EPIDEMIOLOGICAL AND ULTRASTRUCTURAL STUDIES ON PIGEON POX IN UPPER EGYPT

exotic birds The occurrence of pox virus infections in three species of including pigeons, house sparrows (Passere domesticus) and doves was studied. Isolated pox viruses were identified physicochemically, biologically (host spectrum) and serologically. Isolates from pigeons and doves were characterized as pigeon pox virus, while the sparrows isolate was
characterized as fowl pox virus. It seemed that doves are reservoir of infection to pigeons. Histopathological examination revealed that pigeon pox virus infection in pigeons resulted in epidermal hyperplasia with associated inflammatory reaction and formation of eosinophilic intracytoplasmic A-type inclusion bodies in the epithelial cells. Electron microscopic studies revealed that infected cells showed areas of viroplasm which was sequestrated to form viroplasmic particles. Maturation of these particles occurred by projection into the membrane of inclusion body vacuole where they obtain a membrane coat and arrangement of rodlets over the surface of the virion to form the external coat in the interior of the inclusion body. Experimental infection of pigeons with pigeon pox virus was manifested clinically by generalized cutaneous lesions which were more severe after intravenous (i.v.) inoculation than after the feather follicle route.