AbstractBackground and Objectives
Blood components may be contaminated with commensal, pathogenic or environmental bacteria during collection, manufacture or storage. The outcome of transfusion is dependent on the ability of the specific strain to multiply to clinically relevant titres during storage, the pathogenicity of the strain and the patients' situation. Platelets in particular are stored in conditions conducive to bacterial growth, and septic reactions to these products are the most frequently documented infectious risk of transfusion.Materials and Methods
This update will use recent reports and unpublished data to describe our current understanding of the role of bacteria in platelet transfusion safety.Results
Historical data suggest that ˜1:1–3000 platelet products are contaminated with bacteria, and septic transfusion reactions occurred in 1:15 000–100 000 transfusions. Clinical awareness of the danger and a 2004 AABB standard requiring blood centres ‘to limit and detect bacteria’ in platelet products have driven the development of safety systems. The last decade has seen the implementation of optimal skin disinfection techniques and sample diversion strategies to reduce contamination, and many centres have implemented either bacterial culture testing or pathogen inactivation processes. Prerelease culture testing can reduce but cannot eliminate the risk of exposure to contaminated components. Pathogen inactivation technologies show variable efficacy at killing bacteria. Alternatively, assays performed on the day of transfusion prevent the transfusion of high concentrations of bacteria that are associated with the most severe adverse reactions.Conclusions
Bacterial contamination and sepsis remain the greatest infectious risks of transfusion. Enhanced testing or pathogen inactivation should be implemented to ensure patient safety.