Visceral leishmaniasis in the Sudan: comparative parasitological methods of diagnosis.

Patients with suspected kala-azar had aspirations of spleen, lymph node and bone marrow performed to compare the relative merit of each procedure. Splenic aspiration remains the method most likely to provide microscopic proof of leishmanial infection (18 of 19 samples) and was the only site positive in 5 patients. Lymph node aspirates contained parasites in 20 of 29 patients, whereas bone marrow aspirates provided the diagnosis in 18 of 28. Therefore, lymph node aspiration, with its minimal morbidity, is indicated as the primary diagnostic method in patients in the Sudan with suspected kala-azar. If negative, splenic aspiration should be performed.