Fact sheet
Preventing infections from contaminated platelet transfusions
Despite longstanding screening procedures and recent advances in assay development, bacterial
contamination in platelets still represents a serious, yet preventable, risk for patients who need platelet
transfusions. More people die each year from bacterial contamination in platelets than any other
transfusion-transmitted disease, including HIV and hepatitis.
The estimated number of septic reactions due to bacterial contamination in platelets is more than 300
cases a year, but experts agree that the number is likely much higher due to under-reporting.
In a recent commentary by transfusion experts (click here) that appears in an early view of the peerreviewed journal Transfusion, the conclusion states “…There is a current and ongoing need for more
robust platelet bacterial testing. Even today, bacterial contamination of platelets remains a major cause of
sepsis and death despite the implementation of culturing.”
The problem – platelets susceptible to bacteria growth
Platelets are uniquely vulnerable to bacteria growth because they are stored at room temperature.
Bacteria can originate from the skin surface at the time of collection, from the blood donor, or during
platelet processing.
Every year, more than 2 million platelet doses are transfused in the United States. Recent studies estimate
that despite current screening methods, 1 in 2,000 to 3,000 platelet transfusions are still contaminated with
bacteria, which can cause severe to fatal reactions in patients. For comparison, the risk of acquiring a
transfusion-transmitted viral infection, such as HIV, is less than 1 in 1 million.
Bacterially-contaminated platelets can cause sepsis, a life-threatening infection in the bloodstream that can
spread to multiple organs. Experts believe many of these reactions go under recognized and unreported
because the signs and symptoms (fever, rigors, blood pressure changes) are similar to septic reactions
from other causes, particularly in patients with serious underlying conditions such as cancer.
Current tests have known limitations
In 2003, the international association for transfusion medicine and cellular therapies, AABB, established a
standard that required its member organizations to take measures to limit and detect bacterial
contamination in all platelet products. To meet this standard, U.S. collection centers today are nearly
universally using culture-based quality control assays.
The College of American Pathologists also added culture testing to detect bacterial contamination in
apheresis platelets to the transfusion medicine checklist for the Laboratory Accreditation Program.
(Apheresis is a major method for collecting platelets for transfusion.)
Culture tests are performed 24 hours after an apheresis platelet donation, following which blood centers
analyze results and dispose of bacterially-contaminated units. But platelets have a five-day shelf life and
bacteria levels just 24 hours after donation may be too low for detection by culture.
Recent studies show that early culture testing misses an estimated three of every four bacterially
contaminated units, which are then released to hospitals for transfusion. A hospital-based testing method,
the Verax Platelet PGD® test, is widely available, proven effective, affordable, and is approved by
regulators in the United States and Europe.
Vital for cancer patients
Platelet transfusions are typically needed to prevent or treat bleeding in individuals undergoing
chemotherapy for cancer, cardiovascular surgery, following major trauma, and in patients who are not able
to produce platelets.
The majority of platelet recipients, however, are cancer patients and others with immune disorders. Cancer
patients may require 40 or more platelet transfusions to restore blood cells destroyed through
chemotherapy treatments. Since cancer patients can be immune-deficient and therefore susceptible to
infection, a platelet transfusion contaminated with bacteria can be fatal.
A day-of-transfusion test is available
In 2007 the Platelet PGD® test for detecting bacteria in platelets was cleared by the U.S. Food and Drug
Administration for use at the hospital site. The test is made by Verax, a company in Worchester, Mass.,
and marketed and sold globally by Fenwal, Inc. of Lake Zurich, Ill.
A recent study published in the peer-reviewed journal Transfusion (link to study) demonstrates that the
Verax Platelet PGD® test is an important safety measure than can help prevent patients from receiving
bacterially-contaminated platelet units missed by culture tests.
Following publication of the data, the FDA in September 2011 said the test can be labeled and marketed
as a “safety measure,” the first time the agency has used this designation for a bacterial detection test for
platelets. The recent FDA clearance also clarified that the test can be performed within 24 hours of
transfusion.
The average cost in the U.S. to treat a patient with sepsis is $22,000 (click here for information), and is
typically much higher for patients with serious underlying conditions, such as cancer. The average cost of
the Platelet PGD® test is approximately $25.
The Platelet PGD® test detects bacteria missed by culture testing and enables clinicians to prevent
potentially deadly infections in patients. The test takes a few minutes to perform, and results are ready in
less than 30 minutes. However, without clear direction from a regulatory body or voluntary accreditation
agency, it is unlikely to become standard practice and accessible to all patients requiring a platelet
transfusion.