[Biological aspects of the problem of opisthorchiasis]

The paper reports the latest data concerning genesis and structure of opisthorchiasis area; biology, ecology, position in the system and distribution of the first intermediate hosts of Opisthorchis felineus; peculiarities of infections with Opisthorchis of the first and second intermediate hosts. The methods of chemical control of mollusks, the first intermediate host of Opisthorchis, are discussed.