Canarypox virus

Canarypox virus (CNPV) is an Avipoxvirus and etiologic agent of canarypox, a disease of wild and captive birds that can cause significant losses. Canarypox can enter human cells, but it cannot survive and multiply in human cells. There is a live viral vaccine available which may have beneficial properties against human cancer when used as a mammalian expression vector. (ATCvet code: QI01KD01 (WHO)). Furthermore, the POXIMUNE® C vaccine does offer direct protection against CNPV in susceptible birds. Generally CNPV is considered a disease of songbirds, such as canaries, magpies and nightingales, and is associated with higher mortality rates when compared to other avian pox viruses. In some instances, mortality approaches 100%. Avian pox viruses also cause significant economic losses in domestic poultry and remain a problem in the conservation of endemic bird species inhabiting islands. The general symptoms of CNPV are similar to those of other species of avian pox viruses and are characterised by pustules and diphtheria or pneumonia-like symptoms. Canarypox virus (CNPV) is a member of the Poxviridae family. Canarypox viruses, as with other bird pox viruses, are in the genera of Avipoxvirus. Nine other species are also in the genus Avipoxvirus. These include: Fowlpox virus, Juncopox virus, Mynahpox virus, Psittacinepox virus, Sparrowpox virus, Starlingpox virus, Pigeonpox virus, Turkeypox virus and Quailpox virus. It has thus far been reported that around 232 bird species (from 23 disparate orders) are affected by avian pox virus. CNPV is an enveloped virus. They can be enveloped by double (external enveloped virion- EEV) or single (intracellular mature virion – IMV) membranes. These membranes are acquired from the host cell's endoplasmic reticulum (ER) or cell membrane. CNPV and other poxviruses are characterised by having exceptionally large physical dimensions, approximately 330 nm×280 nm×200 nm. The genome of CNPV is linear and is composed of dsDNA. The genome size is approximately 365kbp, and in total, 328 genes have been found. The shape of all poxviruses resembles something of a 'rounded brick' and remains determined by the specific envelope around the virus. The process which further characterises the poxvirus family is that replication occurs in the cytoplasm and utilises a specific virus-made structure for replication, the 'virosome'.