The significance of bacterial contamination in transfusion medicine and strategy to reduce patient morbidity and mortality

• Main Author: McDonald, Carl Peter
• Published: University of Sunderland 2008
• Subjects: 615.1; Biomedical Sciences
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.576528

Bacterial transmission is the major cause of microbe associated morbidity and mortality in transfusion recipients. In these studies initially the actual clinical impact was assessed and bacterial contamination rate determined in blood components. Until the late 1990 s, no effective intervention had been introduced in the UK to reduce the transmission of bacteria by transfusion. Three strategies were developed: improved donor arm disinfection, diversion of the first 20ml of donated blood and bacterial screen testing of platelet concentrates. These interventions have now been implemented by the National Blood Service (NBS) and other blood services worldwide. Improved donor arm disinfection was shown to be 10 times more efficient than existing practice and reduced bacterial contamination in whole blood by 57% and reduced clinically apparent transmissions by 65% (from 17 to 6 cases per million). Diversion reduced contamination in whole blood by 47% and clinically apparent transmissions from platelet concentrates by 76% (from 21 to 5 cases per million) and 100% in red cell units (previously 0.3 cases per million). BacT/ALERT was adapted for screen testing platelet concentrates and is now used routinely for shelf life extension. Pall eBDS was developed and enhanced by the National Bacteriology Laboratory of the NBS on a collaborative basis for the same purposes. These studies provided data which facilitated Certificate European marking and Food and Drug Administration approval for both systems. Both systems have now been implemented throughout the world and are market leaders. Scansystem (a rapid assay) was investigated, but was not considered suitable for routine use. Screen testing of all NBS platelet concentrates is now under consideration by the service. The studies undertaken have made a significant contribution to knowledge and have helped improve blood transfusion practice worldwide. Practicable and cost effective interventions supported by scientifically robust data have resulted in a marked reduction in transfusion-transmitted bacterial reactions, thereby improving the safety of the blood supply.