Infections of digenetic trematode metacercariae in freshwater fish from Banbyeon-cheon (stream) in Yeongyang-gun, Gyeongsangbuk-do, Korea

The present study investigated the infection status of digenetic trematode metacercariae (DTM) in freshwater fish from Banbyeon-cheon in Yeongyang-gun, Gyeongsangbuk-do, Korea. A total of 211 freshwater fish representing 11 species were examined using the artificial digestion method in October 2023. Six taxa of DTM, including Clonorchis sinensis, Metagonimus spp., Centrocestus armatus, echinostomes, Exorchis oviformis, and Metacercaria hasegawai, were detected. The overall prevalence of DTM was 92.4% among the fish examined. The prevalence of C. armatus was the highest (52.8%), followed by E. oviformis (51.6%), M. hasegawai (35.6%), echinostomes (31.0%), C. sinensis (16.1%), and Metagonimus spp. (6.9%) in positive fish species. The infection intensity of C. armatus was 126 metacercariae per infected fish, whereas those of C. sinensis and Metagonimus spp. were 20 and 5.8 per infected fish, respectively. These findings indicate that at least 6 taxa of DTM, including C. sinensis and Metagonimus spp., are prevalent to varying degrees in fish from Banbyeon-cheon in Yeongyang-gun, Gyeongsangbuk-do, Korea. However, the potential risk of fishborne zoonotic trematodes, particularly C. sinensis, appears to be markedly lower than that reported in previous studies.