Pathogen inactivation of Trypanosoma cruzi in plasma and platelet concentrates using riboflavin and ultraviolet light

Abstract Background Emigration of people infected with Trypanosoma cruzi to non-endemic areas has resulted in transfusion transmission to immunocompromised recipients. We studied the feasibility of inactivating T. cruzi using a new technology which utilizes riboflavin as a photosensitizer in combination with UV light, Mirasol PRT. Methods One billion T. cruzi organisms and 30 mL of 500 μM riboflavin were added to each of six units of human plasma and six units of platelets. To determine the level of detection of organism, a sample of each unit was cultured in tenfold serial dilutions beginning with 100 billion/250 mL as the starting culture. After 30 min, each unit was illuminated with 5.9 J/cm 2 of UV light (6.24 J/mL). The units were then cultured again in tenfold serial dilutions post-treatment. Results A 6 log reduction of pathogens was demonstrated in 5 of 6 units of plasma, and a 7 log reduction of pathogens was demonstrated in one unit. A 6 log reduction of pathogens was demonstrated in 3 of 6 units of platelets, a 7 log reduction was demonstrated in 2 of 6 units of platelets, and an 8 log reduction of pathogens was demonstrated in 1 of 6 units. Conclusions Mirasol PRT treatment demonstrated an ability to inactivate 5–7 logs of T. cruzi in plasma and platelets.