H&E histological analysis of tissues from WNV-infected hamsters.

NS: No significant histological lesions.A: Mild focal acute degeneration of the tunica media of a large vessel adjacent to the right atrium. Mixed cell marginalization along the intima of this vessel. Moderate numbers of lymphocytes and plasma cells infiltrate connective tissue bordering the affected vessel wall.B: Hydropic degeneration of hepatocytes.C: Scattered small groups of hepatocytes containing single to multiple, small intracytoplasmic lipid vacuoles.D: Moderate numbers of mixed mononuclear cells including a population of eosinophils and histiocytes containing dull basophilic intracytoplasmic material.E: Localized neutrophilic infiltration of the tissue anchoring the valvular leaflets on the left side.F: Moderate aggregates of lymphocytes and fewer plasma cellular infiltrate the myocardium of the interventricular septum (cranial) and the tip of the right ventricular wall (approximately the AV junction).G: In colon, segmental moderate infiltration of the muscularis mucosa by bands of neutrophils.