Fig 8.

Pulmonary lesions associated with aerosolized SUDV. (A) Dorsal view of lungs and trachea (T) from experimental animal 13, after removal from the thoracic cavity. There is diffuse pulmonary edema and a large area of dark-red consolidation (arrow) in the caudal aspect of the left superior lung lobe (S). The pleural surface in this area and the left middle lung lobe (M) is covered with tan-white fibrinous exudate which causes adhesions between the left superior, middle, and inferior (I) lung lobes. (B) Histologic section of normal lung from a cynomolgus macaque that died after i.m. challenge with SUDV. Clear spaces are alveoli and are separated by thin-walled septa and small blood vessels (V). (C) Histologic section of lung from control animal 12, which died 7 days after challenge with aerosolized SUDV. The alveoli are filled by edema fluid, fibrin, and a mixture of macrophages, neutrophils, and red blood cells. Alveolar septa are congested and thickened with inflammatory cells. A small arteriole (A) is also present. (D) IHC of lung from control animal 12 reveals the presence of abundant intracellular and extracellular ebolavirus antigen (brown staining). (E) Histologic section of a pulmonary granuloma in experimental animal 18, which survived a challenge with aerosolized SUDV. The center of the granuloma (left 1/3 of the photo) contains suppurative inflammation, fibrin, and necrotic debris. The wall of the granuloma (right 2/3 of the photo) is composed of macrophages, lymphocytes, plasma cells, and fibrous connective tissue. (F) IHC of a replicate section of the image in panel E reveals ebolavirus antigen within macrophages and scattered extracellular antigen in the area of necrosis. Objective magnifications (B to F), ×20.