Clinical and pathological effects of Echinostoma revolutum (Digenea: Echinostomatidae) in the golden hamster, Mesocricetus auratus.

Laboratory hamsters (Mesocricetus auratus) were infected with Echinostoma revolutum (Trematoda). Hamsters developed marked and sometimes fatal echinostomiasis. Clinical signs included progressive unthriftiness, watery diarrhoea and weight loss. Packed cell volume, haemoglobin and red blood cell counts increased in those animals with severe diarrhoea. No increase in eosinophils was noted in peripheral blood smears. Examination of tissues of infected animals showed wide individual variations related to the intensity of infection. The histopathological responses of hamsters to the parasite showed erosion of intestinal villi with lymphocytic infiltration being the primary response. Periportal lymphocytic infiltration and focal hepatic necrosis were observed in livers from some infected animals. The findings of this study are discussed in terms of variations in pathogenicity of E. revolutum and as a model for the study of echinostomiasis.