title: Comparison of viremia of type II porcine reproductive and respiratory syndrome virus in naturally infected pigs by zip nucleic acid probe-based real-time PCR.
abstract: BACKGROUND
  Porcine reproductive and respiratory syndrome virus (PRRSV) is a RNA virus with high genetic variation. This virus causes significant economic losses in most pig-producing countries. The clinical presentation of PRRSV ranges from asymptomatic to devastating. In this study, we developed a sensitive and specific zip nucleic acid probe-based real-time PCR assay to evaluate the viremia of natural PRRSV-infected pigs in Taiwan. Serum samples were collected from 577 pigs aged 5-12 weeks. These include 444 clinically healthy pigs and 133 symptomatic pigs were confirmed to have porcine respiratory disease complex (PRDC).
  
  
  RESULTS
  Viremia was quantified in 79 of the 444 (17.8%) clinically healthy pigs and in 112 of the 133 (84.2%) PRDC cases. Viremias were significantly more common in pigs with PRDC compared with the clinically healthy pigs (P <0.0001). These results suggest that a high viral load is a major feature of PRRSV-affected pigs.
  
  
  CONCLUSIONS
  ZNA probe-based real-time PCR can be a useful tool to diagnose symptomatic and asymptomatic PRRSV-infected pigs. The presence of this marker in a sample of animals with high PRRSV loads (>10(4.2) PRRSV genomes/μl of serum) seems to indicate that it correlates with the presence of PRDC in pigs.
authors.affiliation: Department of Veterinary Medicine, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan, Republic of China. mtchiou@mail.npust.edu.tw.
authors.forename: Chao-Nan
authors.initials: CN
authors.lastname: Lin
authors.forename: Wei-Hao
authors.initials: WH
authors.lastname: Lin
authors.forename: Li-Ning
authors.initials: LN
authors.lastname: Hung
authors.forename: Sheng-Yuan
authors.initials: SY
authors.lastname: Wang
authors.forename: Ming-Tang
authors.initials: MT
authors.lastname: Chiou
mesh_terms: D000818:Animals; D009696:Nucleic Acids / Q000145:classification* / Q000302:isolation & purification; D019318:Porcine Reproductive and Respiratory Syndrome / Q000097:blood / Q000175:diagnosis / Q000821:virology*; D019316:Porcine respiratory and reproductive syndrome virus / Q000145:classification*; D060888:Real-Time Polymerase Chain Reaction / Q000662:veterinary*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013552:Swine; D019562:Viral Load; D014766:Viremia / Q000662:veterinary* / Q000821:virology
chemical_list: D009696:Nucleic Acids
references.citation: Virol J. 2011 Feb 19;8:73
references.pmid: 21333014
references.citation: J Virol Methods. 2004 Dec 15;122(2):171-8
references.pmid: 15542141
references.citation: J Virol Methods. 2005 Mar;124(1-2):11-9
references.pmid: 15664045
references.citation: J Virol Methods. 2008 Aug;151(2):194-9
references.pmid: 18582953
references.citation: Curr Opin Virol. 2012 Jun;2(3):256-63
references.pmid: 22709514
references.citation: Arch Virol. 2013 Mar;158(3):717-21
references.pmid: 23160706
references.citation: Vet Microbiol. 2011 Sep 28;152(3-4):235-46
references.pmid: 21641124
references.citation: Appl Environ Microbiol. 2006 Jul;72(7):4811-8
references.pmid: 16820475
references.citation: Asian Pac J Cancer Prev. 2012;13(8):3657-61
references.pmid: 23098450
references.citation: Arch Virol. 2009;154(10):1589-97
references.pmid: 19672556
references.citation: Res Vet Sci. 2008 Aug;85(1):184-93
references.pmid: 18054369
references.citation: J Vet Diagn Invest. 2005 Mar;17(2):165-70
references.pmid: 15825498
references.citation: Virol J. 2010 May 10;7:90
references.pmid: 20459705
references.citation: Vet Microbiol. 2010 Dec 15;146(3-4):226-37
references.pmid: 20510553
references.citation: Lett Appl Microbiol. 2008 Jan;46(1):55-60
references.pmid: 17944835
references.citation: Virus Res. 2010 Dec;154(1-2):7-17
references.pmid: 20837072
references.citation: Clin Vaccine Immunol. 2009 Dec;16(12):1822-8
references.pmid: 19828768
references.citation: Vet Microbiol. 2009 Jul 2;138(1-2):150-5
references.pmid: 19349127
references.citation: J Virol Methods. 2009 Nov;161(2):192-8
references.pmid: 19539654
references.citation: Vet Microbiol. 2005 Dec 20;111(3-4):223-9
references.pmid: 16289542
references.citation: J Virol Methods. 2007 Apr;141(1):102-6
references.pmid: 17188757
references.citation: J Virol Methods. 2005 Jun;126(1-2):21-30
references.pmid: 15847915
references.citation: Vet Microbiol. 2009 May 12;136(3-4):233-9
references.pmid: 19117699
references.citation: J Virol Methods. 2009 Jun;158(1-2):41-5
references.pmid: 19200443
references.citation: Virus Res. 2009 Sep;144(1-2):136-44
references.pmid: 19406176
references.citation: Nucleic Acids Res. 2010 Apr;38(7):e95
references.pmid: 20071749
references.citation: J Virol Methods. 2008 Apr;149(1):49-55
references.pmid: 18313768
references.citation: Nucleic Acids Res. 2009 Oct;37(19):e130
references.pmid: 19696078
references.citation: Virus Res. 2009 Oct;145(1):97-105
references.pmid: 19559739
references.citation: Nucleic Acids Res. 2002 Mar 15;30(6):1292-305
references.pmid: 11884626
references.citation: J Virol Methods. 2004 Apr;117(1):75-80
references.pmid: 15019262
references.citation: Vet Microbiol. 2005 Jan 5;105(1):19-28
references.pmid: 15607080
references.citation: J Clin Microbiol. 2004 Oct;42(10):4453-61
references.pmid: 15472293
references.citation: Anal Biochem. 1987 Apr;162(1):156-9
references.pmid: 2440339