Evaluating bacterial contamination detection methods in blood units returned over 30 minutes: Implications for transfusion safety in resource-limited settings

Background: The wastage of all blood components, such as RBCs, platelets (PLT), and plasma, poses a significant challenge for hospitals globally. Hemolysis and bacterial contamination occur when RBCs are stored and transported outside specified temperatures, potentially leading to severe symptoms upon infusion. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a precise method for identifying bacterial isolates in microbiology labs. This study aimed to evaluate and compare the performance of three methods—MALDI-TOF MS, BacT/ALERT, and a manual method—in detecting bacterial contamination in packed RBC units returned after 30 minutes, assessing their potential to enhance transfusion safety and inform the 30-minute rule in resource-limited blood bank settings. Methods: This cross-sectional study included donated Packed RBC units returned to Kasr Al-Ainy Hospital's blood transfusion center after being issued for more than 30 minutes from February 2022 to August 2022. Compared to other methods, MALDI-TOF MS was used to examine 200 returned blood units by the end of the six months to detect hemolysis and bacterial contamination. Results: The examination of 200 returned blood units showed that 12.5% exhibited an elevated percentage of hemolysis, 15% had increased potassium levels, and 16% had elevated LDH levels. When tested with MALDI-TOF MS, 1.5% of the returned blood units were found to be contaminated, compared to 1% using BacT/ALERT and 0.5% with the manual method. Conclusion: Based on this study, blood units returned beyond 120 minutes have increased hemolysis, potassium, and contamination risk, with MALDI-TOF MS proving effective for rapid contamination detection, unlike those at the period of 30-120 minutes. Implementing MALDI-TOF MS could enhance transfusion safety and reduce blood wastage in resource-limited settings.