Visceral leishmaniasis (VL) or Kala-azar, a life-threatening parasitic infection, is often caused by various strains of Leishmania donovani, L. infantum, and L. chagasi and is endemic in Middle East and Mediterranean regions. Northwest and southern Iran are the primary foci for VL, which mainly affect children, therefore, L. infantum is expected to be dominant Leishmania strain in Iran (1-3)....