Analysis of Bacterial Detection in Whole Blood–Derived Platelets by Quantitative Glucose Testing at a University Medical Center

Abstract

After the March 2004 implementation of American Association of Blood Banks standards regarding platelet bacterial detection, we began quantitative glucose screening of whole blood-derived platelets (WB-P). The glucose level was measured immediately before component release--often storage day 4 or 5--using the Glucometer SureStep Flexx Meter (LifeScan, Milpitas, CA), with a positive cutoff of less than 500 mg/dL; failing units were cultured and not transfused. During 29 months (March 1, 2004-July 31, 2006) 93,073 units of WB-P were tested. Initially, 929 units (0.998%) screened positively. Bacterial growth was culture-confirmed in 6 units, for a bacterial contamination incidence of 0.006% and a true-positive rate of 6.4/100,000. Three additional culture-confirmed contamination cases were detected in transfused units causing febrile nonhemolytic reactions, for a false-negative rate of 3.2/100,000. Our overall contamination prevalence was 9.6/100,000 units of platelets transfused, lower than ordinarily cited, and showed a false-negative rate remarkably congruent to that of culture: 3.2/100,000. A low-sensitivity screening test applied late in platelet shelf-life can be comparable to culture in preventing bacterial-related morbidity.

Evaluation of the Sensitivity and Specificity of Use of Glucose and pH for Bacterial Screening of Platelet Concentrates Compared to the Bact/Alert

“…Bacterial contamination is considered the third most common cause of death overall from transfusion reported to the US Food and Drug Association (FDA), following transfusion-related acute lung injury and hemolytic reactions. The sepsis related mortality risk of platelet transfusion is ranging from 1/20,000 to 1/85,000 donor exposure [4]. The exact incidence of bacterial contamination of blood products reported by different studies is unknown because of using variable methods of bacterial detection [5].…”

Retrospective Study of the Prevalence of Bacterial Contamination of Platelet Concentrates in Morocco

“…With the exception of Staphylococcus aureus which can causing a serious problems, 14 most of the time, these bacterial species found in this study are generally associated with non-fatal septic transfusion reactions. 15 It is well known that these species do not grow at low temperatures (between 2°C and 6°C) which correspond to the storage temperature of Red cell. They however will under ideal storage temperature (22°C ± 2°C).…”

Blood safety: bacterial screening of blood products

“…Measurement of pH and glucose, or evaluation for swirling, is simple and inexpensive, but not sufficiently sensitive or specific for routine use in detection of bacterial contamination [36–38].…”