Prevalence of bacterial contamination of standard platelet units: a prospective study.

Background - Platelet concentrates contaminated with bacteria are a main so urce of transfusion-associated sepsis. Several studies have reported a very wide incidence (0-10%) of contamination. The aim of this study is to asses s the prevalence of bacterial contamination of standard platelet units at t he regional blood transfusion center in Casablanca. Study design and methods - During 15.5 months, 3,458 platelet concentrates (PCs) were analysed. The plasma from the bag and the tube was humogenised. One-fifth of the tube contents were inoculated every day for five days in t wo tubes containing 2.5 mL of Tryptic soy broth. One tube was incubated at room temperature and the other at 37 degrees C for 24 hours. The bacteria w ere identified by standard procedures. Results - Twenty-five (0.72%) of 3,458 platelet bags were contaminated. Twe nty-two bacteria (gsm,) were found in the platelet bags stored three days o r more, of which 14 (56%) were Staphylococci coagulase negative, two Staphy lococcus aureus, one alpha-haemolytic Streptococcus, four bacillus cereus, one Enterobacter cloacae, one Escherichia Coli and two Xanthomonas maltophi lia. Conclusion - The incidence reported in this series is higher than that repo rted by most authors. (C) 2000 Editions scientifiques et medicales Elseveir SAS.