[Perspectives of the control of Opisthorchis invasion by the method of treating the molluskan population].

Sanitation of the mollusk population with highly effective cercaricide preparations can be used for the control of opisthorchosous infection. Low concentrations of molluskocides which are sublethal for non-infected mollusks have turned to be lethal for hyperinfected individuals. All tested molluskocides display a cercaricide effect in concentrations which are considerably lower than molluskocide ones. Low concentrations of cercaricides are toxic both for cercariae and parthenites from the liver of mollusks and for freely swimming cercariae. Disastrously affecting the freely swimming cercariae microdoses of cercaricides prevent the infection of the second intermediate hosts. Microdoses of cercaricides which are lethal for cercariae are not toxic for the majority of hydrobionts including fishes of all age groups. As far as the dynamics of the infection level of Bithynia with O. felineus is characterized by a one-peak curve with a distinct peak in the middle-end of July the treatment of water bodies with microdoses of cercaricides should be carried out just in this period.