[Experimental study of the permissivity of the wild rat (Rattus rattus) of Guadeloupe with regard to Schistosoma mansoni. Hypothesis on the role of this host in the dynamics of natural habitats (author's transl)].

Unlike the white laboratory rat, the wild rat (Rattus rattus) of Guadeloupe behaves as a permissive host with regard to Schistosoma mansoni, at least during a certain number of successive passages. The study of the host-parasite relationship of this couple has enabled us to demonstrate a certain number of fundamental differences in relation to the data furnished by the white rat; the worm recovery rate tested in the 4th week is more than twice as high as in the white rat (32% vs 11%), the "self cure phenomenon" is of a lesser intensity than in the white rat since the former involves only 45% of the worm population present at 4 weeks, the average size of adult Schistosomes is greater in the black rat (4.2 mm vs 3.62 mm), from the 6th week onwards one observes in R. rattus a transfer of adult worms from the mesenteric-bearing system towards the lungs, Schistosomes reproduce normally in the black rat with the production of fertile eggs in stools. In the light of these experimental data, the authors admit that, in certain station in Guadeloupe (freshwater mangrove), the rat is able to contribute to the maintenance of a threshold of parasitosis indispensible to the circulation of the parasite in the focuses of infection.