Avipoxvirus

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Avipoxvirus
Virus classification Red Pencil Icon.png
(unranked): Virus
Realm: Varidnaviria
Kingdom: Bamfordvirae
Phylum: Nucleocytoviricota
Class: Pokkesviricetes
Order: Chitovirales
Family: Poxviridae
Subfamily: Chordopoxvirinae
Genus:Avipoxvirus
Species

See text

Avipoxvirus (avian pox) is a genus of viruses within the family Poxviridae . Poxviridae is the family of viruses which cause the afflicted organism to have poxes as a symptom. Poxviruses have generally large genomes, and other such examples include smallpox and monkeypox. Members of the genus Avipoxvirus infect specifically birds. Avipoxviruses are unable to complete their replication cycle in non-avian species. [1] Although it is comparably slow-spreading, Avipoxvirus is known to cause symptoms like pustules full of pus lining the skin and diphtheria-like symptoms. These diphtheria-like symptoms might include diphtheric necrotic membranes lining the mouth and the upper respiratory tract. Like other avian viruses, it can be transmitted through vectors mechanically such as through mosquitoes. [2] There is no evidence that this virus can infect humans. [3]

Contents

Avipoxvirus is a virus that is brick-shaped and is usually 200  nanometres in diameter. This is much larger than many other viruses, which may be around 60 nanometres in diameter. This virus can be contracted only through vectors and consumption of infected items, but they can be filtered by a special water filter. This filter is called a Large Volume Water Sampler (LVWS).

Unlike other viruses, Avipoxvirus can withstand extreme dryness. With this advantage, it can spread on dust particles. This is because it has adapted to living in the dry mucous membranes of an infected host's upper respiratory tract.

The effects of this virus might increase the difficulty of breathing, eating, and drinking significantly. Exterior lesions usually are restricted to the nonfeathered parts of the body, especially the face and legs, where there is the characteristic proliferative and necrotizing dermatitis. [4] Another feature of this bird pox that has been observed is the presence of blood sacs or blisters filled with bloody fluid that will collapse when pierced with a needle and allowed to drain. [5] This virus has the highest mortality rate in upland game birds such as pheasant, quail, and chukar partridge, as well as in songbirds, seabirds such as gulls, parrots, and some raptors such as the peregrine falcon.

History and prevalence

Avipoxviruses affect more than 230 species of wild and domestic birds worldwide. [6] It affects a variety of birds including chickens, turkeys, songbirds, upland game birds, seabirds, pets, and occasionally raptors, but is rarely found in waterfowl or shore birds. Its prevalence among wild populations is unknown due to lack of studies It is most common in temperate (warm and humid) climates. All cases in North America have been relatively recent. The United States Geological Survey has reported an increased number of cases in multiple countries with new affected bird species added in recent years. This suggests avian pox is an emerging viral disease. [7]

Mosquitoes that feed on birds are the most consistent and efficient transmitters of the virus. There appears to be a relationship between this virus and seasonal mosquito cycles. For example, in California and Oregon, prevalence is lowest in the dry summer months than the wetter seasons of autumn and winter. However, more research is required to test this hypothesis. [7]

Transmission

Mosquitoes are the most common vectors for transmission of the Avipoxvirus. Transmission occurs when a mosquito feeds on a bird in which the virus is circulating in the bloodstream or feeds near secretions from lesions. When the mosquito moves to a susceptible host and feeds, the new host is infected with the virus. The virus can also be transmitted indirectly by contaminated surfaces or airborne particles. Infections occur when the contaminated particles come in contact with mucous membranes or skin abrasions. [7] While transmission by mosquitoes has been effective at spreading the virus in a localized setting, the transmission between infected individuals has allowed the virus to spread across long distances.[ citation needed ]

Avian pox viruses appear to be family or order specific, that is, a pox virus infecting gamebirds is not likely to infect songbirds and vice versa. [6] There is no known evidence of any avian pox virus strain transmissible to humans. [8]

Avipoxvirus infection in a Laysan albatross chick LAchickwithPox-WRH.jpg
Avipoxvirus infection in a Laysan albatross chick

Clinical signs

Lesions of the skin and diphtheritic membrane of the respiratory tract are common when domesticated and wild birds are infected with the Avipoxvirus. [9] There are two common forms of clinical signs. Cutaneous pox are most common. They appear as wart-like growths around the eyes and other apterylae (feather-free) areas, sometimes in large clusters. Pock lesions can be concentrated or spread out. [9] The size and number of growths depend on the severity of the infection. [10] Diphtheritic, or wet, pox are characterized as raised yellow blemishes on mucous membranes of the mouth, esophagus, trachea, and lungs. These can lead to difficulty breathing or swallowing. In both cases, birds may appear weak and emaciated. [10]

The infection of Avipoxvirus can lead to decreased egg production, reduced growth, blindness, and increased mortality in domestic poultry. In wild bird species, elevated predation, secondary infections, trauma, reduced male mating success, and death are common results. [9]

Prevention and control

Avian pox viruses are contagious pathogens, and once introduced into a captive community, can spread very quickly. [7] The recommended method of preventing transmission is to prevent standing water in the environment (i.e., to avoid mosquitoes), decontaminate feeders, perches, cages etc., and avoid close confined contact of individual birds. [8]

Vaccines have been developed from some species of the virus, such as Fowlpox , Canarypox , Pigeonpox, and Quailpox to help prevent infection in captive and domestic bird populations. [6] There is no one specific treatment used for birds who have contracted the avipoxvirus. [9] Often the avipoxvirus acts as an immune suppressant, leading to secondary bacterial infections, which are recommended for treatment. [6] Common methods include use of iodine-glycerin applications to assist in healing lesions, use of antibiotics to attempt to control secondary infections, and use of vitamin A to supplement healing of lesions. [9]

There is a demand for new vaccines, especially for endangered species. [6] The development of a single vaccine that can treat all species has been difficult to develop, since the avipoxvirus is taxon specific. [9] Currently, vaccination is not a plausible method of control for wild bird populations, where avipoxvirus is most prevalent. [6] To improve this, there are current efforts in using the avipoxviruses as vectors for recombinant vaccines in order eventually evolve them into multiple species targeted vaccines. [9]

Virology

Avipoxvirus is a genus of viruses in the family Poxviridae in the subfamily Chordopoxvirinae . Birds serve as natural hosts. There are 12 species in this genus. [11] [12]

Taxonomy

The genus contains the following species: [12]

Structure

Viruses in Avipoxvirus are enveloped. Genomes are linear, around 300kb in length. [11]

GenusStructureSymmetryCapsidGenomic arrangementGenomic segmentation
AvipoxvirusBrick-shapedEnvelopedLinearMonopartite

Life cycle

Viral replication is cytoplasmic. Entry into the host cell is achieved by attachment of the viral proteins to host glycosaminoglycans (GAGs) mediates endocytosis of the virus into the host cell. Fusion with the plasma membrane to release the core into the host cytoplasm. Early phase: early genes are transcribed in the cytoplasm by viral RNA polymerase. Early expression begins at 30 minutes post-infection. Core is completely uncoated as early expression ends, viral genome is now free in the cytoplasm. Intermediate phase: Intermediate genes are expressed, triggering genomic DNA replication at approximately 100 minutes post-infection. Late phase: Late genes are expressed from 140 minutes to 48 hours post-infection, producing all structural proteins. Assembly of progeny virions starts in cytoplasmic viral factories, producing a spherical immature particle. This virus particle matures into brick-shaped intracellular mature virion (IMV). IMV virion can be released upon cell lysis, or can acquire a second double membrane from trans-Golgi and bud as external enveloped virion (EEV) host receptors, which mediates endocytosis. Replication follows the DNA strand displacement model. DNA-templated transcription is the method of transcription. The virus exits the host cell by existing in occlusion bodies after cell death and remaining infectious until finding another host.[ citation needed ]

Birds serve as the natural host. Transmission routes are mechanical, contact, and air borne particles. [11]

GenusHost detailsTissue tropismEntry detailsRelease detailsReplication siteAssembly siteTransmission
AvipoxvirusBirdsNoneGlycosaminoglycansLysis; buddingCytoplasmCytoplasmArthropods; aerosol

Related Research Articles

<i>Poxviridae</i> Family of viruses

Poxviridae is a family of double-stranded DNA viruses. Vertebrates and arthropods serve as natural hosts. There are currently 83 species in this family, divided among 22 genera, which are divided into two subfamilies. Diseases associated with this family include smallpox.

<i>Parapoxvirus</i> Genus of viruses

Parapoxvirus is a genus of viruses, in the family Poxviridae, in the subfamily Chordopoxvirinae. Like all members of the family Poxviridae, they are oval, relatively large, double-stranded DNA viruses. Parapoxviruses have a unique spiral coat that distinguishes them from other poxviruses. Parapoxviruses infect vertebrates, including a wide selection of mammals, and humans.

<i>Baculoviridae</i> Family of viruses

Baculoviridae is a family of viruses. Arthropods, among the most studied being Lepidoptera, Hymenoptera and Diptera, serve as natural hosts. Currently, 85 species are placed in this family, assigned to four genera.

<i>Gammaretrovirus</i> Genus of viruses

Gammaretrovirus is a genus in the Retroviridae family. Example species are the murine leukemia virus and the feline leukemia virus. They cause various sarcomas, leukemias and immune deficiencies in mammals, reptiles and birds.

<span class="mw-page-title-main">Duck plague</span> Disease caused by Anatid alphaherpesvirus 1

Duck plague is a worldwide disease caused by Anatid alphaherpesvirus 1 (AnHV-1) of the family Herpesviridae that causes acute disease with high mortality rates in flocks of ducks, geese, and swans. It is spread both vertically and horizontally—through contaminated water and direct contact. Migratory waterfowl are a major factor in the spread of this disease as they are often asymptomatic carriers of disease. The incubation period is three to seven days. Birds as young as one week old can be infected. DEV is not zoonotic.

<span class="mw-page-title-main">Camelpox</span> Disease of camels caused by the Camelpox virus

Camelpox is a disease of camels caused by the camelpox virus (CMPV) of the family Poxviridae, subfamily Chordopoxvirinae, and the genus Orthopoxvirus. It causes skin lesions and a generalized infection. Approximately 25% of young camels that become infected will die from the disease, while infection in older camels is generally more mild. Although rare, the infection may spread to the hands of those that work closely with camels.

<i>Molluscum contagiosum virus</i> Species of virus

Molluscum contagiosum virus (MCV) is a species of DNA poxvirus that causes the human skin infection molluscum contagiosum. Molluscum contagiosum affects about 200,000 people a year, about 1% of all diagnosed skin diseases. Diagnosis is based on the size and shape of the skin lesions and can be confirmed with a biopsy, as the virus cannot be routinely cultured. Molluscum contagiosum virus is the only species in the genus Molluscipoxvirus. MCV is a member of the subfamily Chordopoxvirinae of family Poxviridae. Other commonly known viruses that reside in the subfamily Chordopoxvirinae are variola virus and monkeypox virus.

<span class="mw-page-title-main">Sheeppox</span> Infectious disease of sheep caused by the sheeppox virus

Sheeppox is a highly contagious disease of sheep caused by a poxvirus different from the benign orf. This virus is in the family Poxviridae and genus Capripoxvirus. Sheeppox virus (SPV) is the most severe of all the animal pox diseases and can result in some of the most significant economic consequences due to poor wool and leather quality.

Lumpy skin disease (LSD) is an infectious disease in cattle caused by a virus of the family Poxviridae, also known as Neethling virus. The disease is characterized by large fever, enlarged superficial lymph nodes and multiple nodules on the skin and mucous membranes. Infected cattle also may develop edematous swelling in their limbs and exhibit lameness. The virus has important economic implications since affected animals tend to have permanent damage to their skin, lowering the commercial value of their hide. Additionally, the disease often results in chronic debility, reduced milk production, poor growth, infertility, abortion, and sometimes death.

<span class="mw-page-title-main">Fowlpox</span> Viral disease of poultry

Fowlpox is the worldwide disease of poultry caused by viruses of the family Poxviridae and the genus Avipoxvirus. The viruses causing fowlpox are distinct from one another but antigenically similar, possible hosts including chickens, turkeys, quail, canaries, pigeons, and many other species of birds. There are two forms of the disease. The first is spread by biting insects and wound contamination and causes lesions on the comb, wattles, and beak. Birds affected by this form usually recover within a few weeks. It can also be transmitted via inhalation or ingestion of dust, or aerosols, leading to the 'diphtheritic form' of the disease, with lesions on the mucous membranes of the mouth, pharynx, larynx, and sometimes trachea. The second form is spread by inhalation of the virus and causes a diphtheritic membrane to form in the mouth, pharynx, larynx, and sometimes the trachea. The prognosis for this form is poor.

<span class="mw-page-title-main">Canarypox</span> Viral disease of birds

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.. Furthermore, the POXIMUNE® C vaccine does offer direct protection against CNPV in susceptible birds.

Turkeypox virus is a virus of the family Poxviridae and the genus Avipoxvirus that causes turkeypox. It is one of the most common diseases in the wild turkey population. Turkeypox, like all avipoxviruses, is transmitted either through skin contact or by arthropods acting as mechanical vectors.

Chordopoxvirinae is a subfamily of viruses in the family Poxviridae. Humans, vertebrates, and arthropods serve as natural hosts. Currently, 52 species are placed in this subfamily, divided among 18 genera. Diseases associated with this subfamily include smallpox.

Capripoxvirus is a genus of viruses in the subfamily Chordopoxvirinae and the family Poxviridae. Capripoxviruses are among the most serious of all animal poxviruses. All CaPV are notifiable diseases to the OIE. Sheep, goat, and cattle serve as natural hosts. These viruses cause negative economic consequences by damaging hides and wool and forcing the establishment of trade restrictions in response to an outbreak. The genus consists of three species: sheeppox virus (SPPV), goatpox virus (GTPV), and lumpy skin disease virus (LSDV). They share no serological relationship with camel pox, horse pox, or avian poxes. Capripoxviruses for sheeppox and goatpox infect only sheep and goat respectively. However, it is probable that North American relatives, the mountain goat and mountain sheep, may be susceptible to the strains but has not been experimentally proven. Lumpy skin disease virus affects primarily cattle, but studies have been shown that giraffes and impala are also susceptible to LSDV. Humans cannot be infected by Capripoxviruses.

Suipoxvirus is a genus of viruses in the family Poxviridae and subfamily Chordopoxvirinae. Swine serve as natural hosts. There is only one species in this genus: Swinepox virus. Diseases associated with this genus include asymptomatic skin disease.

Raccoonpox virus (RCN) is a double-stranded DNA virus and a member of the orthopoxviruses in the family Poxviridae and subfamily Chordopoxvirinae which consists of eight genera: Avipoxvirus, Capripoxvirus, Leporipoxvirus, Molluscipoxvirus, Orthopoxvirus, Parapoxvirus, Suipoxvirus and Yatapoxvirus Vertebrates are the natural host of Chordopoxvirinae subfamily viruses. More specifically, raccoons are the natural hosts of RCN. RCN was isolated in 1961 from the upper respiratory tissues of 2 raccoons in a group of 92 observably healthy raccoons trapped close to Aberdeen, Maryland.

<i>West Nile virus</i> Species of flavivirus causing West Nile fever

West Nile virus (WNV) is a single-stranded RNA virus that causes West Nile fever. It is a member of the family Flaviviridae, from the genus Flavivirus, which also contains the Zika virus, dengue virus, and yellow fever virus. The virus is primarily transmitted by mosquitoes, mostly species of Culex. The primary hosts of WNV are birds, so that the virus remains within a "bird–mosquito–bird" transmission cycle. The virus is genetically related to the Japanese encephalitis family of viruses.

<i>Red deerpox virus</i> Species of virus

Red deerpox virus (RDPV) is a species of virus in the genus Parapoxvirus. It has been reported in deer in New Zealand, and in wild ruminants in Italy.

Starlingpox virus is a branch of the Avipoxvirus belonging to the Chordopoxvirinae subfamily and the Poxviridae family, impacting various starling songbird species. The starling variant, Starlingpox virus has been linked to another variant, the Mynahpox virus, supporting theorizations that each variation belongs to a subclade, Sturnindaepox virus. Avian pox viruses are widespread, double-stranded, DNA genome viruses that have been found in cutaneous and diphtheritic forms in over 230 bird species.

References

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  2. ↑ "Fowlpox in Chickens and Turkeys". The Merck Veterinary Manual. 2006. Retrieved 21 June 2007.
  3. ↑ "USGS National Wildlife Health Center" (PDF). Archived from the original (PDF) on 7 May 2009. Retrieved 26 July 2015.
  4. ↑ Fischer, John R. (1999-03-22) DISEASES OF WILDLIFE: AFIP REVIEW OF GROSS MORBID ANATOMY OF ANIMALS, C.L. Davis, DVM Foundation.
  5. ↑ Michener, Harold & Michener, Josephine R. (1936). "Abnormalities in Birds". Condor. 38 (3): 102–109. doi:10.2307/1363908. JSTOR   1363908.
  6. 1 2 3 4 5 6 Gyuranecz, M, et al. 2013. "Worldwide phylogenetic relationship of avian poxviruses". Journal of Virology. 87:4938-4951.
  7. 1 2 3 4 Friend, Milton, and J. Christian. Franson. "Field Manual of Wildlife Diseases General Field Procedures and Diseases of Birds". Washington, D.C.: U.S. Dept. of the Interior, U.S. Geological Survey, 1999.
  8. 1 2 Department of Natural Resources. DNR Michigan. "Avian Pox" Accessed 24 October 2013
  9. 1 2 3 4 5 6 7 Weli, Simon and Morten Tryland. (2011). "Avipoxviruses: infection biology and their use as vaccine vectors". Virology Journal. 8:49.
  10. 1 2 United States Geological Service. 2013. National Wildlife Health Center. "Avian Pox" Accessed 25 October 2013.
  11. 1 2 3 "Viral Zone". ExPASy. Retrieved 12 June 2015.
  12. 1 2 "Virus Taxonomy: 2020 Release". International Committee on Taxonomy of Viruses (ICTV). March 2021. Retrieved 22 May 2021.
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