Features of the first intermediary host distribution of Opisthorchis felineus near the major cities of KhMAO–Ugra (Western Siberia)

In this paper the dynamics of invasion extensiveness of freshwater Bithyniidae snails by trematodes Opisthorchis felineus (cat fluke) in the waters of Khanty-Mansi Autonomous Area was determined. The study was conducted for the Ob river (Surgut) and the Irtysh river (Khanty-Mansiysk) for 7 years. As a result of the study, it was determined that the population density of snails and the extensiveness of their invasion by O. felineus trematodes are higher in the Irtysh River, which is associated with the hydrological regime of the river. Indicators of invasion extensiveness are higher for Bithynia tentaculata snails than Bithynia troscheli.