Squirrelpox virus

Last updated

Squirrelpox virus
'Belinda' (14447145648).jpg
This red squirrel's mouth is showing the first signs of potential Squirrelpox virus infection
Virus classification OOjs UI icon edit-ltr.svg
(unranked): Virus
Realm: Varidnaviria
Kingdom: Bamfordvirae
Phylum: Nucleocytoviricota
Class: Pokkesviricetes
Order: Chitovirales
Family: Poxviridae
Genus: unassigned
Species:
Squirrelpox virus
Synonyms [1]
  • Squirrel parapoxvirus
  • Squirrel poxvirus

Squirrelpox virus (SQPV) is a virus that causes the fatal disease squirrelpox in United Kingdom and Republic of Ireland red squirrels. The virus is often carried by grey squirrels from North America, [2] which rarely die from the disease. Elsewhere in the Red Squirrel's European range, either the grey squirrel does not occur or it lacks the poxvirus.

Contents

Overview

Grey squirrels very rarely die from this disease as their population has developed immunity having been exposed to the virus for many years; however, they are still carriers of the infection and can spread the disease to red squirrels. In sharp contrast, there are no known red squirrels that have developed immunity to the disease, and the mortality rate for untreated infected squirrels in the wild appears to be 100%, [3] most dying within 4–5 days of being infected. [4] There has been some more recent anecdotal evidence on resistance to Squirrel pox in the red population including the finding of a healthy red squirrel with antibodies to the virus in Cumbria. [5] However the mortality rate is still considered severe, and certainly capable of local extinction of red squirrels in areas that succumb to the disease.

Taxonomy

The ICTV abbreviation for Squirrelpox virus is SQPV. [1] The classification of the virus is still under debate, and the recent studies have suggested that it should be grouped into a clade of its own rather than Parapoxvirus . [6]

Transmission

The virus can spread through contact with the infected lesions or contaminated crusts, and can also be carried by mosquitoes. [7] Most poxviruses are highly resistant to drying, which allows crusts to remain infectious for long periods of time. It is believed that the virus can be transferred by contaminated feeders, which is why red squirrel preservation organizations often recommend that feeders are disinfected daily. Many poxviruses are potentially zoonotic, and other poxviral infections have been reported in man. [8] However, no cases of transmission to humans are known. [7]

Symptoms

UK squirrelpox virus is an entirely different virus to that which causes skin fibromas (tumours) in American grey squirrels. UK grey squirrels carry the virus but are unaffected by it whereas in red squirrels, the virus causes skin ulcers, lesions, and scabs. It can also cause swelling and discharge (from the lesions/scabs) near the eyes, mouth, feet, and genitalia. Additionally, squirrels that fall victim to the disease often become increasingly lethargic as it progresses. Infected animals are said to resemble rabbits with myxomatosis, in that they are sometimes found shivering and lethargic.

Origins

SQPV is found in the eastern part of North America from Ontario in the north to North Carolina in the south. [7] The origins of squirrelpox virus in the UK are mostly unknown. The first confirmed incident was in East Anglia in the 1980s. It has since spread to Lancashire (confirmed in 1995–1996), Cumbria (spring 1998), Durham (1999), and Northumberland (1999). The squirrelpox virus is regarded as a significant factor in the decline of red squirrel populations in the UK.

Although the squirrelpox virus has only been recorded once in Scotland, it may be more prevalent due to lack of thorough testing.

It is thought to be similar to a case of disease seen in East Anglian red squirrels at the turn of the 20th century.

Long-term effects

Although red squirrels were once prevalent throughout the British Isles, there are now only about 140,000. [9] Most of these are in Scotland. The decline of red squirrels is blamed mostly on disease, the loss of woodlands, and competition by grey squirrels. There are over 2.5 million grey squirrels in the British Isles. Red squirrels' survival chances in conifer woods are much higher than in deciduous woods.

Vaccine Development

In early 2023, over 11,000 people signed a petition to the Welsh Senedd calling for research into a vaccine to be restarted. [10] Promising virus attenuation studies had ended a decade earlier in 2013 after funding ran out. [11]

Related Research Articles

<span class="mw-page-title-main">Cowpox</span> Disease of humans and animals

Cowpox is an infectious disease caused by the cowpox virus (CPXV). It presents with large blisters in the skin, a fever and swollen glands, historically typically following contact with an infected cow, though in the last several decades more often from infected cats. The hands and face are most frequently affected and the spots are generally very painful.

<span class="mw-page-title-main">Myxomatosis</span> Rabbit disease caused by Myxoma virus

Myxomatosis is a disease caused by Myxoma virus, a poxvirus in the genus Leporipoxvirus. The natural hosts are tapeti in South and Central America, and brush rabbits in North America. The myxoma virus causes only a mild disease in these species, but causes a severe and usually fatal disease in European rabbits.

<span class="mw-page-title-main">Orf (disease)</span> Human disease

Orf is a farmyard pox, a type of zoonosis. It causes small pustules in the skin of primarily sheep and goats, but can also occur on the hands of humans. A pale halo forms around a red centre. It may persist for several weeks before crusting and then either resolves or leaves a hard lump. There is usually only one lesion, but there may be many, and they are not painful. Sometimes there are swollen lymph glands.

<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.

<span class="mw-page-title-main">Bovine papular stomatitis</span> Species of virus

Bovine papular stomatitis is a farmyard pox caused by Bovine papular stomatitis virus (BPSV), which can spread from infected cattle to cause disease in milkers, farmers and veterinarians. Generally there is usually one or a few skin lesions typically on the hands or forearm. The disease is generally mild.

<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.

<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. The second is contracted by inhalation or ingestion of the virus via dust or aerosols, leading to the 'diphtheritic form' of the disease, in which diphtheritic membranes 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.

Avipoxvirus 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. 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. There is no evidence that this virus can infect humans.

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.

<span class="mw-page-title-main">Smallpox</span> Eradicated viral disease

Smallpox was an infectious disease caused by variola virus, which belongs to the genus Orthopoxvirus. The last naturally occurring case was diagnosed in October 1977, and the World Health Organization (WHO) certified the global eradication of the disease in 1980, making smallpox the only human disease to have been eradicated to date.

Variola caprina is a contagious viral disease caused by Goatpox virus, a pox virus that affects goats. The virus usually spreads via the respiratory system, and sometimes spreads through abraded skin. It is most likely to occur in crowded stock. Sources of the virus include cutaneous lesions, saliva, nasal secretions and faeces. There are two types of the disease: the papulo-vesicular form and the nodular form. The incubation period is usually 8–13 days, but it may be as short as four days.

<span class="mw-page-title-main">Pigeon pox</span> Viral disease of pigeons

Pigeon pox is a viral disease to which only pigeons are susceptible. It is characterized by pox scabs, which most frequently form on the featherless parts of the bird. The disease is caused by the Pigeon pox virus. It can be transmitted by droplet infection from one animal to another, or more commonly through infected insects or the digestion of contaminated food or water.

Quokkapox virus (QPV), also known as quokka poxvirus, marsupial papillomavirus, or marsupialpox virus, is a dsDNA virus that causes quokkapox. It is unclear whether this virus is its own species or a member of another species. It primarily infects the quokka, which is one of only four macropodid marsupials to get pox lesions. The lesions can mainly be seen on the tail, and can be up to 5 centimetres (2.0 in) in diameter. The biological behavior of this virus has yet to be identified; these lesions seem to be species-specific. The papilloma- like lesion in humans showcase many differences from the marsupial papillomata.

Chordopoxvirinae is a subfamily of viruses in the family Poxviridae. 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.

<i>Monkeypox virus</i> Species of double-stranded DNA virus

The monkeypox virus, is a species of double-stranded DNA virus that causes mpox disease in humans and other mammals. The monkeypox virus is a zoonotic virus belonging to the orthopoxvirus genus, making it closely related to the variola, cowpox, and vaccinia viruses. MPV is oval-shaped with a lipoprotein outer membrane. The genome is approximately 190 kb.

Pseudocowpox is a disease caused by the Paravaccinia virus or Pseudocowpox virus, a virus of the family Poxviridae and the genus Parapoxvirus. Humans can contract the virus from contact with livestock infected with Bovine papular stomatitis and the disease is common among ranchers, milkers, and veterinarians. Infection in humans will present with fever, fatigue, and lesion on the skin.

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

  1. 1 2 "ICTV Taxonomy history: Squirrelpox virus". International Committee on Taxonomy of Viruses (ICTV). Retrieved 28 January 2019.
  2. "Wildlife Disease Association -". pinnacle-secure.allenpress.com. Retrieved 28 January 2019.
  3. "U.K. Red Squirrel Drop: Are Gray Squirrels to Blame?". nationalgeographic.com. Archived from the original on 7 May 2003. Retrieved 5 June 2015.
  4. "Archived copy" (PDF). Archived from the original (PDF) on 22 February 2006. Retrieved 18 March 2005.{{cite web}}: CS1 maint: archived copy as title (link)
  5. Sainsbury, Anthony W.; Nettleton, Peter; Gilray, Janice; Gurnell, John (2000). "Grey squirrels have high seroprevalence to a parapoxvirus associated with deaths in red squirrels". Animal Conservation. 3 (3): 229–233. Bibcode:2000AnCon...3..229S. doi:10.1111/j.1469-1795.2000.tb00107.x. S2CID   84648904.
  6. McInnes, CJ; Wood, AR; Thomas, K; Sainsbury, AW; Gurnell, J; Dein, J; Nettleton, PF (2006). "Genomic characterization of a novel poxvirus contributing to the decline of the red squirrel (Sciurus vulgaris) in the UK". Journal of General Virology. 87 (8): 2115–2125. doi: 10.1099/vir.0.81966-0 . PMID   16847106.
  7. 1 2 3 Squirrel pox Michigan State Department of Natural Resources
  8. Kaaden O-R: Infektionen und Krankheiten durch Pockenviren. In: Medizinische Mikrobiologie, Infektions- und Seuchenlehre, ed. Mayer A, 7ed., pp 158–174, Enke Verlag, Stuttgart, Germany 2002 (from Archived 13 April 2005 at the Wayback Machine )
  9. Department of the Official Report (Hansard), House of Lords, Westminster (1 February 2006). "Lords Hansard text for 1 Feb 2006 (60201w03)". Publications.parliament.uk. Retrieved 22 November 2013.{{cite web}}: CS1 maint: multiple names: authors list (link)
  10. "Red squirrels: Vaccine call to save animal from killer pox". BBC News. 3 April 2023. Retrieved 22 March 2024.
  11. Shuttleworth, Craig (21 December 2022). "Squirrelpox outbreak detected in north Wales – without a vaccine, the disease will keep decimating red squirrels". The Conversation. Retrieved 22 March 2024.