What Do You Mean – My Platelets Have Bacteria?

by G. Paranjape, M.D., Medical Director of Clinical Services, Carter BloodCare

Carter BloodCare used to perform quality control of apheresis platelets for bacteria by using a test called eBDS. This test allowed us to have a Pass/Fail (acceptable/not acceptable) result on day two and we only sent bacterially negative, or acceptable, products out to our hospitals. There was no need to call and notify hospitals about any change to test results once distributed.

As of December 2017, the eBDS methodology is no longer supported. Therefore, Carter BloodCare has implemented the use of BACT/ALERT® for bacterial detection in apheresis platelets. There is a change to the process with this new methodology.

The component must be held for 24 hours post collection and prior to inoculation; then incubated for an additional 24 hours prior to distribution to your hospital. The inoculated bottle remains incubated until the expiration of the component, which is 5 days post collection. It is possible that a positive result is detected after the platelet has been accepted by your hospital (or already transfused to a patient). If a positive alert is identified, we will call and notify the transfusion service to quarantine the component. This will prevent the relevant component from being transfused to a patient while we continue to investigate the initial positive result. Culture studies, including a gram stain, will be performed at our contracted microbiology lab. We will update the transfusion service of any preliminary and final results as they become available.

We encourage your transfusion service to notify you, the treating physician, of all results so a decision can be made either to monitor the patient more closely or give antibiotics as may be appropriate for a patient who may have been transfused. Remember, our Medical Directors are available for consultation 24/7 to answer questions or concerns associated with quarantine or recall notice of a platelet component.

Since Carter BloodCare went live with BACT/ALERT® we have tested approximately 5,000 samples and had a total of four positives, one of which was a true positive (skin contaminant) at our Bedford location. Our Tyler location has tested approximately 400 samples and has had zero positives.

It is common for most positive alerts to either be a false positive (gram stain negative or no growth) or grow a skin contaminant culture. Most donors are feeling well and healthy when they donate so the chance of having a pathogenic organism contaminating a platelet is quite slim.

If you have any questions about this methodology, or would like to consult with one of our medical directors, please call 817-412-5104 and ask to speak to a medical director.