Geographic distribution. Endemic in Russia and occurs mainly in Siberia, Ukraine, and Kazazhstan.
Infection rate. Prevalence rates up to 85％ had been reported in certain areas of the USSR.
Life cycle. Similar to O. viverrini and C. sinensis. It lives mainly in the bile duct, gallbladder and pancreatic duct of mammalian hosts. The organism enters the human host by consumption of raw fishes.
Morphology. Adult worms measure 7-12 mm long and 1.5-3 mm wide.
Adult worm of Opisthorchis felineus.
Tai Soon Yong