Porcine circovirus

Taxobox
virus_group = ii
familia = "Circoviridae"
genus = Circovirus

Porcine Circovirus (PCV) is a single stranded DNA virus (class II), that is non-enveloped with an un-segmented circular genome. The viral capsid is icosahedral and approximately 17nm in diameter. PCV is a member of the virus family Circoviridae.

PCV are the smallest viruses replicating autonomously in eukaryotic cells.cite book |chapterurl=http://www.horizonpress.com/avir|author=Mankertz P|year=2008|chapter=Molecular Biology of Porcine Circoviruses|title=Animal Viruses: Molecular Biology|publisher=Caister Academic Press|id= [http://www.horizonpress.com/avir ISBN 978-1-904455-22-6] ] They replicate in the nucleus of infected cells, utilising the host polymerase for genome amplification.

There are 2 strains: Type 1 PCV and Type 2 PCV

Type 1 PCV (first identified in 1974) readily infects but is not known to cause disease in swine; it is the type 2 that has caused problems in recent years with the increasing occurrence of postweaning multisystemic wasting syndrome (PMWS) which over time results in significant depletion of lymphocytes; post mortem of diseased animals reveals enlarged lymph nodes and abnormal lung tissue.

It is still unclear whether type 2 PCV (first isolated in 1997) actually causes PMWS, as infection with the virus alone causes no clinical signs, it appears to work synergistically with parvovirus, perhaps with parvovirus activating a latent form of circovirus or weakening the immune system enough for PCV to take hold. PCV1 and PCV2 show a high degree of sequence homology and a similar genomic organisation; nevertheless, the basis of the distinct pathogenicity has not yet been unravelled.cite book |chapterurl=http://www.horizonpress.com/avir|author=Mankertz P|year=2008|chapter=Molecular Biology of Porcine Circoviruses|title=Animal Viruses: Molecular Biology|publisher=Caister Academic Press|id= [http://www.horizonpress.com/avir ISBN 978-1-904455-22-6] ]

Effective vaccination is now available. Fort Dodge Animal Health (Wyeth) launched the first USDA approved vaccine in 2006.

ee also

*Animal viruses

References

External links

* [http://www.pcvd.org/ The Control of Porcine Circovirus Diseases (PCVDs): Towards Improved Food Quality and Safety]
* [http://www.addl.purdue.edu/newsletters/1998/spring/ccad.shtml Animal Disease Diagnostic Laboratory]
* [http://www.cvm.uiuc.edu/ope/enotes/showarticle.cfm?id=53 Porcine Circovirus Type 2]
* [http://www.porkscience.org/documents/circovirus.pdf Swine health fact sheet]
* [http://www.abetterchoice.ca/Creative/Assets/PDF/Porc_Quebec_Economics_ENGLISH_OCT_2005.pdf The Ecomonics of PMWS - Porc Quebec Magazine Article]
* [http://www.horizonpress.com/gateway/animal-viruses.html Animal viruses]
* [http://www.stopcircovirus.com/ Stopcircovirus.com]