Satake Masahiro, Mitani Takako, Oikawa Shinji, Nagumo Hideto, Sugiura Sayoko, Tateyama Hidemi, Awakihara Syuji, Mitsutomi Yoshiro, Muraoka Masato, Tadokoro Kenji
Japanese Red Cross Tokyo Metropolitan West Blood Center, Tokyo, Japan.
Transfusion. 2009 Oct;49(10):2152-7. doi: 10.1111/j.1537-2995.2009.02243.x. Epub 2009 Jun 4.
Bacterial contamination of platelet concentrates (PCs) is the major infectious risk in transfusion medicine. To evaluate the necessity of implementing novel strategies for the reduction of bacterial contamination, it is necessary to establish a precise contamination frequency in PCs.
The frequency of bacterial contamination in PCs issued by the Japanese Red Cross was determined using expired PCs before and after the implementation of the diversion method. The culture method was designed such that it yields the least possibility of false-negative results: platelet specimens were sampled after at least 4 days of storage and the inoculum volume was 10 mL for both aerobic and anaerobic bottle cultures.
Of the 21,786 PCs cultured, 36 (0.17%) were confirmed to be bacterially contaminated before the implementation of the diversion method. After its implementation, the number of contaminated PCs decreased to 11 of 21,783 (0.05%) with a reduction rate of 71% and the number of contaminations of clinical importance was 4 (0.018%) excluding PCs positive for Propionibacterium acnes. The frequency of contamination by bacteria presumed to originate from donors' blood did not decrease.
The effect of the diversion method on the frequency of bacterial contamination is robust. The low incidence of septic reactions after PC transfusion in Japan in spite of the contamination frequency being comparable to those in Western countries and the noninstitution of culture screening suggests the importance of a short shelf life (72 hr) for PCs introduced in Japan.
血小板浓缩物（PCs）的细菌污染是输血医学中的主要感染风险。为评估实施减少细菌污染新策略的必要性，有必要确定PCs中精确的污染频率。
利用日本红十字会发放的过期PCs，在实施转移方法前后测定PCs的细菌污染频率。培养方法的设计旨在使假阴性结果的可能性最小：血小板标本在储存至少4天后取样，需氧和厌氧瓶培养的接种量均为10 mL。
在培养的21786份PCs中，实施转移方法前有36份（0.17%）被确认为细菌污染。实施后，污染的PCs数量降至21783份中的11份（0.05%），减少率为71%，排除痤疮丙酸杆菌阳性的PCs后，具有临床重要性的污染数量为4份（0.018%）。推测源自献血者血液的细菌污染频率并未降低。
转移方法对细菌污染频率的影响显著。尽管日本PCs的污染频率与西方国家相当，但日本PCs输血后败血症反应的发生率较低，且未进行培养筛查，这表明日本引入的PCs保质期较短（72小时）很重要。
