Highly Pathogenic Avian Influenza Virus (H5N1) Infection in Red Foxes Fed Infected Bird Carcasses
Figure 2. Lesions and associated expression of influenza virus antigen in respiratory and extrarespiratory organs of foxes infected intratracheally with HPAI virus (H5N1), at 7 days postinoculation. A) Lungs of control fox sham-inoculated with phosphate-buffered saline. B) Lungs of intratracheally inoculated fox presenting extensive consolidated lesions (darkened areas), characterized by C) diffuse alveolar damage and regeneration (type II pneumocyte hyperplasia) and D) expression of influenza virus antigen in the nucleus and, to a lesser extent, cytoplasm of mononuclear and epithelial cells. E) Focus of inflammation and cardiomyocytic necrosis in the heart, associated with F) expression of influenza virus antigen in the nucleus of cardiomyocytes. G) Focus of gliosis and neuronal necrosis in the cerebrum, associated with H) expression of influenza virus antigen in the nucleus and, to a lesser extent, cytoplasm of glial cells and neurons. Panels C–H, original magnification ×40.