HISTO-PATHOLOGY OF HEPATIC AND PULMONARY GRANULOMATA EXPERIMENTALLY INDUCED WITH EGGS OF SCHISTOSOMA-MANSONI

Hepatic granulomata were experimentally induced in previously unexposed white mice, albino rats and golden hamsters by injecting viable exogenous eggs of S. mansoni via the mesenterico-portal system. Histopathologic studies of livers of these animals showed that the lesions were similar to those in infections resulting from exposure to cercariae as occurs in natural infections. Comparable observations made on the lungs of animals that received egg injections via their tail veins showed striking differences with respect to timing of the occurrence of various histopathologic stages, mean size of granulomata, cellular composition and pathologic manifestations.