Bacterial contamination of platelet concentrates: results of a prospective multicenter study comparing pooled whole blood-derived platelets and apheresis platelets.
BACKGROUND
The GERMS Group initiated a prospective multicenter study to assess prevalence and nature of bacterial contamination of pooled buffy-coat platelet concentrates (PPCs) and apheresis platelet concentrates (APCs) by routine screening with a bacterial culture system.


METHODS
In nine centers overall, 52,243 platelet (PLT) concentrates (15,198 APCs, 37,045 PPCs) were analyzed by aerobic and anaerobic cultures (BacT/ALERT, bioMérieux).


RESULTS
In 135 PLT concentrates (PCs; 0.26%), bacteria could be identified in the first culture (0.4% for APCs vs. 0.2% for PPCs; p < 0.001). In 37 (0.07%) of these PC units, the same bacteria strain could be identified in a second culture from the sample bag and/or the PC unit. The rate of confirmed-positive units did not differ significantly between APC (0.09%; 1/1169) and PPC units (0.06%; 1/1544). Bacteria from skin flora (Propionibacterium acnes, Staphylococcus epidermidis) were the most prevalent contaminants. Median times to first positive culture from start of incubation were 0.7 and 3.7 days in aerobic and anaerobic cultures for confirmed-positive units. With a "negative-to-date" issue strategy, most PC units (55%) had already been issued by time of the first positive culture.


CONCLUSIONS
The rate of confirmed bacterial contamination of PC units was low. Nevertheless, clinicians must be aware of this risk. The risk of bacterial contamination does not warrant universal preference of APCs. It must be questioned whether routine bacterial screening by a culture method can sufficiently prevent contaminated products from being transfused due to the delay until a positive signal in the culture system and due to false-negative results.
Schrezenmeier
Hubert
H
Institute for Clinical Transfusion Medicine and Immunogenetics Ulm, Red Cross Blood Donor Service Baden-Württemberg-Hessia, and Institute of Transfusion Medicine, University of Ulm, Ulm, Germany. h.schrezenmeier@blutspende.de
Walther-Wenke
Gabriele
G
Müller
Thomas H
TH
Weinauer
Franz
F
Younis
Adelheid
A
Holland-Letz
Tim
T
Geis
Gabriele
G
Asmus
Jens
J
Bauerfeind
Ursula
U
Burkhart
Jürgen
J
Deitenbeck
Robert
R
Förstemann
Elisabeth
E
Gebauer
Wolfgang
W
Höchsmann
Britta
B
Karakassopoulos
Apostolos
A
Liebscher
Ute-Maja
UM
Sänger
Werner
W
Schmidt
Michael
M
Schunter
Friedrich
F
Sireis
Walid
W
Seifried
Erhard
E
D001419:Bacteria / Q000254:growth & development / Q000302:isolation & purification*; D001424:Bacterial Infections / Q000097:blood* / Q000209:etiology / Q000517:prevention & control; D001792:Blood Platelets / Q000382:microbiology*; D001793:Blood Preservation / Q000379:methods / Q000592:standards; D015169:Colony Count, Microbial; D006801:Humans; D017713:Platelet Transfusion / Q000009:adverse effects / Q000706:statistics & numerical data*; D010983:Plateletpheresis; D011446:Prospective Studies; D012307:Risk Factors