Reduction of the risk of bacterial contamination of blood components through diversion of the first part of the donation of blood and blood components.

Abstract

The level of safety of transfusion therapy is now very high thanks to the combination of serological methods and genomic amplification used to screen for transmissible diseases and the meticulous care with which repeat, voluntary, unpaid donors are selected1–4. The main risk of transfusion-related infectious diseases is currently that of bacterial sepsis1,3–5. The risk of bacterial contamination of blood components is, in fact, estimated to be about three orders of magnitude greater than that of post-transfusional HIV and HCV infections5,6; the risk of bacterial sepsis causes by the transfusion of platelets is more than two orders of magnitude greater than the risk of the same viral infections5,6. According to a study published in 20047, the year in which bacteriological screening tests for platelet units were introduced in the USA3,8,9, the average prevalence of bacterial contamination in platelets from whole blood was 33.9/100,000 units, that of platelets from apheresis 51/100,000, while that of red cell concentrates was 2.6/100,000. The overall prevalence of bacterial contamination of units of cellular blood components was, therefore, about 1 in 3,000 donations (33.3/100,000)7,10. Table I reports the data on bacterial contamination of units of platelets and red blood cells derived from studies before 200311–19. More recent estimates indicate that bacterial culture tests on units of platelets are positive, and confirmed as such, in about 1 in 5,000 units (20/100,000)4. The risk of receiving platelet concentrates contaminated by bacteria is, therefore, considerably higher than the risk of post-transfusion infection by HIV, HCV, HBV and HTLV3,4. Table I Prevalence of bacterial contamination of cellular blood components recorded in studies before 2003