National Centre of Tropical Medicine, Institute of Health Carlos III, Malaria and Neglected Tropical Diseases Laboratory, Madrid, Spain.
Cooperative Research Network on Tropical Diseases (Red de Investigación Colaborativa en Enfermedades Tropicales), Madrid, Spain.
Mem Inst Oswaldo Cruz. 2022 Feb 11;116:e210210. doi: 10.1590/0074-02760210210. eCollection 2022.
Loa loa is a filarial species found exclusively in West and Central Africa. Microscopy is the traditional diagnosis method for human loiasis. Several molecular methods have developed as an alternative approach for identification of L. loa filarial parasites.
The aim of this study was to evaluate a Loa-Loop-mediated isothermal amplification (LAMP) assay to diagnose loiasis disease on dried blood spots (DBS) samples, compared to microscopy, filaria-real time-polymerase chain reaction (PCR) and nested-Loa PCR.
A total of 100 DBS samples and 100 blood smears were used for this study. DNA was extracted using saponin/Chelex method. DNA isolated was assayed by a Loa-LAMP assay in parallel to microscopy, filaria-real time PCR and nested-Loa PCR. The sensitivities and specificities of Loa-LAMP assay was computed comparing to each one of the reference methods.
Loa-LAMP's sensitivity was more than 90% and specificity was nearly 100% when compared to molecular methods. On the other hand, sensitivity was decreased a bit when Loa-LAMP faced microscopy, but keeping the other statistical values high.
Loa-LAMP is an appropriate method for loiasis diagnosis in endemic areas. Though, it has disadvantages like the reagents' high price at the moment and not to be able to detect more filarial species at once.
罗阿丝虫是一种仅存在于西非和中非的丝状虫。显微镜检查是人类罗阿丝虫病的传统诊断方法。已经开发出几种分子方法作为鉴定罗阿丝虫丝状寄生虫的替代方法。
本研究旨在评估一种基于环介导等温扩增（LAMP）的检测方法，用于诊断干血斑（DBS）样本中的罗阿丝虫病，与显微镜检查、丝虫实时聚合酶链反应（PCR）和巢式罗阿 PCR 进行比较。
本研究共使用了 100 份 DBS 样本和 100 份血涂片。使用皂素/Chelex 法提取 DNA。使用 LAMP 检测试剂盒平行检测 DNA，同时与显微镜检查、丝虫实时 PCR 和巢式罗阿 PCR 进行比较。将 LAMP 检测的灵敏度和特异性与每种参考方法进行比较。
与分子方法相比，Loa-LAMP 的灵敏度超过 90%，特异性接近 100%。另一方面，当 LAMP 检测面对显微镜检查时，灵敏度略有下降，但其他统计值仍保持较高水平。
Loa-LAMP 是疫区罗阿丝虫病诊断的一种合适方法。尽管如此，它存在一些缺点，例如目前试剂价格较高，并且不能同时检测更多的丝虫种类。
