Molecular epidemiological surveillance and complete genome analysis of porcine circoviruses in wild boars (Sus scrofa) in Gyeongnam Province, South Korea.

Importance: Porcine circovirus (PCV) is a global concern due to its financial impact on the pig industry. Molecular epidemiology of PCV2 and PCV3 in wild boars is essential for understanding viral dispersal and evolution in the wild boar population.

Objective: This study aimed to assess the prevalence and genotypic traits of PCV2 and PCV3 in wild boars in the Gyeongnam region.

Methods: Serum samples from wild boars in Gyeongnam Province were screened for PCV2 and PCV3, and polymerase chain reaction-positive samples were further subjected to genotyping and whole-genome sequencing of PCV2 and PCV3.

Results: Thirty-eight samples tested positive for PCV2, 7 for PCV3, and 2 for PCV2 and PCV3 (coinfection). PCV2d and PCV3b are the dominant genotypes, causing PCV2 and PCV3 coinfections. Wild boar PCV2 and PCV3 viruses closely resemble their corresponding genotypic strains circulating in South Korea.

Conclusions and relevance: The circulation of PCV2 and/or PCV3 in wild species poses an additional challenge for commercial pig farming due to potential contact with infected wild boars. Our findings highlight the necessity for active monitoring and surveillance of wild boars and the enforcement of stringent biosecurity measures on commercial swine farms to mitigate the risk of PCV spillover to the domestic pig population.