title: The application of a duplex reverse transcription real-time PCR for the surveillance of porcine reproductive and respiratory syndrome virus and porcine circovirus type 2.
abstract: The porcine respiratory disease complex (PRDC) is the most common disease in commercial pork production worldwide. Porcine circovirus type 2 (PCV2) and porcine reproductive and respiratory syndrome virus (PRRSV), the most important agents of PRDC, usually co-infect in the same pigs. In order to survey the prevalence of PCV2 and PRRSV in pigs of various ages, a duplex reverse transcription real-time PCR (DRT-rPCR) was developed and applied in the present study. The DRT-rPCR did not cross-react with 10 swine viruses other than PCV2 and PRRSV, with detection limits of 1 TCID50/ml for PCV2 and 6.3 TCID50/ml for PRRSV. Surveillance using DRT-rPCR together with serology revealed that in the five farms studied, pigs were most susceptible to PRRSV at 6-14 weeks of age, whereas susceptibility to PCV2 varied by the management system but was mostly at 10-14 weeks of age. Cross analysis of viral loads versus antibody titers revealed that PCV2 load was affected negatively by anti-PCV2 ORF2 antibody, which constituted the most important non-infectious factor affecting the development of PMWS. These results indicated that DRT-rPCR was developed and applied successfully to the surveillance of PCV2 and PRRSV in the field.
authors.affiliation: Animal Health Research Institute, Council of Agriculture, 376 Chung-Cheng Road, Tansui, New Taipei City 25158, Taiwan.
authors.forename: Chia-Yi
authors.initials: CY
authors.lastname: Chang
authors.affiliation: Animal Health Research Institute, Council of Agriculture, 376 Chung-Cheng Road, Tansui, New Taipei City 25158, Taiwan.
authors.forename: Ming-Chung
authors.initials: MC
authors.lastname: Deng
authors.affiliation: School of Veterinary Medicine, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei 10617 Taiwan.
authors.forename: Fun-In
authors.initials: FI
authors.lastname: Wang
authors.affiliation: Animal Health Research Institute, Council of Agriculture, 376 Chung-Cheng Road, Tansui, New Taipei City 25158, Taiwan; School of Veterinary Medicine, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei 10617 Taiwan.
authors.forename: Hsiang-Jung
authors.initials: HJ
authors.lastname: Tsai
authors.affiliation: Animal Health Research Institute, Council of Agriculture, 376 Chung-Cheng Road, Tansui, New Taipei City 25158, Taiwan.
authors.forename: Chia-Huei
authors.initials: CH
authors.lastname: Yang
authors.affiliation: Animal Health Research Institute, Council of Agriculture, 376 Chung-Cheng Road, Tansui, New Taipei City 25158, Taiwan.
authors.forename: Chieh
authors.initials: C
authors.lastname: Chang
authors.affiliation: Animal Health Research Institute, Council of Agriculture, 376 Chung-Cheng Road, Tansui, New Taipei City 25158, Taiwan. Electronic address: ylhuang@mail.nvri.gov.tw.
authors.forename: Yu-Liang
authors.initials: YL
authors.lastname: Huang
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D018173:Circoviridae Infections / Q000175:diagnosis / Q000662:veterinary* / Q000821:virology; D017925:Circovirus / Q000235:genetics / Q000302:isolation & purification*; D062665:Epidemiological Monitoring; D060885:Multiplex Polymerase Chain Reaction / Q000379:methods*; D019318:Porcine Reproductive and Respiratory Syndrome / Q000175:diagnosis* / Q000821:virology; D019316:Porcine respiratory and reproductive syndrome virus / Q000235:genetics / Q000302:isolation & purification*; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D013552:Swine; D013553:Swine Diseases / Q000175:diagnosis / Q000821:virology; D019562:Viral Load
chemical_list: D000914:Antibodies, Viral
keywords: Duplicate reverse transcription real-time PCR; Porcine circovirus type 2; Porcine reproductive and respiratory syndrome virus; Surveillance