CHIA-YI CHANGDeng, Ming-ChungMing-ChungDengFUN-IN WANGHSIANG-JUNG TSAIYang, Chia-HueiChia-HueiYangChang, ChiehChiehChangHuang, Yu-LiangYu-LiangHuang2022-11-112022-11-11201401660934https://www.scopus.com/inward/record.uri?eid=2-s2.0-84896461400&doi=10.1016%2fj.jviromet.2014.01.016&partnerID=40&md5=0a3758286ce204da51d55d0e56972553https://scholars.lib.ntu.edu.tw/handle/123456789/624616The 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. © 2014 Elsevier B.V.Duplicate reverse transcription real-time PCR; Porcine circovirus type 2; Porcine reproductive and respiratory syndrome virus; Surveillance[SDGs]SDG3virus antibody; virus antibody; age; animal cell; animal tissue; antibody titer; Arterivirus; article; Circovirus; controlled study; diagnostic test accuracy study; disease surveillance; duplex reverse transcription real time polymerase chain reaction; infection sensitivity; intermethod comparison; limit of detection; nonhuman; open reading frame; pig farming; porcine circovirus type 2; porcine respiratory disease complex; prevalence; priority journal; real time polymerase chain reaction; reproducibility; sensitivity and specificity; serology; swine disease; virus detection; virus load; animal; Arterivirus; blood; Circoviridae Infections; Circovirus; epidemiological monitoring; evaluation study; genetics; isolation and purification; multiplex polymerase chain reaction; porcine reproductive and respiratory syndrome; procedures; real time polymerase chain reaction; reverse transcription polymerase chain reaction; swine; Swine Diseases; veterinary; virology; Animals; Antibodies, Viral; Circoviridae Infections; Circovirus; Epidemiological Monitoring; Multiplex Polymerase Chain Reaction; Porcine Reproductive and Respiratory Syndrome; Porcine respiratory and reproductive syndrome virus; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; Sensitivity and Specificity; Swine; Swine Diseases; Viral Loadjournal article10.1016/j.jviromet.2014.01.016245607822-s2.0-84896461400