Inactivation of dengue virus in plasma with amotosalen and ultraviolet A illumination.

BACKGROUND: Dengue virus (DENV) is the most prevalent arbovirus in tropical and subtropical regions. Transfusion-transmitted DENV infections have already been reported and the risk for blood products to be contaminated by DENV needs to be considered in dengue-endemic areas, especially during outbreaks. Blood product inactivation processes, including amotosalen and ultraviolet A (UVA) illumination, have been developed to reduce transfusion-transmitted infections. In this study we demonstrate the efficiency of using amotosalen and UVA illumination for DENV inactivation in human plasma. STUDY DESIGN AND METHODS: Plasma units from volunteer blood donors were spiked with DENV. Viral titers and viral RNA loads were measured in plasma before and after amotosalen and UVA photochemical treatment.
RESULTS: The mean DENV titer in plasma before inactivation was 5.61 log 50% tissue culture infectious dose (TCID50)/mL and the mean viral RNA load was 10.21 log copies/mL. In inactivated plasma, the mean DENV RNA load was 9.37 log copies/mL, but cell cultures inoculated with inactivated plasma did not result in infected cells and did not produce any replicative virus nor detectable viral RNA.
CONCLUSION: We report here that amotosalen combined with UVA light inactivated DENV in fresh-frozen plasma (5.61 log inactivation of viral titer). This inactivation process is an efficient method to prevent plasma transfusion-transmitted DENV infections.