Histopathological and immunohistochemical studies of lesions associated with Ebola virus in a naturally infected chimpanzee

Lesions caused by the Cote d'Ivoire subtype of Ebola virus in a naturally i nfected young chimpanzee were characterized by histopathological and immuno histochemical methods. The predominant lesions consisted of multifocal necr osis in the liver and diffuse fibrinoid necrosis in the red pulp of the spl een. In these sites, macrophages contained large eosinophilic intracytoplas mic inclusion bodies. Immunohistochemical staining indicated that macrophag es were a major site of viral replication. The absence of bronchiolar and p ulmonary lesions and the paucity of antigen-containing macrophages in the l ung suggested that aerosol transmission by this animal was unlikely. There were necrotic foci and antigen-containing macrophages in intestinal lymph n odes, in association with lesions caused by intestinal parasites, suggestin g the possibility of virus entry through the digestive tract.