Thyer J, Perkowska-Guse Z, Ismay S L, Keller A J, Chan H T, Dennington P M, Bell B, Kotsiou G, Pink J M
Australian Red Cross Blood Service, Melbourne, Vic, Australia.
Vox Sang. 2018 Jan;113(1):13-20. doi: 10.1111/vox.12561. Epub 2017 Sep 26.
Australia introduced bacterial contamination screening (BCS) for platelet components in April 2008. This study presents analysis performed to assess the efficacy of testing.
Seven-day aerobic and anaerobic culture is performed using the BacT/ALERT 3D system. Following an initial machine positive (IMP) flag, all associated components are recalled, and/or clinicians treating already transfused patients are notified. IMPs are categorized as 'machine false positive', 'confirmed positive' or 'indeterminate' depending on culture results of initial and repeat samples.
Between 2010 and 2012, 1·1% of platelet donations tested IMP; since 2013, this rate has fallen to 0·6% through improved instrument management, reducing false-positive IMPs but maintaining sensitivity for cultures yielding bacterial growth. On average, 66% of confirmed positive and indeterminate platelet units had been transfused at the time of detection. The majority (95%) of these grew Propionibacterium sp., a slow-growing organism that rarely causes sepsis in the transfusion setting. The incidence of reported transfuion-transmitted bacterial infection (TTBI) has fallen since the introduction of BCS, with a 4·2-fold [0·5, 28·2] lower rate from platelets.
BCS has been successful in detecting platelet units containing pathogenic bacteria. The incidence of TTBI from platelets has fallen since the introduction of BCS, but the risk has not been eliminated due to rare false-negative results. In the absence of a pathogen inactivation system for red blood cells, BCS provides 'surrogate' testing of red blood cells from which platelets have been manufactured.
澳大利亚于2008年4月开始对血小板成分进行细菌污染筛查（BCS）。本研究对评估检测效果的分析进行了阐述。
使用BacT/ALERT 3D系统进行为期7天的需氧和厌氧培养。在机器首次出现阳性（IMP）提示后，召回所有相关成分，和/或通知治疗已输血患者的临床医生。根据初始样本和重复样本的培养结果，将IMP分为“机器假阳性”、“确诊阳性”或“不确定”。
2010年至2012年期间，1.1%的血小板捐献检测为IMP；自2013年以来，通过改进仪器管理，这一比例已降至0.6%，减少了假阳性IMP，但保持了对产生细菌生长的培养物的敏感性。平均而言，66%的确诊阳性和不确定血小板单位在检测时已被输注。其中大多数（95%）培养出丙酸杆菌属，这是一种生长缓慢的微生物，在输血环境中很少引起败血症。自引入BCS以来，报告的输血传播细菌感染（TTBI）发生率有所下降，血小板导致的TTBI发生率降低了4.2倍[0.5, 28.2]。
BCS已成功检测出含有致病细菌的血小板单位。自引入BCS以来，血小板导致的TTBI发生率有所下降，但由于罕见的假阴性结果，风险尚未消除。在缺乏红细胞病原体灭活系统的情况下，BCS为已生产血小板的红细胞提供了“替代”检测。
