Bacterial screening of platelet concentrates: results of 2 years active surveillance of transfused positive cultured units released as negative to date.

BACKGROUND

The BacT/ALERT system for bacterial monitoring of platelet concentrates (PCs) was introduced in the Netherlands in 2001. Samples are cultured for 7 days, and as a result of the short shelf-life of PCs, they are usually released as 'negative to date'. Therefore, some of the PCs have already been transfused at the moment of a positive signal in continued cultures in the BacT/Alert. It is unclear, however, whether these PCs are associated with more transfusion reactions.

METHODS

During a 2-year period clinical data were collected from all patients who received PCs released as 'negative to date' but with a positive bacterial culture after being transfused.

RESULTS

Data of 158 patients who received PCs with confirmed positive bacterial culture tests were analysed. Two patients developed a transfusion reaction. In both PCs, Propionibacterium was cultured. The imputability as related to the transfusion was classified as unlikely in both patients.

CONCLUSION

Two of 158 transfusions of PCs released as 'negative to date', but with a confirmed positive BacT/ALERT result, were initially associated with transfusion reactions. However, the imputability of both reactions was low.