Screening for Bacteria in Whole Blood Derived Platelet Products

1. Screening for Bacteria in Whole Blood Derived Platelet Products MAABB Dessert Meeting Fairfax, VA February 26, 2004

2. Bacterial Detection in Platelets:The Challenge Regulatory Challenge AABB Standard for Blood Banks and Transfusion Services 5.1.5.1 CAP Checklist item TRM.44955 (Phase I deficiency) Patient Safety Challenge Septic transfusion reactions remain among the top 3 causes of reported transfusion fatalities. Estimated that 1 in 1000 platelet units may be contaminated with bacteria.

3. Bacterial Detection in Platelets:The Challenge Requirements: Fast Cheap Easy Good Minimize product waste caused by false positives Minimize safety risks caused by false negatives “Don’t let the perfect be the enemy of the good” – Doing something may be better than doing nothing.

4. Bacterial Detection in Platelets:1st Generation Solutions Single Donor Platelets - Cultured by blood center Whole Blood Derived Platelets pH and Glucose testing using Multistix 10 SG reagent strips Fast: 5-10 minutes to test 5 units for a platelet pool Cheap: $1.60 per pool of 5 units Easy: materials common in hospital labs, eye readable color endpoints Good…well…possibly safer than nothing: 18,153 tests done, 93 failures (0.5%; 1 in 200). 89 of the 93 were tested with Gram’s stain and culture – no evidence of bacteria detected. More failures in air-shipped imports (2.2%; 1 in 45) than ground shipped locals (0.1%; 1 in 1000). During this time, all platelets associated with possible transfusion reactions were cultured, and no evidence of bacteria was detected.

6. Bacterial Detection in Platelets:1st Generation Solutions Reagent Strip testing for Whole Blood Derived Platelets Multistix 10 SG pH readings: 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5 Glucose readings: 0, 100, 250, 500, 1000, 2000+ ”The color blocks…represent nominal values; actual values will vary around the nominal values.” ~ Bayer Package insert UVA Failure/Rejection Criteria: pH reading of 6.5 or less, or glucose reading of 100 or less UVA Pass/Acceptance Criteria: pH reading of 7.0 or greater, and glucose reading of 250 or greater

7. Bacterial Detection in Platelets:Conclusions Does reagent strip testing have the potential to miss a contaminated unit? Yes Does reagent strip testing have the potential to detect a heavily contaminated unit? Yes The universal implementation of bacterial culture procedures, or another direct test for bacteria, will make reagent strip screening unnecessary. Until this occurs, reagent strip screening will satisfy accreditation requirements, and may contribute to transfusion safety.