Human small liver flukes consist
of Opisthorchis felineus, Opisthorchis viverrini and Clonorchis sinensis.
O. felineus is found in some parts of the European Union and the former
Soviet Union, C. sinensis is found in eastern Asia, while O. viverrini is
found in the Greater Mekong Subregion: Vietnam, Laos, Myanmar,
Cambodia and Thailand (IARC, 2012).