Kleinman Steven H, Williams Joan Dunn, Robertson Gene, Caglioti Sally, Williams Robert C, Spizman Randall, Morgan Larry, Tomasulo Peter, Busch Michael P
University of British Columbia, Vancouver, British Columbia, Canada.
Transfusion. 2009 Jun;49(6):1160-70. doi: 10.1111/j.1537-2995.2009.02127.x. Epub 2009 Mar 20.
In 2007, clients served by Blood Systems Laboratories used variable approaches for triggering West Nile virus (WNV) RNA individual-donation (ID) nucleic acid testing (NAT). These included two minipool (MP) NAT-reactive donations and a greater than 1:1000 rate in a 7-day interval (primary trigger), criteria based on one MP-NAT-reactive donation when there was WNV activity in overlapping and/or adjacent geographic areas (neighbor trigger), or zero MP-NAT-reactive donation (self-trigger).
The Procleix WNV assay was used in either a 16-sample MP or an ID format. NAT-repeat reactivity or anti-immunoglobulin M (IgM) positivity defined true positives (TPs). TPs that were negative on 1:16 dilution testing were considered ID-NAT yield cases.
WNV NAT performed on 1,217,929 donations identified 162 TPs; 87 were detected by MP (rate of 0.008%) and 75 by ID (rate of 0.10%; p < 0.0001). There were 34 ID-NAT yield cases, including 4 IgM/immunoglobulin G (IgG)-negative and 9 IgM-positive/IgG-negative donations. Rates of yield cases by primary, neighbor, and self-triggering were 0.077, 0.052, and 0.004% (p = 0.0003). None of 11 ID-NAT yield cases detected by the neighbor trigger would have been detected if the primary trigger had been used.
Primary triggering criteria identified 21 viremic donations that would have been missed by MP testing; however, 11 other low-level viremic donations required more stringent criteria (e.g., neighbor trigger) for detection. It is reasonable to adopt more stringent ID-NAT triggers, including elimination of the rate criterion and triggering on one NAT-reactive donation for regions adjacent to centers which have already triggered.
2007年，血液系统实验室的客户采用多种不同方法来启动西尼罗河病毒（WNV）RNA个体献血（ID）核酸检测（NAT）。这些方法包括两次小批量混合（MP）NAT反应性献血以及7天间隔内大于1:1000的比例（主要触发标准），当重叠和/或相邻地理区域存在WNV活动时基于一次MP-NAT反应性献血的标准（邻域触发标准），或零次MP-NAT反应性献血（自我触发标准）。
采用Procleix WNV检测法，以16样本MP或ID形式进行检测。NAT重复反应性或抗免疫球蛋白M（IgM）阳性定义为真阳性（TP）。在1:16稀释检测中呈阴性的TP被视为ID-NAT产出病例。
对1,217,929份献血进行的WNV NAT检测共识别出162例TP；87例通过MP检测发现（比例为0.008%），75例通过ID检测发现（比例为0.10%；p<0.0001）。有34例ID-NAT产出病例，包括4例IgM/免疫球蛋白G（IgG）阴性和9例IgM阳性/IgG阴性献血。主要触发标准、邻域触发标准和自我触发标准的产出病例比例分别为0.077%、0.052%和0.004%（p = 0.0003）。如果采用主要触发标准，邻域触发标准检测出的11例ID-NAT产出病例均不会被检测到。
主要触发标准识别出21例MP检测会遗漏的病毒血症献血；然而，另外11例低水平病毒血症献血需要更严格的标准（如邻域触发标准）来检测。采用更严格的ID-NAT触发标准是合理的，包括取消比例标准，并对已触发中心相邻区域基于一次NAT反应性献血进行触发。
