Leishmaniasis is a neglected tropical disease caused by Leishmania protozoa and 
associated with three main clinical presentations: cutaneous, mucocutaneous and 
visceral leishmaniasis. Visceral leishmaniasis is the second most lethal 
parasitic disease after malaria and there is so far no human vaccine. Leishmania 
donovani is a causative agent of visceral leishmaniasis in South East Asia and 
Eastern Africa. However, in Sri Lanka, L. donovani causes mainly cutaneous 
leishmaniasis, while visceral leishmaniasis is rare. We investigate here the 
possibility that the cutaneous form of L. donovani can provide immunological 
protection against the visceral form of the disease, as a potential explanation 
for why visceral leishmaniasis is rare in Sri Lanka. Subcutaneous immunization 
with a cutaneous clinical isolate from Sri Lanka was significantly protective 
against visceral leishmaniasis in BALB/c mice. Protection was associated with a 
mixed Th1/Th2 response. These results provide a possible rationale for the 
scarcity of visceral leishmaniasis in Sri Lanka and could guide leishmaniasis 
vaccine development efforts.