Average distribution of nucleoprotein antigen, as determined by immunohistochemistry, in tissues sampled from falcons infected via the nasochoanal route with A/Great crested grebe/Basque Country/06.03249/2006 (H5N1) HPAI virus.

Abstract

<p>− = no positive cells; + = single positive cells; ++ = scattered groups of positive cells; +++ = widespread positivity.</p><p>NSL, no significant lesions; nd, not determined.</p