Screening for Babesia microti in the U. S. Blood Supply
Screening for Babesia microti in the U. S. Blood Supply
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DOI：
10.1056/nejmoa1600897
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发表时间：
2016-12-08
影响因子：
158.5
通讯作者：
Stramer, Susan L.
中科院分区：
文献类型：
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作者：
Moritz, Erin D.;Winton, Colleen S.;Stramer, Susan L.
背景 微小巴贝虫是一种蜱传红细胞内寄生虫，可通过输血传播，是美国大多数输血传播巴贝虫病病例的罪魁祸首。然而，尚无获得许可的测试可用于筛查捐献血液中的田鼠芽孢杆菌。我们评估了大规模研究性产品发布筛选和供体随访计划的数据。 方法 从 2012 年 6 月到 2014 年 9 月，我们对康涅狄格州、马萨诸塞州、明尼苏达州和威斯康星州获得的献血样本进行了田鼠芽孢杆菌抗体的阵列荧光免疫测定 (AFIA) 和田鼠芽孢杆菌 DNA 的实时聚合酶链反应 (PCR) 测定。我们通过定量 PCR 检测确定寄生虫载量，并通过仓鼠接种和随后的寄生虫血症检查评估感染性。对携带测试反应样本的捐赠者进行了跟踪。利用输血传播巴贝西虫病病例的数据，我们比较了经过筛查和未经筛查的献血者具有传染性的比例。 结果 在检测的 89,153 份献血样本中，335 份（0.38%）被确认为阳性，其中 67 份（20%）为 PCR 阳性； 9 个样本呈抗体阴性（即每 9906 个筛查样本中有 1 个抗体阴性样本），占所有 PCR 阳性样本的 13%。全年均发现PCR阳性样本；抗体阴性感染发生在六月至九月期间。来自 PCR 阳性或高滴度 AFIA 阳性捐赠仓鼠的红细胞样本中大约有三分之一受到感染。随访显示 1 年后，86% 的捐献者 DNA 被清除，但 8% 的抗体血清逆转。在康涅狄格州和马萨诸塞州，没有报告的输血传播巴贝西虫病病例与筛查捐赠有关（即每 75,331 份筛查捐赠中 0 例），而每 253,031 份未经筛查捐赠中有 14 例（即每 18,074 份未经筛查捐赠 1 例）（比值比，8.6；95% 置信区间， 0.51 至 144；P = 0.05)。总体而言，29 例输血传播巴贝虫病与受感染献血者的血液有关，其中包括 10 名献血者的血液，这些献血者在献血后 2 至 7 个月的 PCR 检测结果呈阳性。 结论 献血筛查田鼠巴贝虫病抗体和 DNA 与输血传播巴贝虫病风险降低相关。 （由美国红十字会和 Imugen 资助；ClinicalTrials.gov 编号，NCT01528449。）
BACKGROUND Babesia microti, a tickborne intraerythrocytic parasite that can be transmitted by means of blood transfusion, is responsible for the majority of cases of transfusiontransmitted babesiosis in the United States. However, no licensed test exists for screening for B. microti in donated blood. We assessed data from a large-scale, investigational product-release screening and donor follow-up program.METHODS From June 2012 through September 2014, we performed arrayed fluorescence immunoassays (AFIAs) for B. microti antibodies and real-time polymerase-chain-reaction (PCR) assays for B. microti DNA on blood-donation samples obtained in Connecticut, Massachusetts, Minnesota, and Wisconsin. We determined parasite loads with the use of quantitative PCR testing and assessed infectivity by means of the inoculation of hamsters and the subsequent examination for parasitemia. Donors with test-reactive samples were followed. Using data on cases of transfusiontransmitted babesiosis, we compared the proportions of screened versus unscreened donations that were infectious.RESULTS Of 89,153 blood-donation samples tested, 335 (0.38%) were confirmed to be positive, of which 67 (20%) were PCR-positive; 9 samples were antibody-negative (i.e., 1 antibody-negative sample per 9906 screened samples), representing 13% of all PCR-positive samples. PCR-positive samples were identified all through the year; antibody-negative infections occurred from June through September. Approximately one third of the red-cell samples from PCR-positive or high-titer AFIA-positive donations infected hamsters. Follow-up showed DNA clearance in 86% of the donors but antibody seroreversion in 8% after 1 year. In Connecticut and Massachusetts, no reported cases of transfusion-transmitted babesiosis were associated with screened donations (i.e., 0 cases per 75,331 screened donations), as compared with 14 cases per 253,031 unscreened donations (i.e., 1 case per 18,074 unscreened donations) (odds ratio, 8.6; 95% confidence interval, 0.51 to 144; P = 0.05). Overall, 29 cases of transfusion-transmitted babesiosis were linked to blood from infected donors, including blood obtained from 10 donors whose samples tested positive on the PCR assay 2 to 7 months after the implicated donation.CONCLUSIONS Blood-donation screening for antibodies to and DNA from B. microti was associated with a decrease in the risk of transfusion-transmitted babesiosis. (Funded by the American Red Cross and Imugen; ClinicalTrials. gov number, NCT01528449.)