Malaria, Centre for Disease Control, Malaria, Schistosomiasis and Leishmaniasis Control Program, State Ministry of Health, Nyala, Sudan.
Department of Biology, Faculty of Exact and Applied Sciences, University of N'djamena, N'djamena, Chad.
Sci Rep. 2020 Jul 30;10(1):12822. doi: 10.1038/s41598-020-69756-8.
In remote areas of malaria-endemic countries, rapid diagnostic tests (RDTs) have dramatically improved parasitological confirmation of suspected malaria cases, especially when skilled microscopists are not available. This study was designed to determine the frequency of Plasmodium falciparum isolates with histidine-rich protein 2 (pfhrp2) gene deletion as one of the possible factors contributing to the failure of PfHRP2-based RDTs in detecting malaria. A total of 300 blood samples were collected from several health centres in Nyala City, Western Sudan. The performance of PfHRP2-based RDTs in relation to microscopy was examined and the PCR-confirmed samples were investigated for the presence of pfhrp2 gene. A total of 113 out of 300 patients were P. falciparum positive by microscopy. Among them, 93.81% (106 out of 113) were positives by the PfHRP2 RDTs. Seven isolates were identified as false negative on the basis of the RDTs results. Only one isolate (0.9%; 1/113) potentially has pfhrp2 gene deletion. The sensitivity and specificity of PfHRP2-based RDTs were 93.81% and 100%, respectively. The results provide insights into the pfhrp2 gene deletion amongst P. falciparum population from Sudan. However, further studies with a large and systematic collection from different geographical settings across the country are needed.
在疟疾流行国家的偏远地区，快速诊断检测（RDT）显著提高了疑似疟疾病例的寄生虫学确认率，尤其是在缺乏熟练显微镜检人员的情况下。本研究旨在确定裂殖体表面蛋白 2（PfHRP2）基因缺失的恶性疟原虫分离株的频率，这可能是 PfHRP2 为基础的 RDT 检测失败的原因之一。共从苏丹西部尼亚拉市的几个医疗中心采集了 300 份血样。检测了 PfHRP2 为基础的 RDT 与显微镜检查的相关性，并对 PCR 确认的样本进行了 pfhrp2 基因检测。通过显微镜检查，300 名患者中有 113 名被确认为恶性疟原虫阳性。其中，93.81%（106 例）通过 PfHRP2 RDT 检测为阳性。根据 RDT 结果，有 7 个分离株被鉴定为假阴性。仅有 1 个分离株（0.9%，1/113）可能存在 pfhrp2 基因缺失。PfHRP2 为基础的 RDT 的灵敏度和特异性分别为 93.81%和 100%。研究结果为了解苏丹恶性疟原虫群体中的 pfhrp2 基因缺失提供了思路。然而，需要在全国不同地理环境中进行更大规模和系统的采集，开展进一步的研究。
