Molecular Epidemiology of Porcine Circovirus Type 3 Infection in Swine Herds in China

Seven hundred thirty clinical tissue samples collected from diseased pigs in South, Middle, and North China were subjected to detect PCV3 DNA by PCR and results showed that PCV3 positive rate was 14.25%. Six PCV3 genomes were obtained and classified into 3 different clusters. The primary PCV3-postive clinical tissues were found to be lung, followed by lymph nodes, stillbirth, kidney, brain, tonsil, spleen, heart, and liver. Of these PCV3-postive samples, PCV2 and PRRSV were primary virus pathogens. The above results showed that PCV3 has widely spread in China and its potential threat to swine industry should be given full consideration.