Molecular epidemiological investigation of porcine circovirus type 3 in South China

Porcine circovirus 3 （PCV3） is a novel porcine circovirus. However, the distribution and genetic characteristics of emerging PCV3 in south China remains unclear. In this study, we used real-time PCR method to detect PCV3 in clinical samples from south China, then the complete genome sequence of PCV3 was amplified from positive samples and analysis with conference strains. The results showed that the positive rate of PCV3 in individual samples and at the farm level was 46.3% and 69.2%, respectively. The south China PCV3 shared 97.4%-99.8% and 96.6 %-99.8% nucleotide identity in the complete genome and ORF2, respectively. These data suggested that PCV3 is widely distributed in pig populations of South China.