RESUMEN
This study was done to investigate the effect of Schistosoma mansoni infection on the morphology of bile ducts and liver tissue in experimental animals. Thirty-six golden hamsters were infected with 300 cercaria of Schistosoma mansoni. Six animals were sacrificed every four weeks post infection till the 16th week. The livers were dissected and the parts of common bile ducts were cut and were examined microscopically. Paraffin sections were prepared and stained with hematoxylin and eosine and with Van Gieson stains. The wall thickness of bile ducts were compared between infected and non infected. Extensive dilatation and thickening of bile duct walls were found in comparison with noninfected liver sections. In infected animals, there was four times increase in the thickness of duct wall in late weeks of infection. Focal necrotic lesions, and lymphocytic infiltration were scattered throughout liver parenchyma of infected animals. It has been suggested that Schistosoma mansoni which is a common parasite in Egypt release large amounts of proline and induces collagen deposition in bile ducts leading to marked periductal fibrosis