Table 3.

Average distribution of AIV-NP antigen in positive tissues from quail intranasally challenged with H7N1/HP

Tissue*	3 dpi	5 dpi	8 dpi	15 dpi	Predominant cell types	Associated lesion
Gizzard	–	++	–	–	Epithelial cells of the ventricular glands	Severe multifocal necrosis, mild lymphoplasmacytic infiltrate
Cecal tonsil	–	+	–	–	Epithelial cells of the glands, cells of the muscularis externa	Focal necrosis, mild lymphoplasmacytic infiltrate
Pancreas	–	++	+++	–	Acinar cells, endothelial cells	Severe multifocal to coalescent lytic necrosis, lymphoplasmacytic infiltrate, edema
Nasal turbinates	+	–	–	–	Respiratory epithelial cells	Lymphoplasmacytic infiltrate in lamina propria
Trachea	–	+	–	–	Goblet cells	NSL
Heart	–	++	–	–	Myocardiocytes, endothelial cells	Severe multifocal necrosis, mild lymphoplasmacytic infiltrate
Spleen	–	+	+	–	Endothelial cells, macrophages	NSL
Brain	–	+++	++	–	Neurons, Purkinje cells, ependymal cells, glial cells, endothelial cells	Malacia in cortex, necrosis of ependymal cells of ventricles and epithelial cells of choroid plexus, chromatolysis of Purkinje cells, lymphoplasmacytic infiltrate
Spinal cord	–	+++	–	–	-	Malacia in grey matter, necrosis of the ependyma and neuropil

*Tissues not present appeared overtly normal on histopathological analysis and did not show positive IHC staining.

– = no positive cells; + = single positive cells; ++ = scattered groups of positive cells; +++ = widespread positivity.

dpi, days post-inoculation; NSL, no significant lesions.