title: Emergence of a novel mutant PCV2b variant associated with clinical PCVAD in two vaccinated pig farms in the U.S. concurrently infected with PPV2.
abstract: Porcine circovirus (PCV) type 2b (PCV2b) emerged in North America in 2005-2006. During May of 2012, PCVAD occurred in 10-18-week-old pigs in two farms within a production system that routinely vaccinated against PCV2. Both farms received replacement gilts from the same multiplier. A mutant PCV2b strain not previously present in North America was identified. The strain was found to be 99.9% identical to a recently described mutant PCV2 isolate reported in China in 2010 and thought to be more virulent than classical PCV2a or PCV2b strains. It is possible that the current PCV2a-based commercial vaccines are not fully protective against this new strain. In addition, emerging porcine parvovirus type 2 (PPV2) was detected in 55% of the serum samples (73/132), perhaps implying that PPV2 could be a cofactor in cases of PCVAD.
authors.affiliation: Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, USA. tanjaopr@iastate.edu
authors.forename: Tanja
authors.initials: T
authors.lastname: Opriessnig
authors.forename: Chao-Ting
authors.initials: CT
authors.lastname: Xiao
authors.forename: Priscilla F
authors.initials: PF
authors.lastname: Gerber
authors.forename: Patrick G
authors.initials: PG
authors.lastname: Halbur
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D001483:Base Sequence; D002681:China; D018173:Circoviridae Infections / Q000150:complications / Q000276:immunology / Q000662:veterinary* / Q000821:virology; D017925:Circovirus / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification / Q000472:pathogenicity; D005814:Genes, Viral / Q000235:genetics; D008969:Molecular Sequence Data; D010322:Parvoviridae Infections / Q000150:complications / Q000662:veterinary* / Q000821:virology; D028323:Parvovirus, Porcine / Q000235:genetics; D016415:Sequence Alignment; D013552:Swine; D013553:Swine Diseases / Q000276:immunology / Q000517:prevention & control / Q000821:virology*; D014481:United States; D014765:Viral Vaccines / Q000592:standards
chemical_list: D000914:Antibodies, Viral; D014765:Viral Vaccines