Pathology and diagnosis of mousepox

The pathologic changes of mousepox were studied during an outbreak at the National Institutes of Health in 1979. The most consistent lesions were necrosis of lymphatic tissues, especially the spleen, lymph nodes, and Peyer's patches. Hepatic necrosis and jejunal hemorrhage also were found. In two transmission studies, the disease was experimentally induced in BALB/cAnN and C3H/HeN-nu mice. Athymic mice were found to be highly susceptible, and they developed fulminant disease. The diagnosis was confirmed by demonstration of pox virions in infected tissues by electron microscopy, staining of viral antigen by immunoperoxidase methods, and by isolation of the virus in chorioallantoic membranes of hen's eggs and in cultures of chick embryonic cells.