ABSTRACT
Several species belonging to the family Opisthorchiidae have been reported to infect humans, particularly the sh-borne liver ukes, Opisthorchis and Clonorchis. It is estimated that currently 45 million people are infected with liver ukes in Asia and Europe. Of these 35 million are infected with Clonorchis sinensis, 10 million with Opisthorchis viverrini sensu lato, and 1.2 million with O. felineus.1 As many as 680 million people worldwide are at risk of the infection.2 Moreover, in East and continental Southeast Asia where C. sinensis and O. viverrini occur, respectively, the incidence of cholangiocarcinoma (CCA), in which these species induce, is the highest worldwide.3 Metorchis species, which occur in both the Palearctic and Nearctic, are substantially more limited than the other three opisthorchids.4
