Open-Label, Sequential Step, Safety and Efficacy Study to Determine the Optimal Single Dose of Ambisome for Patients With VL

Inclusion Criteria: * Male and female adults and children aged 4 years or older with no upper age limit (in accordance with manufacturer's instructions) * Acute, symptomatic, VL proven by parasitological examination of splenic aspirate (or bone marrow aspirate) with initial parasite index of at least 2+ * Haemoglobin \>4g/dL * Fever for more than 2 weeks * Living within reachable distance of the trial site to enable attendance for follow-up visits * Written informed consent to participate (for children, by parent or guardian) * HIV negative status Exclusion Criteria: * Patients 'in extremis' with signs/symptoms indicative of severe VL * Patients who have received any anti-leishmanial treatment within the last 6 months * Patients who have received any investigational (unlicensed) drugs during 6 months before recruitment * Known underlying chronic disease, such as severe cardiac, pulmonary, renal, or hepatic impairment. * Renal function tests (serum creatinine) outside the normal range * Liver function tests more than 3 times the normal range at study entry * Platelet count less than 40,000/ mm3 * Known alcohol abuse * Pregnancy or lactation * Concomitant acute drug usage for malaria and bacterial infection, pneumonia within last 7 days * Known hypersensitivity to AmBisome or amphotericin B * Any other condition which may invalidate the trial