Parvovirus
892665
215050612
2008-05-26T14:05:08Z
87.198.140.114
/* Structure */
{{Taxobox | color=violet
| name = ''Parvovirus''
| virus_group = ii
| familia = ''[[Parvoviridae]]''
| genus = '''''Parvovirus'''''
| subdivision_ranks = Species
| subdivision =
''[[Canine parvovirus]]''<br/>
''[[Chicken parvovirus]]''<br/>
''[[Feline Panleukopenia|Feline panleukopenia virus]]''<br/>
''[[Feline parvovirus]]''<br/>
''[[HB virus]]''<br/>
''[[H-1 virus]]''<br/>
''[[Kilham rat virus]]''<br/>
''[[Lapine parvovirus]]''<br/>
''[[LUIII virus]]''<br/>
''[[Mink enteritis virus]]''<br/>
''[[Minute virus of mice]]''<br/>
''[[Murine parvovirus 1]]''<br/>
''[[Porcine parvovirus]]''<br/>
''[[Raccoon parvovirus]]''<br/>
''[[RT parvovirus]]''<br/>
''[[Tumor virus X]]''
}}
'''''Parvovirus''''', commonly abbreviated to '''parvo''', is a [[genus]] of the ''[[Parvoviridae]]'' family linear, non-segmented single stranded [[DNA virus]]es with an average genome size of 5 [[base pair|kbp]]. Parvoviruses are some of the smallest viruses found in nature (hence the name, from [[Latin]] ''parvus'' meaning ''small''). Some have been found as small as 23nm.
Many types of mammalian [[species]] have a strain of parvovirus associated with them. Parvoviruses tend to be specific about the [[taxon]] of animal they will [[infect]], but this is a somewhat flexible characteristic. Thus, all strains of [[canine parvovirus]] will affect [[dog]]s, [[wolf|wolves]], and [[fox]]es, but only some of them will infect [[cat]]s.
No members of the genus Parvovirus are currently known to infect humans, but humans can be infected by viruses from three other genera from the Family Parvoviridae. These are the [[Dependoviruses]] (e.g. [[Adeno-Associated Virus]]), the [[Erythroviruses]] (e.g. [[Parvovirus B19]]) and the [[Bocaviruses]]. This virus infected many puppies in the making of the movie, [[Snow Buddies|''Snow Buddies'']].
==Structure==
The viral capsid of parvovirus is made up of 3 [[proteins]] known as VP1, VP2 and NS1 that form an icosahedral structure that is resistant to [[pH]], solvents and temperature up to 50°C.
Inside the capsid is a single stranded DNA genome. At the 5’ and 3’ ends of this genome are palindromic sequences of approximately 115 [[nucleotides]] that form hairpins and are essential for viral genome [[DNA replication|replication]].
==Parvovirus Replication==
In order to [[viral entry|enter]] host cells parvoviruses bind to a cell surface receptor. Once in the host cell the virus' DNA [[genome]] is translocated to the nucleus where transcription of the genes encoding the non-structural proteins into [[mRNA]] occurs. The mRNAs are transported out of the nucleus into the [[cytoplasm]] where the host ribosomes translate them into viral proteins. Next the CAP ([[capsid]]) proteins are transcribed and translated in the same way as the non-structural proteins. The replication of the viral genome can then occur. The process by which the parvovirus genome is replicated is poorly understood, although host [[DNA]] polymerase is needed for replication. Once the genome has replicated it is packaged inside the viral [[capsid]] within the [[cytoplasm]].
Parvoviruses do not have an envelope and so are only released when the cell undergoes [[lysis]].
In order for viral [[replication]] to take place the infected cells must be non-quiescent cells (i.e. must be actively mitotic). This is because the virus relies heavily on the host cell's replication machinery and therefore require the cell to pass through S phase. Unlike polyomaviruses, parvoviruses are unable to turn on DNA synthesis in host cells.
==Diseases==
Parvoviruses can cause [[disease]] in some [[animal]]s. Because the viruses require actively dividing cells in order to replicate, the type of tissue infected varies with the age of the animal. The [[gastrointestinal tract]] and [[lymphatic system]] can be affected at any age, leading to vomiting, diarrhea and [[immunosuppression]], but [[cerebellar hypoplasia (non-human)|cerebellar hypoplasia]] is only seen in cats that were infected in the womb or at less than two weeks of age, and disease of the [[myocardium]] is seen in puppies infected between the ages of three and eight weeks.<ref name=Fenner>{{cite book|author=Fenner, Frank J.; Gibbs, E. Paul J.; Murphy, Frederick A.; Rott, Rudolph; Studdert, Michael J.; White, David O.|title=Veterinary Virology (2nd ed.)|publisher=Academic Press, Inc|year=1993|id=ISBN 0-12-253056-X}}</ref>
''[[Canine parvovirus]]'' is a particularly deadly disease among young [[dog|puppies]], about 80% fatal, causing [[gastrointestinal tract]] damage and [[dehydration]] as well as a cardiac syndrome in very young pups. It is spread by contact with an infected dog's feces. Symptoms include lethargy, severe diarrhea, fever, vomiting, loss of appetite, and dehydration. ''[[Mouse parvovirus]] 1'', however, causes no symptoms but can contaminate [[immunology]] [[experiment]]s in [[biological]] [[research]] [[laboratory|laboratories]]. ''[[Porcine parvovirus]]'' causes a reproductive disease in [[swine]] known as [[SMEDI]], which stands for stillbirth, mummification, embryonic death, and infertility. [[Feline panleukopenia]] is common in kittens and causes fever, low [[white blood cell]] count, diarrhea, and death. Infection of the cat fetus and kittens less than two weeks old causes cerebellar hypoplasia. ''[[Mink enteritis virus]]'' is similar in effect to feline panleukopenia, except that it does not cause cerebellar hypoplasia. A different parvovirus causes [[Aleutian disease]] in [[mink]]s and other [[mustelid]]s, characterized by [[lymphadenopathy]], [[splenomegaly]], [[glomerulonephritis]], [[anemia]], and death. The most accurate [[diagnosis]] of parvovirus is by [[ELISA]]. [[Dog]]s, [[cat]]s and [[swine]] can be [[vaccination|vaccinated]] against parvovirus.
''[[Parvovirus B19]]'', which causes [[fifth disease]] in humans, is a member of the ''[[Erythrovirus]]'' genus of ''[[Parvoviridae]]'' rather than ''Parvovirus''.
==See also==
{{Viruses}}
==References==
{{Reflist}}
==Further reading==
[http://www.cats.org.uk/catcare/leaflets/665_fpv.pdf Feline Parvovirus by Cats Protection]
[[Category:Parvoviruses]]
[[Category:Virology]]
[[Category:Viruses]]
[[pt:Parvovírus]]
[[da:Parvoviridae]]
[[de:Parvoviren]]
[[fr:Parvoviridae]]
[[he:פארוו]]
[[it:Parvoviridae]]
[[ja:パルボウイルス]]
[[pl:Parwowirusy]]
[[zh:小DNA病毒科]]