The epidemiology of bacterial culture–positive and septic transfusion reactions at a large tertiary academic center: 2009 to 2016

BACKGROUND: Bacterial contamination and associated septic transfusion reactions (STRs) remain the leading infectious risk to the blood supply. We sought to characterize the risk and clinical presentation of blood culture-positive transfusion reactions (BCPTRs) and STRs at our institution. STUDY DESIGN AND METHODS: A retrospective analysis was conducted of all suspected transfusion reactions reported to the transfusion service at a 1000-bed tertiary academic medical center from January 2009 to September 2016. Routine investigation included review of the clinical presentation, Gram stain, and bacterial culture of residual blood from the transfused product or associated blood bag. BCPTRs were defined by the presence of a positive bacterial culture in the blood product and/or recipient. STRs met definitive Centers for Disease Control and Prevention hemovigilance criteria for transfusion-transmitted infection, with definite imputability and concordant bacterial culture of the blood product and recipient. RESULTS: A total of 688,514 blood products were transfused during the study period, 3170 transfusion reactions were reported, and 18 (0.57%) were BCPTRs of which seven (0.22%) were STRs. Fifteen of 18 (83.3%) BCPTRs and six of seven (85.7%) were associated with transfusion of apheresis platelets. Major symptoms and signs of BCPTRs included chills (67%), fever (61%), and nausea and vomiting (50%). Four of seven (57.1%) STRs were classified as severe or life-threatening. CONCLUSION: BCPTRs are rare yet potentially serious. The signs and symptoms of BCPTRs, and associated STRs, are not specific, posing risk of misclassification. Challenges surrounding reporting and case ascertainment underscore the need for laboratory measures to address residual risk of contamination.