Kala azar (KA) or visceral leishmaniasis (VL) is endemic in several districts of Bangladesh with the highest incidence in Mymensingh, Pabna and Tangail districts. ICDDR,B is involved in a project for improving the surveillance of KA in Trishal, Mymensingh since 2005. Improvement of case detection is necessary for both surveillance purposes and better control. The aims of this pilot study are to assess some newer techniques for diagnosis of KA using blood and urine samples of suspected cases; and evaluate response to treatment with sodium stibogluconate to which resistance has been reported in India, considered to be a part of the same zone harboring the disease agent Leishmania donovani and transmitted by the same vector Phlebotomas argentipes (sand-fly). No data is currently available on response to sodium stibogluconate in KA patients in Bangladesh. Although a number of new drugs have been evaluated in the treatment of KA in India and Kenya, no trial has so far been conducted in Bangladesh. A team of researchers from GlaxoSmithKline (UK) had recently visited Bangladesh to evaluate if it would be possible to conduct a Phase-III clinical trial with sitamaquine. They interacted with scientists of ICDDR,B and expressed their interest to help develop ICDDR,B's capacity in order to include Bangladesh as one of the sites for the planned, multi-centre, Phase-III trial of sitamaquine; India and Nepal are two other possible sites for the trial. The aims of the proposed study are to train physicians and laboratory personnel in preparation for the future drug trial(s) on KA as well as to compare different tests for its diagnosis that might improve case detection at the field level and used for research purposes. The investigators will also examine in greater detail the different Leishmania species circulating in the area of Mymensingh and whether treatment failure and occurrence of Post Kala azar Dermal Leishmaniasis (PKDL) is associated with certain species.