Extension of platelet shelf life with an improved bacterial testing algorithm
Bibliographic record
Abstract
BACKGROUND: At Canadian Blood Services, platelet concentrate (PC) shelf life was extended to 7 days with a large-volume, delayed-sampling bacterial screening algorithm. We present the development study and postimplementation results. STUDY DESIGN AND METHODS: In the development study, PCs inoculated with five bacteria (various concentrations) were incubated for 7 days with daily sampling for BacT/ALERT cultures and bacterial quantification. After implementation, from August 2017 to December 2019, a total of 223 156 pools and 39 725 apheresis units and 5310 outdated PCs were screened. Since March 2018, cocomponents associated to false-positive results have been released to inventory. RESULTS: In the development study, Klebsiella pneumoniae, Serratia marcescens, and Staphylococcus aureus were detected at concentrations of at least 0.01 colony-forming units (CFUs)/mL at 24 hours postinoculation. However, Staphylococcus epidermidis was detected at concentrations of less than 0.16 CFUs/mL only more than 48 hours postinoculation. After implementation, 776 (0.35%) and 303 (0.77%) initial-positive results and 201 (0.09%) and 16 (0.04%) confirmed-positive results were obtained for pools and apheresis units, respectively, predominantly with Cutibacterium acnes. Other organisms included staphylococci, streptococci, Klebsiella oxytoca and Pseudomonas aeruginosa. One nonfatal reaction involving a 7-day pool contaminated with S. epidermidis occurred. Approximately, 1-in-1000 false-negative screening results were obtained during testing of outdated PCs. Approximately 1000 cocomponents associated with false-positive results were released into inventory. Combined PC outdating at Canadian Blood Services and hospitals was reduced from 18.9% to 13.1%. CONCLUSION: Screening of 7-day PCs increased bacterial detection mainly of anaerobes and reduced outdating. The incidence of septic transfusion events has decreased approximately threefold. A longer surveillance period is needed to evaluate the value of anaerobic cultures and residual safety risk.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".