Bacterial detection of platelets : current problems and possible resolutions
Faculty of Medicine and Health Sciences
Philadelphia :W b saunders co
Transfusion medicine reviews. - New York, N.Y.
, p. 259-272
University of Antwerp
The greatest transfusion-transmitted disease risk facing a transfusion recipient is that of bacterial sepsis. The prevalence of bacterial contamination in platelets and red blood cells is approximately 1 in 3000 units transfused. The available data indicate that transfusion-associated sepsis develops after 1 in 25 000 platelet transfusions and 1 in 250 000 red blood cell transfusions. One of the most widely used strategies for decreasing bacterial sepsis risk is bacterial detection. A roundtable meeting of experts was convened during the XXVIII Annual Congress of the International Society of Blood Transfusion (Edinburgh, UK, July 2004) to provide a forum for experts to share their experiences in the routine bacterial detection of platelet products. This article summarizes the presentations, discussions, and recommendations of the panel. The data presented indicate that some of the current bacterial screening technology is useful for blocking the issuance of platelet units that contain relatively high levels of contaminating bacteria. Platelet units are usually released based on a test-negative status, which often become test-positive only upon longer storage. These data thus suggest that bacterial screening may not prevent all transfusion-transmitted bacterial infections. Two transfusion-transmitted case reports further highlighted the limitation of the routine bacterial screening of platelet products. It was felt that newer technologies, such as pathogen inactivation, may represent a more reliable process, with a higher level of safety. The panel thus recommended that the Transfusion Medicine community may need to change its thinking (paradigm) about bacterial detection, toward the possibility of the pathogen inactivation of blood products, to deal with the bacterial contamination issue. It was suggested, where permitted by regulatory agencies, that blood centers should consider adopting first-generation pathogen inactivation systems as a more effective approach to reducing the risk of transfusion-associated sepsis than some of the approaches currently available. AN EXPERT PANEL roundtable meeting on bacterial detection convened was during the XXVIII Annual Congress of the International Society of Blood Transfusion in Edinburgh, UK, on July 13, 2004, under the chairmanship of Dr MA Blajchman. Appendix A provides a list of participants who attended. This roundtable meeting provided a forum for the panelists to discuss the current transfusion risks due to the bacterial contamination of platelet concentrates, the impact of the implementation of routine bacterial screening, the testing methods available, the necessary actions to be taken when a positive test is obtained, and the benefits and limitations of routine bacterial testing. The panelists presented the protocols they have in place in their institutions for bacterial detection and their experiences since first application of bacterial detection. Clinical cases were presented to highlight the problems associated with transfusion-associated sepsis. The panel recognized that the bacterial contamination of blood products is the most common microbiologic risk of transfusion. The prevalence of contamination of cellular blood products is reported to be approximately 1 in 3000 blood product units. The prevalence of significant clinical events is reported to be approximately 1 in 25 000 for platelet transfusions and 1 in 250 000 for red blood cell (RBC) transfusions.1 Underreporting and underrecognition are acknowledged as being considerable problems. The panel discussed such subjects as screening technology, when to sample, the sample volume, the clinical significance of anaerobic organisms, whether RBCs should be screened, the clinical significance of low levels of bacterial contamination, and which universally effective measures might be taken to reduce this readily preventable transfusion risk. The ultimate purpose of this roundtable meeting was to provide guidance on issues related to the bacterial detection in blood products. This report summarizes the presentations, discussions, and recommendations of the panel.