The positive amastigotes of VL identified on bone marrow smears from the case patient were sent to the Department of Parasitology, Phramongkutklao College of Medicine for species identification. DNA was extracted from the stained smears of bone marrow using modified FTA filter paper (Whatman, Bioscience, USA). Specific PCR primers as described by Uliana et al. (1994) and le Fichoux et al. (1999) were used to amplify the ITS1 regions of ssrRNA and kDNA genes, respectively. To confirm species identification, PCR-RFLP of the ITS1 region was performed using HaeIII endonuclease whilst PCR-RFLP of the mini-exon gene was performed using EaeI endonuclease (Marfurt et al., 2003b and Schönian et al., 2003). DNA extracted from an L. donovani reference strain (Biomedical Research, The Netherlands) was used as the positive control in all experiments.