The pathology of experimental visceral leishmaniasis in resistant and susceptible lines of inbred mice.

: 1. The main pathological features of experimental visceral leishmaniasis were characterized in resistant and susceptible inbred mouse strains. 2. Disseminated granulomas containing parasitized macrophages were found especially in the liver and spleen of two inbred mouse strains, i.e. the resistant DBA/2 and the susceptible C57BL/10 strains, which had been inoculated with Leishmania donovani chagasi amastigotes. 3. The lesions tended to remain granulomatous in nature even during the early acute phase of the more susceptible mouse strain (C57BL/10), and later evolved to a decrease in number of parasites and granulomas and in granuloma diameter. However, no healing occurred up to the end of the observation period of 70 weeks for the C57BL/10 strain. 4. Visceral leishmaniasis in the mouse model does not resemble the classical human Kala-azar, but seems to be more related to oligosymptomatic forms seen in humans living in endemic areas.