BACKGROUND The World Health Organization (WHO) recommends parasite-based diagnosis of malaria. In recent years, there has been surge in the use of various kinds of nucleic-acid amplification based tests (NAATs) for detection and identification of Plasmodium spp. to support clinical care in high-resource settings and clinical and epidemiological research worldwide. However, these tests are not without challenges, including lack (or limited use) of standards and lack of reproducibility, due in part to variation in protocols amongst laboratories. Therefore, there is a need for rigorous quality control, including a robust external quality assessment (EQA) scheme targeted towards malaria NAATs. To this effect, the WHO Global Malaria Programme worked with the UK National External Quality Assessment Scheme (UK NEQAS) Parasitology and with technical experts to launch a global NAAT EQA scheme in January 2017. METHODS Panels of NAAT EQA specimens containing five major species of human-infecting Plasmodium at various parasite concentrations and negative samples were created in lyophilized blood (LB) and dried blood spot (DBS) formats. Two distributions per year were sent, containing five LB and five DBS specimens. Samples were tested and validated by six expert referee laboratories prior to distribution. Between 37 and 45 laboratories participated in each distribution and submitted results using the online submission portal of UK NEQAS. Participants were scored based on their laboratory's stated capacity to identify Plasmodium species, and individual laboratory reports were sent which included performance comparison with anonymized peers. RESULTS Analysis of the first three distributions revealed that the factors that most significantly affected performance were sample format (DBS vs LB), species and parasite density, while laboratory location and the reported methodology used (type of nucleic acid extraction, amplification, or DNA vs RNA target) did not significantly affect performance. Referee laboratories performed better than non-referee laboratories. CONCLUSIONS Globally, malaria NAAT assays now inform a range of clinical, epidemiological and research investigations. EQA schemes offer a way for laboratories to assess and improve their performance, which is critical to safeguarding the reliability of data and diagnoses especially in situations where various NAAT methodologies and protocols are in use.

中文翻译：

---

WHO疟疾核酸扩增试验外部质量评估方案：结果分配方案一至三。


背景世界卫生组织（WHO）推荐基于寄生虫的疟疾诊断。近年来，各种基于核酸扩增的测试（NAAT）用于检测和鉴定疟原虫属的使用激增。支持资源丰富的环境中的临床护理以及全世界的临床和流行病学研究。然而，这些测试并非没有挑战，包括缺乏（或有限使用）标准和缺乏可重复性，部分原因是实验室之间协议的差异。因此，需要严格的质量控制，包括针对疟疾 NAAT 的强有力的外部质量评估 (EQA) 计划。为此，世卫组织全球疟疾规划与英国国家外部质量评估计划（UK NEQAS）寄生虫学及技术专家合作，于 2017 年 1 月启动了全球 NAAT EQA 计划。 方法 包含人类五种主要物种的 NAAT EQA 标本组-以冻干血（LB）和干血斑（DBS）形式制备不同寄生虫浓度的感染疟原虫和阴性样品。每年发送两次，包含 5 个 LB 样本和 5 个 DBS 样本。样品在分发前经过六个专家评审实验室的测试和验证。 37 至 45 个实验室参与了每次分发，并使用 UK NEQAS 在线提交门户提交了结果。根据实验室声称的识别疟原虫种类的能力对参与者进行评分，并发送个人实验室报告，其中包括与匿名同行的性能比较。 结果 对前三个分布的分析表明，对性能影响最显着的因素是样本格式（DBS 与 LB）、物种和寄生虫密度，而实验室位置和所报告的使用方法（核酸提取、扩增或 DNA 的类型与RNA 目标）不会显着影响性能。裁判实验室的表现优于非裁判实验室。结论 在全球范围内，疟疾 NAAT 检测现已为一系列临床、流行病学和研究调查提供信息。 EQA 方案为实验室提供了一种评估和提高其性能的方法，这对于保障数据和诊断的可靠性至关重要，尤其是在使用各种 NAAT 方法和协议的情况下。