The decreased susceptibility of Syrian hamsters to Opisthorchis felineus invasion after its repeated administration

: The investigations conducted on Syrian hamsters have revealed that multiple enteral infusions of cold inactivated (t = -10 degrees C) O. felineus metacercariae resulted in the formation of immunocompetent cell and fibroblast infiltrations around the branches of the portal vein. The infestation of animals by viable pathogens led to reduced accommodation of helminths and suppressed cell infiltration in the liver. It is assumed that the native population of the foci become tolerant to the disease with the penetration of noninvasive Opisthorchis larvae into their body and the development of latent forms of helminthiasis.