title: Association between the genetic similarity of the open reading frame 5 sequence of Porcine reproductive and respiratory syndrome virus and the similarity in clinical signs of Porcine reproductive and respiratory syndrome in Ontario swine herds.
abstract: A study of Ontario swine farms positive for Porcine reproductive and respiratory syndrome virus (PRRSV) tested the association between genetic similarity of the virus and similarity of clinical signs reported by the herd owner. Herds were included if a positive result of polymerase chain reaction for PRRSV at the Animal Health Laboratory at the University of Guelph, Guelph, Ontario, was found between September 2004 and August 2007. Nucleotide-sequence similarity and clinical similarity, as determined from a telephone survey, were calculated for all pairs of herds. The Mantel test indicated that clinical similarity and sequence similarity were weakly correlated for most clinical signs. The generalized additive model indicated that virus homology with 2 vaccine viruses affected the association between sequence similarity and clinical similarity. When the data for herds with vaccine-like virus were removed from the dataset there was a significant association between virus similarity and similarity of the reported presence of abortion, stillbirth, preweaning mortality, and sow/boar mortality. Ownership similarity was also found to be associated with virus similarity and with similarity of the reported presence of sows being off-feed, nursery respiratory disease, nursery mortality, finisher respiratory disease, and finisher mortality. These results indicate that clinical signs of PRRS are associated with PRRSV genotype and that herd ownership is associated with both of these.
authors.affiliation: Department of Population Medicine, University of Guelph, 50 Stone Road East, Guelph, Ontario N1G 2W1 (Rosendal, Dewey, Friendship, Young, Poljak); Department of Pathobiology, University of Guelph, 50 Stone Road East, Guelph, Ontario N1G 2W1 (Wootton), University of Guelph, Guelph, Ontario.
authors.forename: Thomas
authors.initials: T
authors.lastname: Rosendal
authors.affiliation: Department of Population Medicine, University of Guelph, 50 Stone Road East, Guelph, Ontario N1G 2W1 (Rosendal, Dewey, Friendship, Young, Poljak); Department of Pathobiology, University of Guelph, 50 Stone Road East, Guelph, Ontario N1G 2W1 (Wootton), University of Guelph, Guelph, Ontario.
authors.forename: Cate
authors.initials: C
authors.lastname: Dewey
authors.affiliation: Department of Population Medicine, University of Guelph, 50 Stone Road East, Guelph, Ontario N1G 2W1 (Rosendal, Dewey, Friendship, Young, Poljak); Department of Pathobiology, University of Guelph, 50 Stone Road East, Guelph, Ontario N1G 2W1 (Wootton), University of Guelph, Guelph, Ontario.
authors.forename: Robert
authors.initials: R
authors.lastname: Friendship
authors.affiliation: Department of Population Medicine, University of Guelph, 50 Stone Road East, Guelph, Ontario N1G 2W1 (Rosendal, Dewey, Friendship, Young, Poljak); Department of Pathobiology, University of Guelph, 50 Stone Road East, Guelph, Ontario N1G 2W1 (Wootton), University of Guelph, Guelph, Ontario.
authors.forename: Sarah
authors.initials: S
authors.lastname: Wootton
authors.affiliation: Department of Population Medicine, University of Guelph, 50 Stone Road East, Guelph, Ontario N1G 2W1 (Rosendal, Dewey, Friendship, Young, Poljak); Department of Pathobiology, University of Guelph, 50 Stone Road East, Guelph, Ontario N1G 2W1 (Wootton), University of Guelph, Guelph, Ontario.
authors.forename: Beth
authors.initials: B
authors.lastname: Young
authors.affiliation: Department of Population Medicine, University of Guelph, 50 Stone Road East, Guelph, Ontario N1G 2W1 (Rosendal, Dewey, Friendship, Young, Poljak); Department of Pathobiology, University of Guelph, 50 Stone Road East, Guelph, Ontario N1G 2W1 (Wootton), University of Guelph, Guelph, Ontario.
authors.forename: Zvonimir
authors.initials: Z
authors.lastname: Poljak
mesh_terms: D000818:Animals; D005260:Female; D008297:Male; D015999:Multivariate Analysis; D009864:Ontario; D016366:Open Reading Frames / Q000235:genetics*; D019318:Porcine Reproductive and Respiratory Syndrome / Q000473:pathology / Q000821:virology*; D019316:Porcine respiratory and reproductive syndrome virus / Q000235:genetics*; D011247:Pregnancy; D012367:RNA, Viral / Q000737:chemistry / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D017422:Sequence Analysis, DNA / Q000662:veterinary; D018709:Statistics, Nonparametric; D013552:Swine; D014765:Viral Vaccines / Q000235:genetics*
chemical_list: D012367:RNA, Viral; D014765:Viral Vaccines