Evaluation of Storage Conditions and Bacterial Proliferation in Blood Components

Abstract

616 LABMEDICINE Volume 35 Number 10 October 2004 labmedicine.com The safety of the blood supply, particularly the risk of transfusion transmitted infections, is a great public health concern. The transfusion of bacterially contaminated blood and blood products may have severe or even fatal consequences.1-4 Bacterial contamination of blood components is the most frequently reported cause of transfusion-related fatalities reported to the FDA after hemolytic transfusion reactions, accounting for more than 10% [77/694] of transfusion-associated fatalities from 1985 to1999.5 Of these, a majority (62%) were associated with the transfusion of bacterially contaminated platelets, while a minority (38%) were associated with transfusion of bacterially contaminated red cells. Platelets are stored at 22°C to 24°C and as a result are more likely to support bacterial growth than are the red cells, which are refrigerated between 1°C to 6°C. Review of literature6-16 on bacterial contamination of blood components reveals that there are no definite and clear cut guidelines or effective measures being practiced to tackle this problem, as not all contaminated blood components lead to overt clinical bacterial infections, and often there is lack of suspicion on the part of clinicians. Thus, there is not enough data in the literature to document the exact frequency of transfusion-transmitted bacterial infections, but reported values are around 0.1%.6 Recent figures estimate a prevalence of 0.2% for whole blood,6 0.002% to 1.0% for packed red cells, and 0.04% to 10% for platelets depending upon processing, storage, and the method of culture (Table 1).7-13 Much attention has been paid to the storage conditions and prevention of possible contamination during the collection and preparation of blood components in the blood bank,14-16 but the storage conditions and handling of blood and blood components outside the blood bank (ie, various wards and operation theaters) have never been looked into seriously. Keeping this in mind, we tried to evaluate: 1. The storage conditions within and outside the blood bank by sending random cultures of components stored in the blood bank and single cultures from received-back units from various wards and operation theaters. 2. The overall incidence of bacterial contamination of blood components at our center and the resultant morbidity and mortality over a period of 3 years, from January 1999 to December 2001. Evaluation of Storage Conditions and Bacterial Proliferation in Blood Components