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Updated: Apr 20, 2026
Routine Screening Method for Microparticles in Platelet Transfusions
Published on: January 31, 2018
Routine bacterial screening of platelet concentrates by flow cytometry and its impact on product safety and supply
B Müller1, G Walther-Wenke, M Kalus
1GRC-West Blood Donation Service, Central Laboratory Hagen, Hagen, Germany.
Background And Objectives:
Bacterial contamination represents the major infectious hazard associated with transfusion of platelet concentrates (PCs). As bacterial screening of PCs is not mandatory in Germany, the BactiFlow flow cytometry test has been introduced as a rapid detection method to increase product safety.
Materials And Methods:
During a period of 25 months, a total of 34 631 PCs (26 411 pooled and 8220 apheresis-derived PCs) were tested at the end of day 3 of their shelf life using the BactiFlow system. PCs initially reactive in BactiFlow testing and expired PCs not reactive in BactiFlow on day 3 were also investigated by the BacT/ALERT system and by microbiological cultivation in order to identify the contaminating bacterial species and to confirm reactive BactiFlow results.
Results:
Two hundred and twenty-eight PCs (0.7%) had an initially reactive result, 24 of them remained reactive in a second test run. Out of these reproducible reactive BactiFlow results, 12 could not be verified by parallel BacT/ALERT culturing, resulting in a confirmed false-positive rate of 0.03%. The bacterial species were identified as S. aureus, S. epidermidis, S. dysgalactiae ssp. equisimilis and B. cereus. In 10 out of 9017 expired PCs (0.11%), a confirmed-positive result was obtained in the BacT/ALERT system which had a negative result in the BactiFlow system.
Conclusion:
Testing of PCs by BactiFlow was successfully implemented in our blood donation service and proved sufficient as a rapid and reliable screening method. False reactive results are in an acceptable range since the transfusion of 12 bacterially contaminated PCs was prevented.
Insights
The BactiFlow flow cytometry test effectively screens platelet concentrates (PCs) for bacterial contamination, preventing unsafe transfusions. This rapid method proved reliable in a German blood donation service, with a low false-positive rate.
Area of Science:
- Transfusion Medicine
- Microbiology
- Medical Technology
Background:
- Bacterial contamination is a significant risk in platelet concentrate (PC) transfusions.
- Bacterial screening of PCs is not mandatory in Germany.
- The BactiFlow flow cytometry test was introduced to enhance PC safety.
Purpose of the Study:
- To evaluate the implementation and effectiveness of the BactiFlow system for bacterial screening of PCs.
- To determine the reliability and false-positive rate of the BactiFlow test.
- To identify bacterial species contaminating PCs.
Main Methods:
- A total of 34,631 PCs were tested using the BactiFlow system over 25 months.
- Reactive and non-reactive expired PCs were further analyzed using BacT/ALERT and microbiological cultivation.
- Bacterial species were identified for confirmed positive results.
Main Results:
- 228 PCs (0.7%) showed initially reactive BactiFlow results; 24 were reproducible.
- A confirmed false-positive rate of 0.03% was determined for BactiFlow.
- Identified contaminants included S. aureus, S. epidermidis, S. dysgalactiae, and B. cereus.
- 10 expired PCs showed contamination missed by BactiFlow but detected by BacT/ALERT.
Conclusions:
- BactiFlow testing was successfully implemented as a rapid and reliable screening method for PCs.
- The test demonstrated sufficient accuracy, with false reactive results within an acceptable range.
- The BactiFlow system prevented the transfusion of 12 bacterially contaminated PC units.
