Visceral Leishmaniasis (VL) is a severe disease with high mortality, caused by parasite members of the L. donovani complex (1,2). The vector for transmission is the sand fly, whose carriers of infection are typically dogs (3-6). It is a disease endemic to many countries and is a serious problem in many developing nations, particularly with the increasing urbanization of populations (7). High incidence is encountered in parts of Latin America, East Africa, Middle East, India and China. It is endemic to countries bordering the Mediterranean such as Italy, Southern France, Spain, Portugal, and Northern Africa. In Southern Europe, VL has become the leading opportunistic infection in AIDS patients (8-15).

Diagnosis of acute VL is often attempted by aspiration of bone marrow for direct parasite identification. The procedure is invasive, painful, dangerous and has a low success rate due to the inability to always isolate parasites from the tissue. Alternatively, serodiagnosis is widely utilized since anti-leishmanial antibody titers are typically high during the acute disease phase. ELISA is the preferred laboratory test for serodiagnosis of VL, although indirect immunofluorescent antibody tests (IFAT) and direct agglutination tests (DAT), using whole parasites, are still widely used in conjunction with ELISA or alone (16-18).