Blood :: Test to screen for bacterial contamination in blood platelets

The U.S. Food and Drug Administration has cleared for marketing the first rapid test to detect bacterial contamination in blood platelets prior to transfusion.

The Platelet Pan Genera Detection (PGD) Test System is a disposable test strip for use in a hospital transfusion service setting. It is intended to supplement current quality control testing methods used by blood establishments following collection of platelets using an automated instrument.

“The clearance of a rapid test is a significant step in the detection of bacterial contamination of platelets for transfusion,” said Jesse L. Goodman, M.D., M.P.H., director of FDA’s Center for Biologics Evaluation and Research. “In half an hour, a sample is prepared, processed and read, providing an additional assurance that the product is free from harmful bacteria.”

Platelets are used to prevent or treat bleeding in individuals undergoing chemotherapy for cancer, after major trauma, during or after surgery, and in individuals who do not produce platelets. Patients who are transfused with platelets contaminated with bacteria are at risk of developing a serious and potentially life-threatening infection of the blood stream known as blood poisoning. Blood poisoning must be treated quickly to prevent the infection from spreading to the heart and lungs.

Bacterial contamination of platelets is the leading infectious cause of transfusion-related patient fatalities. The risk of a patient receiving a transfusion contaminated with bacteria is 1 in 5,000 — far greater than the risk of transmitting hepatitis C virus (1 in 1.6 million) or HIV (1 in 1.9 million). To reduce the risk of transfusing contaminated platelets, blood centers culture samples of the platelets 24 hours after the donation. The culture is read within the next 24 hours (within 48 hours after the donation), and contaminated units are discarded. However, there is a possibility that the number of bacteria present at the time of culture may be so low that bacteria is not detected due to sampling limitations.

Rapid testing of blood platelets using the Platelet PGD Test System permits units of platelets to be retested at a time closer to their use. Although the test system is less sensitive than standard cultures, it is done later in storage when bacteria, if present, have multiplied, and thus are easier to detect.

The Platelet PGD Test System was developed by Verax Biomedica Inc., Worcester, Mass.

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