A microculture technique for isolating live Leishmania parasites from peripheral blood of visceral leishmaniasis patients.

Current procedures for diagnosing Leishmania parasites from patients involve invasive and dangerous tissue aspiration. We have developed a non-invasive and highly sensitive microculture method that can isolate parasites from the buffy coat of the patient's peripheral blood. The parasites were cultured in 96-well culture plates. Nineteen parasitologically proven visceral leishmaniasis (VL) patients were included in the study. Using this technique, we were able to isolate parasites from 16 (84%) samples. However, all 19 (100%) samples were positive on culture of splenic aspirates. We conclude that this technique is useful for the isolation and cryoconservation of parasites from patients' blood. This simple method could be tried as a first-instance alternative before other more sensitive procedures such as splenic aspirate; however, negative results should be confirmed by tests with higher sensitivity.