruses were determined by sequencing the viral H and N segments in the original sample.</p>b<p>Number of different subtypes identified.</p

Bayesian phylogenetic tree showing relationships among H9 influenza A viruses isolated in this study and publicly available sequences from GenBank.

<p>The clade including the Portuguese sequences, as well as some well-established H9N2 linages (Korea, G1 and Y280) are indicated. In addition, isolates associated with infections in humans and swine have been indicated by underlining and italics, respectively. The tree is rooted at the midpoint and numbers at nodes indicate posterior probability support. The scale bar indicates substitutions per site.</p