[The ecological-epidemiological characteristics of opisthorchiasis in Sverdlovsk Province].

Opisthorchiasis has been recorded as the prevalent invasion in the adults over many years in the Sverdlovsk Region. The 1986-1991 studies have shown that there are Opisthorchis infection foci, by infecting 10.0-30.0% of the population, 12.0-73.0 of the Cyprinidae fish, and 0.2% of the Codiella mollusks in Sverdlovsk Province that is central in the middle Urals economic area. The irregular anthropogenic loading, such as the number of water reservoirs, specific features of their constructions and operation, in the river basins of the Sverdlovsk Region varies, by affecting the living conditions, spread of intermediate hosts and circulation of the vector, by predetermining the heterogeneous functioning of Opisthorchis infection foci. Some display their development, the others exhibit their regression due to unfavourable conditions for the vector in the impact areas of hydrological constructions. The areas that are different in the endemicity of opisthorchiasis and the nature of vector transmission were identified and characterized. There were 4 area types in terms of the nature of opisthorchiasis vector transmission.