Background: The high incidence of septic transfusion reactions (STRs) led to testing being mandated by AABB from 2004. This was implemented by primary culture of single-donor apheresis platelets (APs) from 2004 and prestorage pooled platelets (PSPPs) from 2007.
Study design/methods: Platelet (PLT) aliquots were cultured at issue and transfusion reactions evaluated at our hospital. Bacterial contamination and STR rates (shown as rates per million transfusions in Results) were evaluated before and after introduction of primary culture by blood centers that used a microbial detection system (BacT/ALERT, bioMerieux) or enhanced bacterial detection system (eBDS, Haemonetics).
Results: A total of 28,457 PLTs were cultured during pre-primary culture periods (44.7% APs; 55.3% at-issue pooled PLTs [AIPPs]) and 97,595 during post-primary culture periods (79.3% APs; 20.7% PSPPs). Forty-three contaminated units were identified in preculture and 34 in postculture periods (rates, 1511 vs. 348; p < 0.0001). Contamination rates of APs were significantly lower than AIPPs in the preculture (393 vs. 2415; p < 0.0001) but not postculture period compared to PSPPs (387 vs. 198; p = 0.9). STR rates (79 vs. 90; p = 0.98) were unchanged with APs but decreased considerably with pooled PLTs (826 vs. 50; p = 0.0006). Contamination (299 vs. 324; p = 0.84) and STR rates (25 vs. 116; p = 0.22) were similar for PLTs tested by BacT/ALERT and eBDS primary culture methods. A change in donor skin preparation method in 2012 was associated with decreased contamination and STR rates.
Conclusion: Primary culture significantly reduced bacterial contamination and STR associated with pooled but not AP PLTs. Measures such as secondary testing near time of use or pathogen reduction are needed to further reduce STRs.
© 2020 AABB.