Development of novel diagnostics for African non-falciparum malaria

非洲非恶性疟疾新型诊断方法的开发

• 批准号: 10057106
• 负责人: Jessica Lin
• 金额: $ 18.94万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-06-30 至 2022-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10057106
• 关键词: Address; Affect; Africa; Africa South of the Sahara; African; Antigens; Archives; Bedside Testings; Benchmarking; Biological Assay; Blood; Care Technology Points; Cause of Death; Cessation of life; Characteristics; Clinical; Clinical Sensitivity; Clustered Regularly Interspaced Short Palindromic Repeats; Country; Democratic Republic of the Congo; Dengue Virus; Detection; Development; Devices; Diagnosis; Diagnostic; Diagnostic tests; Drops; Epidemiology; Evaluation; Falciparum Malaria; Fingers; Fluorescence; Generations; HRP-2 protein; Human; Infection; Laboratories; Lactate Dehydrogenase; Lateral; Malaria; Methodology; Methods; Modernization; Mutation; Nucleic Acids; Parasites; Pathogen detection; Performance; Plasmodium; Plasmodium falciparum; Plasmodium malariae; Plasmodium ovale; Plasmodium vivax; Polymerase; Prevalence; Reaction; Reporter; Reporting; Research Personnel; Resources; Ribonucleases; Sampling; Sensitivity and Specificity; Signal Transduction; Site; Tanzania; Technology; Testing; Therapeutic; Time; Training; Translating; Work; World Health Organization; amplification detection; base; cost; density; experience; field study; handheld equipment; improved; malaria infection; mortality; multiplex detection; mutant; new technology; next generation; novel; novel diagnostics; nucleic acid detection; pathogen; point of care; programs; recombinase; trend

PROJECT SUMMARY While malaria deaths in Africa due to Plasmodium falciparum have fallen over the last decade, the proportion of malaria cases due to non-falciparum species is rising. Improved diagnostics are needed to respond to this changing epidemiology. Yet current “test and treat” strategies in Africa rely upon rapid diagnostic tests (RDTs) that do not reliably detect most non-falciparum infections and may be compromised by histidine-rich protein 2- (PfHRP2-) negative parasites. We propose to develop and compare novel recombinase polymerase amplification- (RPA-) and CRISPR-based diagnostic platforms that have the potential to launch the next generation of RDTs, capable of sensitive multiplexed detection of all Plasmodium species. We have already successfully adapted RPA and a new technology called SHERLOCK (Specific High Sensitivity Enzymatic Reporter Unlocking) for malaria, reaching limits of detection on par with real-time PCR. We now propose to tackle the more difficult detection of Plasmodium malariae and Plasmodium ovale. Our experience in diagnostic development and evaluation, expertise in non-falciparum and low-density malaria infections, and collaborative relationship with multiple in-country African investigators make us uniquely suited to pioneer this new technology. In Aim 1, we will develop and optimize P. malariae and P. ovale RPA and SHERLOCK assays with enhanced sensitivity and robustness, utilizing a range of strategies that have previously allowed streamlined, multiplexed detection of multiple pathogens. We will detect target nucleic acids using a multiplexed lateral flow device for RPA and simple fluorimeter for SHERLOCK. Sensitivity and specificity of the new assays will be benchmarked using a large sample bank of archived isolates from the Democratic Republic of the Congo and Tanzania. In Aim 2, we will field test the best performing RPA or SHERLOCK assays in Bagamoyo, Tanzania. We will determine their sensitivity and compare their performance to current RDTs, as well as real-time PCR. These studies will leverage promising new technology for pathogen detection to provide a low-cost platform for the study of non-falciparum malaria in low-resource settings. If successful, they will lay the groundwork for development of species-specific, sensitive RDTs capable of multiplexed detection of both P. falciparum and non-falciparum malaria in Africa.

项目摘要 虽然非洲因恶性疟原虫导致的疟疾死亡人数在过去十年中有所下降，但这一比例 由非恶性疟原虫物种引起的疟疾病例正在增加。需要改进诊断以应对这一问题 改变流行病学然而，非洲目前的“检测和治疗”战略依赖于快速诊断检测 （RDTs）不能可靠地检测大多数非恶性疟原虫感染，并且可能受到富含组氨酸的 蛋白2-（PfHRP 2-）阴性寄生虫。我们建议开发和比较新型重组酶聚合酶 基于扩增（RPA）和CRISPR的诊断平台，有可能推出下一个 生成RDT，能够灵敏地多重检测所有疟原虫物种。我们已经 成功地采用了RPA和称为SHERMOND（特异性高灵敏度酶促 Reporter Unlocking），达到与实时PCR相当的检测极限。我们现建议 解决更难检测的三日疟原虫和卵形疟原虫。的经验 诊断发展和评价，非恶性疟和低密度疟疾感染方面的专门知识， 与多个非洲国内调查人员的合作关系使我们成为这方面的独特先驱 新技术目标一：开发和优化三日疟原虫和卵形疟原虫RPA和SHERRIPs 具有增强的灵敏度和鲁棒性的检测，利用一系列先前允许的策略， 对多种病原体进行简化的多重检测。我们将使用 多路侧向流动装置用于RPA和简单荧光计用于SHERTM。敏感性和特异性 新的检测方法将使用来自民主党的大量存档分离物样本库进行基准测试。 刚果共和国和坦桑尼亚。在目标2中，我们将现场测试性能最佳的RPA或SHERERCITY 在坦桑尼亚的巴加莫约进行的试验。我们将确定它们的灵敏度，并将它们的性能与当前的 RDT和实时PCR。这些研究将利用有前途的新技术， 该项目的目的是提供一个低成本的平台，用于在资源匮乏的环境中研究非恶性疟疾。如果 如果成功，它们将为开发物种特异性、敏感性RDT奠定基础， 多重检测非洲的恶性疟原虫和非恶性疟原虫疟疾。