Azam Mudsser, Upmanyu Kirti, Gupta Ratan, Sruthy Karugatharayil Sasi, Matlani Monika, Savargaonkar Deepali, Singh Ruchi
Molecular Biology Laboratory, ICMR- National Institute of Pathology, New Delhi 110029, India.
Department of Paediatrics, VMMC and Safdarjung Hospital, New Delhi 110029, India.
Diagnostics (Basel). 2021 Sep 16;11(9):1689. doi: 10.3390/diagnostics11091689.
To strengthen malaria surveillance, field-appropriate diagnostics requiring limited technical resources are of critical significance. Loop-mediated isothermal amplification (LAMP) based malaria diagnostic assays are potential point-of-care tests with high sensitivity and specificity and have been used in low-resource settings. -specific consensus repeat sequence (CRS)-based and -specific 18S rRNA primers were designed, and a two-tube LAMP assay was developed. The diagnostic performance of a closed-tube LAMP assay and Loopamp™ Malaria Detection (Pan/Pf, Pv) kit was investigated using nested PCR confirmed mono- and co-infections of and positive ( = 149) and negative ( = 67) samples. The closed-tube Pv LAMP assay showed positive amplification in 40 min (limit of detection, LOD 0.7 parasites/µL) and Pf LAMP assay in 30 min (LOD 2 parasites/µL). Pv LAMP and Pf LAMP demonstrated a sensitivity and specificity of 100% (95% CI, 95.96-100% and 89.85-100%, respectively). The Loopamp Pan/Pf Malaria Detection kit demonstrated a sensitivity and specificity of 100%, whereas Loopamp Pv showed a sensitivity of 98.36% (95% CI, 91.28-99.71%) and specificity of 100% (95% CI, 87.54-100%). The developed two-tube LAMP assay is highly sensitive (LOD ≤ 2 parasite/µL), demonstrating comparable results with the commercial Loopamp™ Malaria Detection (Pf/pan) kit, and was superior in detecting the co-infection that remained undetected by the Loopamp™ Pv kit. The developed indigenous two-tube Pf/Pv malaria detection can reliably be used for mass screening in resource-limited areas endemic for both and malaria.
为加强疟疾监测,需要有限技术资源且适用于现场的诊断方法至关重要。基于环介导等温扩增(LAMP)的疟疾诊断检测是具有高灵敏度和特异性的潜在即时检测方法,已在资源匮乏地区使用。设计了基于特异性共有重复序列(CRS)和特异性18S rRNA引物,并开发了一种双管LAMP检测方法。使用巢式PCR确认的149份阳性和67份阴性样本的 单感染和混合感染,研究了闭管LAMP检测和Loopamp™疟疾检测(泛/恶性疟原虫、间日疟原虫)试剂盒的诊断性能。闭管间日疟原虫LAMP检测在40分钟内显示阳性扩增(检测限,LOD 0.7个寄生虫/微升),恶性疟原虫LAMP检测在30分钟内显示阳性扩增(LOD 2个寄生虫/微升)。间日疟原虫LAMP和恶性疟原虫LAMP的灵敏度和特异性分别为100%(95%置信区间,分别为95.96 - 100%和89.85 - 100%)。Loopamp泛/恶性疟原虫疟疾检测试剂盒的灵敏度和特异性为100%,而Loopamp间日疟原虫的灵敏度为98.36%(95%置信区间,91.28 - 99.71%),特异性为100%(95%置信区间,87.54 - 100%)。所开发的双管LAMP检测具有高度敏感性(LOD≤2个寄生虫/微升),与商业Loopamp™疟疾检测(恶性疟原虫/泛)试剂盒结果相当,并且在检测Loopamp™间日疟原虫试剂盒未检测到的混合感染方面更具优势。所开发的本土双管恶性疟原虫/间日疟原虫疟疾检测方法可可靠地用于 疟疾和 疟疾流行的资源有限地区的大规模筛查。