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

Background: Emigration of people infected with Trypanosoma cruzi to non-endemic areas has resulted in transfusion transmission to inummocompromised 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 mu M 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. (C) 2007 Published by Elsevier Ltd.