PDF(Pubmed)
Abstract：
South Africa\'s efforts toward eliminating malaria have positioned the country in the pre-elimination stage. Imported and sub-microscopic cases still contribute to the persistence of malaria in regions of low transmission as identified in this study where diagnostics is built largely on the use of Rapid Diagnostic Test (RDT). However, the presence of Pfhrp2/3 gene deletion is known to interfere with the accuracy of diagnosis with the use of RDT. Malaria elimination and detection of Pfhrp2/3 gene deletion in the pre-elimination setting requires accurate molecular surveillance. With the core objective of this study being the determination of the presence sub-microscopic malaria cases and deleted Pfhrp2/3 gene markers, a total of 354 samples were collected from five districts of KwaZulu Natal, South Africa. These samples were prepared for molecular analysis using primers and PCR conditions specific for amplification of 18S rRNA and msp-1gene. Positive amplicons were analysed for the presence of Pfhrp2/3 and flanking genes, along with Sanger sequencing and phylogenetic studies. Out of 354 samples collected 339 were tested negative with PfHRP2 based RDTs. Of these Pfhrp2 and Pfhrp3 gene deletions were confirmed in 94.7% (18/19) and 100% (19/19) respectively. High migration rate (75%) among the study participants was noted and phylogenetic analysis of sequenced isolates showed close evolutionary relatedness with India, United Kingdom, Iran, and Myanmar and China isolates. Molecular-based test is recommended as an essential surveillance tool for malaria management programs as the target focuses on elimination.
摘要：
南非为消除疟疾所做的努力使该国处于消除疟疾前阶段。进口和亚显微病例仍然有助于疟疾在低传播地区的持续存在，正如本研究中所确定的那样，诊断主要建立在使用快速诊断检测（RDT）的基础上。然而,已知Pfhrp2/3基因缺失的存在会干扰使用RDT的诊断准确性。在消除前设置中消除疟疾和检测Pfhrp2/3基因缺失需要准确的分子监测。这项研究的核心目标是确定亚显微疟疾病例和缺失的Pfhrp2/3基因标记，总共从夸祖鲁纳塔尔省的五个地区收集了354个样本，南非。使用引物和对18SrRNA和msp-1基因的扩增具有特异性的PCR条件制备这些样品用于分子分析。分析阳性扩增子是否存在Pfhrp2/3和侧翼基因，以及Sanger测序和系统发育研究。在收集的354个样品中,339个用基于PfHRP2的RDT测试为阴性。这些Pfhrp2和Pfhrp3基因缺失分别在94.7%(18/19)和100%(19/19)中得到证实。研究参与者中的高迁移率（75％）被注意到，测序分离株的系统发育分析表明与印度的进化亲缘关系密切，英国,伊朗,缅甸和中国孤立。建议将分子检测作为疟疾管理计划的基本监测工具，因为目标是消除疟疾。
