Detection of bacterial contamination in apheresis platelet products: American Red Cross experience, 2004

Abstract

BACKGROUND: Routine quality control (QC) testing for bacterial contamination in apheresis platelet (PLT) products was implemented in all 36 regional blood centers of the American Red Cross in March 2004. STUDY DESIGN AND METHODS: PLT samples were cultured under aerobic conditions until the end of the product shelf life or when a positive reaction was indicated. To confirm the initial positive reaction, a new sample was taken from the unit for reculturing. All positive culture bottles were referred for bacterial isolation and identification. Bacterial testing data along with apheresis PLT collection information were collected for analysis. Reports and investigations of potential septic reactions to apheresis PLTs were reviewed. RESULTS: In the first 10 months of bacterial testing, 226 of 350,658 collections tested initially positive. Sixty-eight were confirmed on resampling to be bacterially contaminated for an overall confirmed-positive rate of 0.019 percent or 1 in 5157. Staphylococcus spp. (47.1%) and Streptococcus spp. (26.5%) were the most frequently isolated bacteria; Gram-negative bacteria accounted for 17.6 percent of the confirmed-positive products. Of the 354 apheresis PLT products derived from all 226 initial test-positive cases, 38 (10.7%) were transfused by the time the initial positive reaction was indicated. None of these transfused products, however, had a confirmedpositive bacterial screen and no patient who had been transfused with an unconfirmed-positive product had evidence of a septic transfusion reaction. Three highprobability septic transfusion reactions to screened, negative components were identified. In all three cases, a coagulase-negative Staphylococcus was implicated. CONCLUSION: Our experience demonstrates that bacterial testing of apheresis PLT products as a QC measure was efficiently implemented throughout the American Red Cross system and that this new procedure has been effective in identifying and preventing the transfusion of many, although not all, bacterially contaminated PLT units.

Screening of platelet concentrates for bacterial contamination: spectrum of bacteria detected, proportionof transfused units, and clinical follow-up

“…A series of studies reports on the screening results of PCs with automated culture systems [3,4,6,7,[14][15][16][17]. Comparability of the results is limited.…”

Transfusion-transmissible infections and transfusion-related immunomodulation

“…[28]. Quality control testing for bacterial contamination of platelet products by culturing samples under aerobic conditions until the end of the product shelf life has been effective in identifying and preventing the transfusion of bacterially contaminated platelet units [29].…”

Platelets: Testing, Dosing and the Storage Lesion—Recent Advances

“…4 A large post-standard 5.1.5.1 study is also summarized in Table 1. 15 Over a 10-month period, apheresis platelets collected at 36 American Red Cross blood centers were cultured 24 hours after collection using the BacT/ALERT system. Products were eligible for release after 12 hours without a positive culture.…”

“…Reducing the risk even further may ultimately require alternative approaches, such as pathogen reduction. 15,[18][19][20] While the current culture systems have increased platelet safety, there are a number of costs: higher prices for platelets, 1-2% product loss from sampling and 12-30 hour delays in platelet product release, potentially affecting platelet availability. 21 It is hoped that these costs will be offset by the benefits of being able to extend platelet storage beyond the 5-day limit.…”