title: From the donor's arm to blood product: a study on bacterial contamination of apheresis platelet concentrates.
abstract: BACKGROUND
  Transfusion-associated bacterial infections are a quite frequent collateral effect of administration of platelet concentrates (PC). We carried out a microbiological surveillance of bacterial contamination of apheresis platelet concentrates by studying microbial flora on donors' arms before and after skin disinfection, through blood cultures with the diversion volume and with the PC.
  
  
  METHODS
  Platelet aphereses were carried out using two Haemonetics MCS+ instruments. Cutaneous swabs were examined by the direct plate technique and blood cultures were performed using Bact/ALERT aerobic bottles. In the 5 years from January 2001 to December 2005 we tested 481 PC.
  
  
  RESULTS
  Cutaneous swabs showed significant bacterial growth in 89% of cases before skin disinfection and in 44% after. None of the blood cultures performed on diversion blood was positive, one (0.2%) PC was positive on the fifth day after collection and the presence of a Staphylococcus epidermidis strain was demonstrated.
  
  
  CONCLUSIONS
  Our results suggest that the skin disinfection protocol adopted in our structure is not fully satisfactory. The cultures performed on the PC showed a low prevalence of contamination, and the only positive sample was contaminated by a common skin contaminant (S. epidermidis). The culture became positive on the fifth day after collection, but on the second day the PC had been transfused to a patient, without any adverse reaction. In our experience a culture method using Bact/ALERT aerobic bottles was not able to prevent transfusion of the only contaminated PC identified in this study.
authors.affiliation: Centro Trasfusionale A-ULS 14.
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Leo
authors.forename: Maria Monica
authors.initials: MM
authors.lastname: Salvadego
authors.forename: Maria Grazia
authors.initials: MG
authors.lastname: Piva
authors.forename: Graziano
authors.initials: G
authors.lastname: Ruffato
authors.forename: Sara
authors.initials: S
authors.lastname: Valverde
authors.forename: Ernesto
authors.initials: E
authors.lastname: Trabuio
authors.forename: Francesco
authors.initials: F
authors.lastname: Antico
authors.forename: Gianluca
authors.initials: G
authors.lastname: Gessoni