Avian Pox Viruses
Deoki N. Tripathy
from: Avian Virology: Current Research and Future Trends (Edited by: Siba K. Samal). Caister Academic Press, U.K. (2019) Pages: 365-376.
Avian pox viruses infect both wild and domestic birds. In this regard, more information is available on fowlpox virus type species of the genus Avipoxvirus because of its economic impact on commercial poultry. Canarypox virus infection causes high mortality in canaries. The diagnosis is based on the development of cutaneous and/or diphtheritic lesions and histopathologic examination of the lesions for cytoplasmic inclusions. The virus multiplies in the cytoplasm of infected cells and produces cytoplasmic inclusion bodies. Virus isolation is carried out in the developing chicken embryos. Complete nucleotide sequence of the genomes of fowlpox virus, canarypox virus and few other avian pox viruses has been determined. Polymerase chain reaction (PCR) is being used to amplify nucleotide sequences of specific genes, e.g. 4b, for diagnosis and phylogenetic analysis of strains. For disease prevention, vaccines of fowlpox and pigeonpox virus origin have been used for many years by the poultry industry. Outbreaks of fowlpox in previously vaccinated chickens still occur in many poultry operations. The virus strains isolated from such outbreaks show insertion of full-length reticuloendotheliosis virus (REV) in their genome. REV has been associated with immunosuppression and tumor formation. It appears that the emerging strains are antigenically and genetically different for which the current vaccines do not provide adequate protection read more ...