02738nas a2200265   4500008003900000245013700039210006900176260000800245300000700253490000700260520196300267100001302230700001702243700002102260700002202281700001802303700001602321700001202337700001402349700001402363700001502377700001502392700001602407856004902423       2016                          d00aProbable and possible transfusion-transmitted dengue associated with NS1 antigen-negative but RNA confirmed-positive red blood cells0 aProbable and possible transfusiontransmitted dengue associated w  cJan  a150 v563 aBACKGROUND:  In the absence of active blood donation screening, dengue viruses (DENV) have been implicated in only a limited number of transfusion transmissions worldwide. This study attempted to identify if blood from donors testing negative by an NS1-antigen (Ag) enzyme-linked immunosorbent assay (ELISA) but confirmed positive for DENV RNA caused DENV-related disease in recipients during the epidemic years of 2010 to 2012 in Puerto Rico. STUDY DESIGN AND METHODS:  Donation aliquots testing negative by an investigational NS1-Ag ELISA were stored frozen and retested retrospectively using a research transcription-mediated amplification assay (TMA) detecting DENV RNA. All RNA-reactive donations were subject to confirmatory RNA and antibody testing. Recipient tracing was conducted for all components manufactured from TMA-reactive components. Medical chart review, recipient interview, and follow-up sampling occurred for 42 recipients transfused with TMA-reactive components. RESULTS:  Six of 42 recipients developed new-onset fever in the 2 weeks posttransfusion; three (50%) received RNA confirmed-positive, NS1-Ag-negative red blood cell (RBC) units. One recipient of a high-titer unit (7 × 10(7) DENV-4 RNA copies/mL) developed severe dengue, and a second recipient had only fever recorded but had a negative sepsis work-up. New fever attributable to DENV infection in a third recipient was confounded by fever potentially attributable to posttransfusion sepsis. CONCLUSIONS:  In our retrospective study, NS1-Ag detected 20% of all RNA confirmed-positive donations demonstrating limitations of NS1-Ag ELISA for blood donation screening. We identified one recipient with a clinical syndrome compatible with severe dengue who had received an NS1-Ag-negative but RNA confirmed-positive RBC unit. This investigation illustrates the difficulty in confirming transfusion transmission in dengue-endemic areas among severely ill transfusion recipients.1 aD, Matos1 aTomashek, KM1 aPerez-Padilla, J1 aMuñoz-Jordán, J1 aHunsperger, E1 aHoriuchi, K1 aNoyd, D1 aWinton, C1 aFoster, G1 aLanteri, M1 aLinnen, JM1 aStramer, SL  uhttps://www.notifylibrary.org/reference/4774