The authors describe a therapeutic study in marmosets (Callithrix jacchus) of a strain of Leishmania donovani isolated from a fatal human case of Kala-azar. The patient failed to respond to antimoniais (Glucantime and Pentostam), Amphotericin B and pentamidine therapy. Skin tests for the evaluation of cellular immunity were negative with the exception of 2% dinitrochlobenzene. Four adult marmosets were inoculated intraperitoneally with a suspension of amastigotes of L. donovani isolated from the hamster liver and spleen. Two hundred and ten days later all the animals had amastigotes in aspirates obtained by liver puncture. Glucantime treatment 28 mg/kilogram body weightper day for 3 series of 10 days was begun in three animals while the fourth was kept as a control. The three treated animals became parasite free in contrast to the control marmoset. The fact that this strain of L. donovani was unresponsive in the patient, inspite of various attempts at treatment, and yet responded to antimoniais in marmosets suggest that the patients immune response was defective leading to a fatal outcome.
Kala-azar; Resistence to treatment; Experimental infection in marmosets