Fifty-two Leishmania strains, obtained from human patients and dogs in a vi
sceral leishmaniasis focus in Sudan, were characterized by isoenzyme electr
ophoresis (15 enzymes). The phylogenetic analysis showed that the 7 Leishma
nia zymodemes obtained hold ancestral positions on the phylogenetic tree, s
upporting the hypothesis of an East African origin of visceral leishmaniasi
s.