Evidence for determining parasitic factors in addition to host genetics and immune status in the outcome of murine Leishmania infantum visceral leishmaniasis

C.B-17 SCID and congenic BALB/C mice were used to examine Leishmania infantum strain pathogenicity independently of host genetic factors. While parasite loads were significantly higher in immunodeficient mice than in immunocompetent mice, the kinetics of infection during a long-term follow-up were similar, suggesting that intrinsic parasitic factors also influence the outcome of L. infantum infection.