Visceral leishmaniasis (kala-azar): challenges ahead.

Indian visceral leishmaniasis (VL) is a parasitic disease caused by a haemoflagellete Leishmania donovani and transmitted by the bite of sand fly Phlebotomus argentipes. It affects various age groups. In India about 1,00,000 cases of VL are estimated to occur annually; of these, the State of Bihar accounts for over than 90 per cent of the cases. Diagnosis of VL typically relies on microscopic examination of tissue smears but serology and molecular methods are better alternatives currently. Notwithstanding the growing incidence of resistance, pentavalent antimony complex has been the mainstay for the treatment of VL during the last several decades. The second line drugs such as amphotericin B, lipid formulations of amphotericin B, paromomycin and recently developed miltefosine are the other alternatives. In spite of significant development in various areas of Leishmania research, there is a pressing need for the technological advancement in the understanding of immune response, drug resistance and the pathogenesis of leishmaniasis that could be translated into field applicable and affordable methods for diagnosis, treatment, and control of the disease.