Liver changes in hamsters infected with a liver fluke of man, Opisthorchis viverrini

Thirty male Syrian golden hamsters were each infected with 100 metacercariae of Opisthorchis viverrini. The hamsters were killed at 3, 7, 15, 30, 154 days of infection. The early pathological changes consisted of an acute inflammatory reaction involving the bile ducts of the second order and the portal connective tissue, especially the large veins, as well as focal coagulation necrosis of the liver lobules. As the flukes developed into adults they induced hyperplasia and adenomatous formations of the bile duct epithelium. There was also a granulomatous response to the adult flukes and eggs. Resolution of the granulomas led to periductal and portal scarring. These findings suggest that immunopathologic mechanisms may be important in the pathogenesis of liver fluke disease.