Retrospective survey and phylogenetic analysis of porcine circovirustype 3 in Jiangsu province, China, 2008 to 2017

AbstractPorcine circovirus type 3 (PCV3) is a novel porcine circovirus recently identified in pigs associated with porcine dermatitisnephropathy syndrome, reproductive failure and multi-systemic inflammation. This study aimed to identify PCV3 in clinicalsamples from pigs collected between 2008 and 2017 in Jiangsu province, China. A total of 272 pig tissue samples from141 pig farms in Jiangsu province were examined and analyzed. Forty of the 272 (14.7%) samples tested were positive forPCV3, while 28/40 (70%) of the PCV3-positive samples were co-infected with PCV2. Among them, 18, 1, 14 and 7 of thePCV3-positive samples were identified in 2013, 2014, 2015 and 2017, respectively. The complete genome sequences fromfour of the PCV3s contained 2,000 nucleotides, and shared 98.6% to 99.6% nucleotide sequence identity with the PCV3isolates available in GenBank. Our results indicate that a large outbreak of PCV3 occurred in Jiangsu province pig herds in2013, after which a fairly stable infection rate was recorded. It is imperative, therefore, to gain a better understanding of thepathogenicity of PCV3 and control its further dissemination in this region