African swine fever virus 5094165 201951804 2008-03-30T02:01:49Z Alexbot 5517884 robot Adding: [[ja:アフリカ豚コレラ]] {{Taxobox | color = violet | name = ''African swine fever virus'' | image = African swine fever infected macrophage.jpg | image_caption = [[Macrophage]] cell in early stages of infection with ASFV | virus_group = i | familia = ''[[Asfarviridae]]'' | genus = ''[[Asfivirus]]'' | species = '''''African swine fever virus''''' }} '''African swine fever virus''' (ASFV) is the causative agent of African swine fever. ASFV is a large double-stranded [[DNA]] virus which replicates in the [[cytoplasm]] of infected cells and is the only member of the [[Asfarviridae]] family.<ref name=sobrino10>{{cite book |chapterurl=http://www.horizonpress.com/avir|author=Dixon et al|year=2008|chapter=African Swine Fever Virus|title=Animal Viruses: Molecular Biology|publisher=Caister Academic Press|id=[http://www.horizonpress.com/avir ISBN 978-1-904455-22-6]}}</ref> ASFV infects domestic [[pigs]], [[warthogs]] and [[bushpigs]], as well as [[soft ticks]]. The virus causes a lethal haemorraghic disease in domestic pigs, some isolates can cause death of animals within as little as a week after infection. In all of the other species the virus causes no obvious disease. ASFV is endemic to [[Sub-Saharan Africa]] and exists in the wild through a cycle of infection between ticks and wild pigs/bushpigs/warthogs. ASFV was first described after European settlers brought pigs into areas endemic with ASFV and as such is an example of an 'emerging infection'. [[Image:African swine fever ears.jpg|thumb|left|Reddening of the ears is a common sign of African swine fever in pigs.]] The clinical symptoms of ASFV are very similar to [[classical swine fever virus]] and the two diseases normally have to be distinguished by laboratory diagnosis. African swine fever was restricted to the continent that bears its name until 1957 when the disease was reported in [[Lisbon]], [[Portugal]]. A further outbreak occurred here in 1960. Subsequent to these initial introductions the disease became established in the Iberian peninsula and sporadic outbreaks occurred in [[France]], [[Belgium]] and other European countries during the 1980s. Both [[Spain]] and [[Portugal]] had managed to eradicate the disease by the mid 1990s through a slaughter policy. During the late 1970s ASFV crossed the [[Atlantic Ocean]] and outbreaks were reported in some Caribbean islands, including [[Cuba]] and the [[Dominican Republic]]. Major outbreaks of ASFV in Africa are regularly reported to the l'office international des épizooties ([[OIE]]). The most recent outbreak of ASFV outside of Africa was in [[Georgia (country)]] in April 2007. [[Image:African swine fever necropsy.jpg|thumb|The swelling around the kidneys and the muscle hemorrhages shown here are typical of pigs with African swine fever]] The appearance of ASF in the Western hemisphere at the same time as the emergence of [[AIDS]] led to some interest in whether the two were related and a report appeared in the Lancet supporting this in 1986. However, [[AIDS]] is now known to be caused by human immunodeficiency virus ([[HIV]]), no link between ASFV and AIDS has been proven or is suspected. ==Virus structure and replication== ASFV is a large double-stranded [[DNA]] [[virus]] with a [[genome]] containing at least 150 genes. The number of genes differs slightly between different isolates of the virus. ASFV has similarities to the other large DNA viruses e.g., [[poxvirus]], [[iridovirus]], [[mimivirus]]. In common with other [[viral haemorrhagic fever]]s, the main target cells for replication are those of [[monocyte]], [[macrophage]] lineage. The virus causes a [[haemorrhagic fever]] with high mortality rates in pigs, but persistently infects its natural hosts, warthogs, bushpigs and soft ticks of the [[Ornithodoros]] species with no disease signs. The virus encodes enzymes required for replication and transcription of the [[genome]], including elements of a base excision repair system, structural proteins and many proteins that are not essential for replication in cells but have roles in virus survival and transmission in its hosts. Virus replication takes place in perinuclear factory areas. Assembly of the icosahedral [[capsid]] occurs on modified membranes from the [[endoplasmic reticulum]]. Products from proteolytically processed polyproteins form the core shell between the internal membrane and the [[nucleoprotein]] core. An additional outer membrane is gained as particles bud from the [[plasma membrane]]. The virus encodes proteins that inhibit signalling pathways in infected macrophages and thus modulate transcriptional activation of [[immune response]] genes. In addition the virus encodes proteins which inhibit [[apoptosis]] of infected cells to facilitate production of progeny virions. Viral membrane proteins with similarity to cellular [[adhesion protein]]s modulate interaction of virus-infected cells and extracellular virions with host components.<ref name=sobrino10>{{cite book |chapterurl=http://www.horizonpress.com/avir|author=Dixon et al|year=2008|chapter=African Swine Fever Virus|title=Animal Viruses: Molecular Biology|publisher=Caister Academic Press|id=[http://www.horizonpress.com/avir ISBN 978-1-904455-22-6]}}</ref> ==See also== *[[Animal virology|Animal viruses]] *[[Virology]] ==References== {{Reflist}} ==External links== * OIE Animal Disease Data: http://www.oie.int/eng/maladies/fiches/a_A120.htm * Institute for Animal Health Factfile: http://www.iah.ac.uk/disease/AfSwFe.shtml * Department of Environment, Food and Rural Affairs Disease Factsheet: http://www.defra.gov.uk/animalh/diseases/notifiable/asf/index.htm *[http://www.horizonpress.com/gateway/animal-viruses.html Animal viruses] [[Category:Swine diseases]] [[Category:Viruses]] [[Category:Animal virology]] {{virus-stub}} {{veterinary-med-stub}} [[ka:აფრიკული ღორის ცხელება]] [[ja:アフリカ豚コレラ]]