Detection of P. malariae using a new rapid isothermal amplification lateral flow assay.

P. malariae is found worldwide and causes chronic parasitism in its human hosts. We developed a P. malariae (Pm) diagnostic assay that uses rapid, isothermal recombinase polymerase amplification (RPA) and lateral-flow-strip detection. Using 18S rRNA plasmid DNA, the assay demonstrates a detection limit of 10 copies /µL (~1.7 genome equivalents) and 100% analytical specificity. Testing in field samples showed 95% clinical sensitivity and 88% specificity compared to qPCR. Total assay time was 35 minutes. Combined with simplified DNA extraction methods, the assay has potential for future field-deployable point-of-care use to detect a parasite species that remains largely undiagnosed.