Bacterial pre-release testing of platelets – the Australian Red Cross Blood Service clinical experience

The risk of bacterial transmission by platelet transfusion has been recognised internationally as the leading residual infections transfusion risk in the last decade. We describe the clinical and logistical aspects of bacterial contamination screening of platelets introduced in Australia in early 2008. Sampling occurs at 24 h, and platelets are released to hospitals ‘negative to date’. Bacterial screening detection of initial machine-positive (IMP) and all follow-up results are notified to transfusing laboratories. Results of screening between 2008 and 2010 found a significant rate of IMP samples (1.06%) with a true-positive/indeterminate rate of 0.18%. Components were already transfused in 32.5% of cases at time of initial notification. Confirmed cases of septic transfusion reactions have declined significantly since the introduction of pre-release platelet screening, reflecting an important additional improvement in transfusion safety in Australia.