Porcine noroviruses and sapoviruses on Korean swine farms

Porcine noroviruses (NoVs) and sapoviruses (SaVs), which belong to the family Caliciviridae, have been considered potential zoonotic agents for human infection, and several cases have been reported in Asian countries. In this study, a total of 537 porcine fecal samples collected from 64 swine farms in Korea were tested. Among 537 samples, porcine NoVs were detected by semi-nested RT-PCR in ten samples (1.9%), and porcine SaVs were detected by RT-PCR in 60 samples (11.2%), showing their circulation in Korea. The porcine NoVs were genetically related to strains of genotypes 11 and 18, of genogroup II (GII) of the genus Norovirus. The porcine SaV strains were genetically related to the porcine enteric calicivirus Cowden strain and to the previously identified Korean porcine strains in genogroup III (GIII) of the genus Sapovirus. In no case was co-infection with both NoV and SaV observed in one pig. This is the first report describing porcine NoVs identified in Korea.