Published online by Cambridge University Press: 06 April 2009
The localization of adult Schistosoma mansoni originating from Guadeloupe (West Indies) was analysed in the natural host Rattus rattus in experimental and natural infections. A transfer of schistosomes from the porto-mesenteric system to the lungs occurs between the 4th and the 20th weeks post-infection, with a peak between 4 and 8 weeks; it should be noted that the worms start laying eggs at 4 weeks post-infection. In both experimentally and naturally infected R. rattus the relocation of schistosomes in the lungs is correlated with the total worm burden. Between 6 and 12 weeks post-infection some adult worms and numerous eggs are trapped in the liver. A high mortality in the worm population coincides with the migration of the parasites from the porto-mesenteric veins to the lungs. In re-infected R. rattus a relationship appears between the presence of schistosomes in the lungs and resistance to reinfection. It is concluded that, as already postulated previously in mice, resistance to re-infection in the natural host R. rattus is at least partly correlated with the hepatic pathology caused by the schistosomes of the primary infection.