title: Experimental reproduction of postweaning multisystemic wasting syndrome (PMWS) in pigs in Sweden and Denmark with a Swedish isolate of porcine circovirus type 2.
abstract: An experimental model using 3-day-old snatch-farrowed colostrum-deprived piglets co-infected with porcine circovirus type 2 (PCV2) and porcine parvovirus (PPV) is at present one of the best methods to study factors affecting development of postweaning multisystemic wasting syndrome (PMWS). A Swedish isolate of PCV2 (S-PCV2) retrieved in 1993 from a healthy pig has been used in this model to reproduce PMWS in pigs from Northern Ireland. This virus has been present in the Swedish pig population for at least a decade without causing any known PMWS disease problems, despite its potential pathogenicity. The reasons for this are unknown, but could be related to genetics, absence of triggers for PCV2 upregulation (infectious agent and/or management forms) within Swedish pig husbandry. In order to confirm the pathogenicity of S-PCV2, Swedish and Danish pigs were experimentally infected with this isolate according to the established model. Swedish pigs were also infected with a reference isolate of PCV2 (PCV2-1010) to compare the severity of disease caused by the two isolates in Swedish pigs. Both Danish and Swedish pigs developed PMWS after the experimental infection with S-PCV2. Antibodies to PCV2 developed later and reached lower levels in serum from pigs infected with S-PCV2 than in pigs inoculated with PCV2-1010. In general, pigs infected with S-PCV2 showed more severe clinical signs of disease than pigs infected with PCV2-1010, but pigs from all PCV2-inoculated groups displayed gross and histological lesions consistent with PMWS. All pigs inoculated with PPV, alone or in combination with PCV2, displayed interleukin-10 responses in serum while only pigs infected with PPV in combination with PCV2 showed interferon-alpha in serum on repeated occasions. Thus, the pathogenicity of S-PCV2 was confirmed and a role for cytokines in the etiology of PMWS was indicated.
authors.affiliation: Department of Molecular Biosciences, Section of Veterinary Immunology and Virology, Swedish University of Agricultural Sciences, Biomedical Centre, PO Box 588, SE-751 23 Uppsala, Sweden. frida.hasslung@vmm.slu.se
authors.forename: F
authors.initials: F
authors.lastname: Hasslung
authors.forename: P
authors.initials: P
authors.lastname: Wallgren
authors.forename: A-S
authors.initials: AS
authors.lastname: Ladekjaer-Hansen
authors.forename: A
authors.initials: A
authors.lastname: Bøtner
authors.forename: J
authors.initials: J
authors.lastname: Nielsen
authors.forename: E
authors.initials: E
authors.lastname: Wattrang
authors.forename: G M
authors.initials: GM
authors.lastname: Allan
authors.forename: F
authors.initials: F
authors.lastname: McNeilly
authors.forename: J
authors.initials: J
authors.lastname: Ellis
authors.forename: S
authors.initials: S
authors.lastname: Timmusk
authors.forename: K
authors.initials: K
authors.lastname: Belák
authors.forename: T
authors.initials: T
authors.lastname: Segall
authors.forename: L
authors.initials: L
authors.lastname: Melin
authors.forename: M
authors.initials: M
authors.lastname: Berg
authors.forename: C
authors.initials: C
authors.lastname: Fossum
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D000956:Antigens, Viral / Q000032:analysis; D001831:Body Temperature; D001835:Body Weight; D018173:Circoviridae Infections / Q000276:immunology / Q000662:veterinary* / Q000821:virology; D017925:Circovirus / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification* / Q000472:pathogenicity; D004279:DNA, Viral / Q000737:chemistry / Q000235:genetics; D003718:Denmark; D006651:Histocytochemistry / Q000662:veterinary; D016898:Interferon-alpha / Q000097:blood; D016753:Interleukin-10 / Q000097:blood; D010322:Parvoviridae Infections / Q000276:immunology / Q000662:veterinary / Q000821:virology; D028323:Parvovirus, Porcine / Q000276:immunology; D016133:Polymerase Chain Reaction / Q000662:veterinary; D013548:Sweden; D013552:Swine; D013553:Swine Diseases / Q000276:immunology / Q000821:virology*; D014774:Virulence; D019282:Wasting Syndrome / Q000276:immunology / Q000662:veterinary* / Q000821:virology
chemical_list: D000914:Antibodies, Viral; D000956:Antigens, Viral; D004279:DNA, Viral; D016898:Interferon-alpha; D016753:Interleukin-10
references.citation: Vet Microbiol. 2004 Feb 4;98(2):165-8
references.pmid: 14741129
references.citation: J Vet Diagn Invest. 1998 Jan;10(1):3-10
references.pmid: 9526853
references.citation: J Vet Med B Infect Dis Vet Public Health. 2000 Mar;47(2):81-94
references.pmid: 10763376
references.citation: Prev Vet Med. 2003 Nov 12;61(3):209-25
references.pmid: 14554144
references.citation: Vet Microbiol. 2004 Mar 5;98(3-4):209-20
references.pmid: 15036529
references.citation: Immunol Lett. 2004 May 15;93(2-3):97-108
references.pmid: 15158604
references.citation: Scand J Immunol. 1995 Feb;41(2):121-9
references.pmid: 7863258
references.citation: Vet Microbiol. 2002 Oct 22;89(2-3):97-114
references.pmid: 12243888
references.citation: J Vet Diagn Invest. 2000 Sep;12(5):400-5
references.pmid: 11021425
references.citation: Vet Microbiol. 2004 Feb 4;98(2):131-5
references.pmid: 14741125
references.citation: J Vet Med B Infect Dis Vet Public Health. 2003 Mar;50(2):99-101
references.pmid: 12675903
references.citation: Vet Microbiol. 1997 Jan;54(1):1-16
references.pmid: 9050166
references.citation: Vet Immunol Immunopathol. 2004 May;99(1-2):63-71
references.pmid: 15113655
references.citation: Vet Microbiol. 2004 Feb 4;98(2):159-63
references.pmid: 14741128
references.citation: Vet Pathol. 2000 May;37(3):254-63
references.pmid: 10810990
references.citation: Can Vet J. 1998 Jan;39(1):44-51
references.pmid: 9442952
references.citation: Arch Virol. 2001;146(5):909-22
references.pmid: 11448029
references.citation: Arch Virol. 2000;145(11):2421-9
references.pmid: 11205128
references.citation: J Gen Virol. 2003 Dec;84(Pt 12):3453-3457
references.pmid: 14645926
references.citation: J Gen Virol. 2004 Feb;85(Pt 2):293-304
references.pmid: 14769887
references.citation: J Gen Virol. 2003 Aug;84(Pt 8):2117-2125
references.pmid: 12867643
references.citation: J Comp Pathol. 2003 Aug-Oct;129(2-3):205-12
references.pmid: 12921727
references.citation: Viral Immunol. 2002;15(4):549-56
references.pmid: 12513926
references.citation: J Gen Virol. 1998 Sep;79 ( Pt 9):2171-9
references.pmid: 9747726
references.citation: Vet Microbiol. 2002 May 24;86(4):281-93
references.pmid: 11955778
references.citation: J Vet Diagn Invest. 2002 Nov;14(6):449-56
references.pmid: 12423025
references.citation: Can J Vet Res. 2003 May;67(2):114-20
references.pmid: 12760476
references.citation: J Vet Diagn Invest. 2003 Nov;15(6):553-60
references.pmid: 14667018
references.citation: J Gen Virol. 2003 Oct;84(Pt 10):2755-2760
references.pmid: 13679610
references.citation: J Comp Pathol. 1999 Jul;121(1):1-11
references.pmid: 10373289
references.citation: J Vet Med B Infect Dis Vet Public Health. 2000 Nov;47(9):663-75
references.pmid: 11244867