Contagious Papular Dermatitis of Japanese Serows in Niigata Prefecture

From 1990 to 1994 in Niigata Prefecture, five Japanese serows were shown to have contagious papular dermatitis, characterized by formation of papules on the lips, feet and sometimes around the nostrils, eyes and ears. Histopathology revealed vacuolar or degeneration of the prickle cells with basophilic or eosinophilic cytoplasmic inclusion bodies and necrotized and purulent dermatitis with marked hyperkeratosis. Orf virus antigen was demonstratedwithin inclusion bodies by immunostain, and numerous viral particles, oval to cylindricalin shape and 147 to 287nm in size, were observed in the cytoplasm of epidermal cells by electron microscopy. In the lips of a sheep intracutaneously inoculated with suspensions of the papular lesion of an affected serow, papillary lesions with cytoplasmic inclusions bodies were produced in 2 weeks since.