A Comparative Study of Schistosoma mansoni Infections in Mice, Gerbils, Multimammate Rats and Hamsters

Abstract

Summary Qualitative differences in host response to Schistosoma mansoni infection were observed in mice, multimammate rats, hamsters and gerbils. Central necrosis within granulomas and hepatic parenchymal necrosis were most frequent in mice. The Hoeppli phenomenon was frequently observed about eggs in the multimammate rat but was not seen in other species. Granulomas in the hamster liver were characteristically histiocytic while those in the gerbil liver often contained numerous mast cells. Extreme dilatation of peripheral hepatic lymphatics was frequent in multimammate rats but uncommon in other species. Amyloidosis was a frequent complication of prolonged infection in hamsters. Peripheral edema, ascites and pleural effusions in this species were secondary to renal amyloidosis. Marked hyperplasia of bile ducts was observed only in mice. Fibrosis about these ducts was present in many mice with prolonged infections. Portal fibrosis and pylephlebitis were more marked in mice than in other species and were most marked in C3H mice. The resemblance of portal fibrosis to the pipestem fibrosis of human hepatic schistosomiasis was slight. Direct or indirect evidence of worm death was seen occasionally in mice with prolonged infections but was not noted in other species.