Department of Medical Microbiology, College of Health Sciences, Jomo Kenyatta University of Agriculture and Technology, P. O. Box 62000-00200, Nairobi, Kenya.
Kenya Medical Research Institute, Centre for Global Health Research, P. O. Box 1578-40100, Kisumu, Kenya.
Malar J. 2020 Sep 9;19(1):329. doi: 10.1186/s12936-020-03397-0.
Prompt diagnosis and effective malaria treatment is a key strategy in malaria control. However, the recommended diagnostic methods, microscopy and rapid diagnostic tests (RDTs), are not supported by robust quality assurance systems in endemic areas. This study compared the performance of routine RDTs and smear microscopy with a simple molecular-based colorimetric loop-mediated isothermal amplification (LAMP) at two different levels of the health care system in a malaria-endemic area of western Kenya.
Patients presenting with clinical symptoms of malaria at Rota Dispensary (level 2) and Siaya County Referral Hospital (level 4) were enrolled into the study after obtaining written informed consent. Capillary blood was collected to test for malaria by RDT and microscopy at the dispensary and county hospital, and for preparation of blood smears and dried blood spots (DBS) for expert microscopy and real-time polymerase chain reaction (RT-PCR). Results of the routine diagnostic tests were compared with those of malachite green loop-mediated isothermal amplification (MG-LAMP) performed at the two facilities.
A total of 264 participants were enrolled into the study. At the dispensary level, the positivity rate by RDT, expert microscopy, MG-LAMP and RT-PCR was 37%, 30%, 44% and 42%, respectively, and 42%, 43%, 57% and 43% at the county hospital. Using RT-PCR as the reference test, the sensitivity of RDT and MG-LAMP was 78.1% (CI 67.5-86.4) and 82.9% (CI 73.0-90.3) at Rota dispensary. At Siaya hospital the sensitivity of routine microscopy and MG-LAMP was 83.3% (CI 65.3-94.4) and 93.3% (CI 77.9-99.2), respectively. Compared to MG-LAMP, there were 14 false positives and 29 false negatives by RDT at Rota dispensary and 3 false positives and 13 false negatives by routine microscopy at Siaya Hospital.
MG-LAMP is more sensitive than RDTs and microscopy in the detection of malaria parasites at public health facilities and might be a useful quality control tool in resource-limited settings.
快速诊断和有效治疗疟疾是疟疾控制的关键策略。然而，在流行地区，推荐的诊断方法，即显微镜检查和快速诊断检测（RDT），并未得到稳健的质量保证系统的支持。本研究在肯尼亚西部疟疾流行地区的两个不同的医疗保健系统级别比较了常规 RDT 和涂片显微镜检查与简单的基于分子的比色环介导的等温扩增（LAMP）的性能。
在获得书面知情同意后，在罗塔诊所（二级）和锡亚县转诊医院（四级）就诊的具有疟疾临床症状的患者被纳入研究。采集毛细血管血，在诊所和县级医院进行 RDT 和显微镜检查以检测疟疾，并制备血涂片和干血斑（DBS）以进行专家显微镜检查和实时聚合酶链反应（RT-PCR）。将常规诊断测试的结果与在两个设施进行的孔雀石绿环介导等温扩增（MG-LAMP）的结果进行比较。
共纳入 264 名参与者。在诊所级别，RDT、专家显微镜检查、MG-LAMP 和 RT-PCR 的阳性率分别为 37%、30%、44%和 42%，在县级医院则分别为 42%、43%、57%和 43%。以 RT-PCR 为参考测试，RDT 和 MG-LAMP 在罗塔诊所的灵敏度分别为 78.1%（67.5-86.4）和 82.9%（73.0-90.3）。在 Siaya 医院，常规显微镜检查和 MG-LAMP 的灵敏度分别为 83.3%（65.3-94.4）和 93.3%（77.9-99.2）。与 MG-LAMP 相比，在罗塔诊所，RDT 有 14 个假阳性和 29 个假阴性，在 Siaya 医院，常规显微镜检查有 3 个假阳性和 13 个假阴性。
在公共卫生设施中，MG-LAMP 比 RDTs 和显微镜检查更灵敏，可能是资源有限环境中的有用质量控制工具。
