Laboratory evaluation of the miniature direct-on-blood PCR nucleic acid lateral flow immunoassay (mini-dbPCR-NALFIA), a simplified molecular diagnostic test for Plasmodium
Abstract Background Point-of-care diagnosis of malaria is currently based on microscopy and rapid diagnostic tests. However, both techniques have their constraints, including poor sensitivity for low parasitaemias. Hence, more accurate diagnostic tests for field use and routine clinical settings are...
| Published in: | Malaria Journal |
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| Main Authors: | , , , , , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
BMC
2023
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| Subjects: | |
| Online Access: | https://doi.org/10.1186/s12936-023-04496-4 https://doaj.org/article/ee8f2800d2da4f1d9daa26c57f3d5c36 |
| Summary: | Abstract Background Point-of-care diagnosis of malaria is currently based on microscopy and rapid diagnostic tests. However, both techniques have their constraints, including poor sensitivity for low parasitaemias. Hence, more accurate diagnostic tests for field use and routine clinical settings are warranted. The miniature direct-on-blood PCR nucleic acid lateral flow immunoassay (mini-dbPCR-NALFIA) is an innovative, easy-to-use molecular assay for diagnosis of malaria in resource-limited settings. Unlike traditional molecular methods, mini-dbPCR-NALFIA does not require DNA extraction and makes use of a handheld, portable thermal cycler that can run on a solar-charged power pack. Result read-out is done using a rapid lateral flow strip enabling differentiation of Plasmodium falciparum and non-falciparum malaria infections. A laboratory evaluation was performed to assess the performance of the mini-dbPCR-NALFIA for diagnosis of pan-Plasmodium and P. falciparum infections in whole blood. Methods Diagnostic accuracy of the mini-dbPCR-NALFIA was determined by testing a set of Plasmodium-positive blood samples from returned travellers (n = 29), and Plasmodium-negative blood samples from travellers with suspected malaria (n = 23), the Dutch Blood Bank (n = 19) and intensive care patients at the Amsterdam University Medical Centers (n = 16). Alethia Malaria (LAMP) with microscopy for species differentiation were used as reference. Limit of detection for P. falciparum was determined by 23 measurements of a dilution series of a P. falciparum culture. A fixed sample set was tested three times by the same operator to evaluate the repeatability, and once by five different operators to assess the reproducibility. Results Overall sensitivity and specificity of the mini-dbPCR-NALFIA were 96.6% (95% CI, 82.2%–99.9%) and 98.3% (95% CI, 90.8%–100%). Limit of detection for P. falciparum was 10 parasites per microlitre of blood. The repeatability of the assay was 93.7% (95% CI, 89.5%–97.8%) and reproducibility was 84.6% (95% CI, ... |
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