Table 2. Distribution of influenza virus antigen in tissues of naïve juvenile Canada geese tissues after challenge with influenza virus (H5N1).

Tissue	Animal 861S/36R dpi 3*	Animal 855S/30R dpi 4*	Animal 851S/26R dpi 5*	Animal 854S/29R dpi 5*	Animal 860S/35R dpi 5*	IHC-positive cell types
Trachea	+	+	–	–	–	Vascular endothelium
Lung	++	++	–	+	–	Vascular endothelium, mononuclear cells
Esophagus	++	++	+	+	–	Epithelium, Vascular smooth muscle, Smooth muscle of muscularis externa, Mucous glands
Proventriculus	+	+	–	++	–	Epithelium (columnar, glandular), muscularis mucosa, vascular smooth muscle, parasympathetic ganglia
Ventriculus	++	++	–	++	–	Epithelium
Gut	++	+++	–	++	+	Parasympathetic ganglia, mucosal smooth muscle, vascular endothelium
Cecal tonsil	++	++	+	++	–	Parasympathetic ganglia
Pancreas	++	+++	++	++	+	Exocrine acinar cells
Liver	–	–	–	+	–	Hepatocytes
Spleen	++	–	+	–	–	Vascular smooth muscle, mononuclear cells
Kidney	+	–	–	–	–	Tubular epithelium
Muscle	+	+	–	–	–	Vascular smooth muscle
Heart	++	++	++	+	+	Myocytes
Brain	++	+++	+++	+++	+++	Neurons, glial cells, ependymal cells, choroid plexus epithelium
Spinal cord	+	++	++	++	++	Ependymal cells, neurons, glial cells, leptomeninges
Sciatic nerve	+	–	–	–	–	Vascular endothelium
Brachial nerve	–	–	–	–	–	None

*Numbers of immunohistochemically positive cells: +, few; ++, moderate; +++, numerous; –, virus antigen negative; dpi, days postinfection.