Evidence of meaningful levels of Trypanosoma cruzi in platelet concentrates from seropositive blood donors.

Background: According to the reported cases of transfusion-acquired Trypanosoma cruzi infection, the risk of T. cruzi transfusion transmission appears to be higher with platelet (PLT) products than with other blood components. The aim of this study was to investigate by quantitative real-time polymerase chain reaction (qPCR) the parasitic load detected in leukoreduced plasma and PLT concentrates collected by apheresis from seropositive T. cruzi blood donors and compare them with peripheral whole blood (WB).

Study Design And Methods: During 2011 to 2013, a prospective study was carried out in a group of blood donors originating from Chagas-endemic areas but who are now living on the island of Majorca, Spain. Leukoreduced plasma and PLT concentrates were collected by apheresis from seropositive blood donors with detectable parasitemias in peripheral WB.

Results: Seropositivity was found in 23 of 1201 donors studied (1.9%), and T. cruzi DNA with less than 1 parasite equivalent/mL was detected in peripheral WB in 60.86% (14 of 23) of these. The study in blood components obtained by apheresis from these donors showed that T. cruzi DNA with a mean ± SD parasitic load of 5.33 ± 6.12 parasite equivalents/mL was detected in 100% of the PLT concentrate samples. Parasite DNA was undetectable in the extract taken from plasma collected from donors with a positive qPCR in peripheral WB.

Conclusion: The higher parasitic load found in PLT concentrates compared to plasma and peripheral WB would explain the higher transfusion transmission risk of Chagas disease associated with PLT transfusions described in the reported cases of transfusion-acquired T. cruzi infection.