Monitoring of foodborne viruses in pre- and post-washed root vegetables in the Republic of Korea

Fresh root vegetables are one of the main causes of viral foodborne diseases; however, the associated risk has not been fully considered. Therefore, the prevalence of five foodborne viruses including norovirus (NoV), hepatitis A virus (HAV), rotavirus (RotaV), adenovirus (AdV), and astrovirus (AstroV) in pre- and post-washed root vegetables (potato, carrot, sweet potato, and radish) were investigated by RT-qPCR or qPCR, nested RT-PCR, and sequencing. AdV and NoV GII were only detected in pre-washed samples. NoV GII was found in 1% and 2% of the potatoes and carrots, respectively and AdV in 4% and 10% of the potatoes and radishes, respectively. HAV was detected in 5.8% and 1.3% of the pre-and post-washed sweet potatoes, respectively and in 8% and 2% of the post-washed carrots and radishes, respectively. NoV GI and AstroV was not detected in any of the root vegetables. Sequencing and phylogenetic analysis revealed that the genotypes of AdV, NoV, and HAV were belonged to human AdV 41, NoV GII.3, and HAV IA and IB, respectively. This molecular surveillance study clearly demonstrated that human pathogenic viruses are found in root vegetables, and it is possible that they may serve as a potential reservoir for such viruses. Therefore, further research is necessary to confirm this hypothesis. Nevertheless, washing produce can lower the risks of contracting diseases due to certain root vegetables.