RESUMO
To assess the potential for leishmaniasis being transmitted through blood transfusion, we studied the survival of Leishmania in blood products under blood bank storage conditions. We report that L. tropica- or L. donovani-contaminated transfusable blood products are a risk to the blood supply for at least 25 days postdonation under blood bank general conditions. The blood components that have been implicated are whole blood, packed red blood cells, platelet concentrate, and frozen-deglycerolized red blood cells, but not, as would be expected, fresh frozen plasma. Blood units containing four infected monocytes per milliliter of blood with a mean of three amastigotes per monocyte contain viable parasites for 15 days under blood bank storage conditions. Furthermore, animal studies showed the presence of parasites in the blood of cutaneously infected animals and the possibility of transmitting the disease to healthy experimental animals by blood transfusion from infected animal donors. Three of three BALB/C mice showed metastasis to the lower extremities and face after they received 0.25 ml of blood from a CPDA-1 bag seeded with 1.5 x 10(5) amastigotes per ml of blood kept under blood bank conditions for 30 days. This proves that Leishmania not only survives blood banking procedures and storage conditions but that the parasite retains its infectivity. The results of this study and the recent demonstration of L. tropica-infected monocytes in the blood of a patient returning from Southwest Asia suggests that transfusion-associated leishmaniasis can occur.