Figure 1.

Histopathology of the eye in Marburg virus (MARV) infection. A, A venule in the iris is partially occluded by an embolus of viable, degenerate, and necrotic vacuolated macrophages, with infiltration of macrophages into the surrounding perivascular stroma and mild edema. There are rare viral intracytoplasmic inclusion bodies (arrows) (hematoxylin-eosin staining). B, Immunolabeling for MARV glycoprotein (GP) is positive in intravascular and extravascular macrophages and interstitial fibroblasts in the iris (nitroblue tetrazolium and 5-bromo-4-chloro-3-indolyl-phosphate chromagen and hematoxylin counterstain). C, MARV genome in situ hybridization (ISH) labels iridial fibroblasts and intravascular and extravascular macrophages, with scattered non–cell-associated staining (red substrate chromagen and hematoxylin counterstain). D, Positive immunostaining for MARV GP is present in morphologically normal ciliary body epithelium, stromal fibroblasts, and smooth muscle cells. Inset shows higher magnification of positive ciliary epithelium and stroma. E, Positive ISH findings for MARV genome in the epithelial cells, smooth muscle, and stroma of the ciliary body. Inset shows higher magnification of ciliary epithelium and stroma. F, Discrete foci of MARV genomic RNA are present in the inner nuclear layer of the retina.