Detection of Leishmania in immunocompromised patients using peripheral blood spots on filter paper acid the polymerase chain reaction

The aim of the present study was to investigate whether the polymerase chai n reaction could be used to detect Leishmania infantum in peripheral blood spots of immunocompromised patients. Although visceral leishmaniasis in imm unocompromised individuals is routinely diagnosed by direct microscopy or b y culture of biopsy material, both methods have disadvantages. In order to evaluate an alternative method of diagnosis, blood spots were collected on filter paper from 24 immunocompromised individuals with visceral leishmania sis diagnosed by bone marrow microscopy or culture. The samples were tested using the polymerase chain reaction. Leishmania DNA was detected in 15 of 20 patients who had not yet begun treatment for Leishmania infection and in two of four patients undergoing treatment. Using microscopy or culture, pa rasites were detected in 5 of 19 and 8 of 19 fresh blood samples, respectiv ely. The results suggest that the polymerase chain reaction can be used wit h blood spots on filter paper as an initial screening method for immunocomp romised patients suspected to have Leishmania infection.