Oral shedding from experimentally infected falcons with avian influenza virus.

<p>Viral RNA shedding detected by RRT-PCR in oropharyngeal swabs of falcons infected via the feeding route or via the nasochoanal route. Ct, cycle of threshold. <b>A.</b> Falcons infected with A/<i>Anas plathyrhynchos</i>/Spain/1877/2009 (H7N2) LPAI virus and euthanized at 11 dpi. <b>B.</b> Falcons infected with A/Great crested grebe/Basque Country/06.03249/2006 (H5N1) HPAI virus.</p

Distribution of α-2,3 and α-2,6 receptors in the digestive tract of falcons demonstrated by means of MAAII and SNA lectin histochemistry.

<p><b>A.</b> Proventriculus stained by MAAII lectin. <b>B.</b> Duodenum stained by MAAII lectin. <b>C.</b> Rectum stained by MAAII lectin. <b>D.</b> Proventriculus stained by SNA lectin. <b>E.</b> Duodenum stained by SNA lectin. <b>F.</b> Rectum stained by SNA lectin.</p

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.

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

Brain tissue from an experimentally H5N1 HPAI virus-inoculated falcon dead at 5 dpi.

<p><b>A.</b> Focal area of malacia in the cortex (HE stain). <b>B.</b> Immunohistochemical staining of influenza A virus antigen in brain tissue.</p

Distribution of α-2,3 and α-2,6 receptors in the respiratory tract of falcons demonstrated by means of MAAII and SNA lectin histochemistry.

<p><b>A.</b> Nasal turbinates stained by MAAII lectin. <b>B.</b> Trachea stained by MAAII lectin. <b>C.</b> Lung stained by MAAII lectin. <b>D.</b> Nasal turbinates stained by SNA lectin. <b>E.</b> Trachea stained by SNA lectin. <b>F.</b> Lung stained by SNA lectin.</p

Pancreatic macroscopic lesions from a falcon experimentally infected with highly pathogenic avian influenza virus H5N1.

<p>Multifocal hemorrhagic necrosis in the pancreas of a falcon infected via the nasochoanal route with A/Great crested grebe/Basque Country/06.03249/2006 H5N1 HPAI virus (5 dpi).</p

Viral RNA in tissues of falcons infected with A/Great crested grebe/Basque Country/06.03249/2006 (H5N1) HPAI virus.

<p>Ct, cycle of threshold; CNS, central nervous system; undet, not detected by RRT-PCR.</p

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

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

Experimental design of the study.

<p>LPAI, low pathogenic avian influenza; HPAI, highly pathogenic avian influenza; PBS, phosphate buffer saline; EID₅₀, 50% egg infectious dose; ELD₅₀, 50% egg lethal dose.</p><p>LPAI virus was A/<i>Anas plathyrhynchos</i>/Spain/1877/2009 (H7N2); HPAI virus was A/Great crested grebe/Basque Country/06.03249/2006 (H5N1).</p

Sampling effort and AIV detection in each study site and season.

<p>BM: Breeding/moult; AM/W: Autumn migration/wintering; SM: Spring migration.</p