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

Malaria Journal

Table 1 Comparison of malaria diagnostic methods (adapted from Mbanefo and Kumar 2020)

Method	Microscopy	RDT	PCR	LAMP	RPA (current assay)
Target	N/A	pHRP-2, LDH, Aldolase	18S rRNA	18S rRNA, Mitochondrial DNA	18S rRNA
Sensitivity	95%^a	85% to 94.8%	98% to 100	98.3% to 100%	95%^a
Specificity	98%^a	95.2% to 99%	88% to 94%	94.3% to 100%	88%^a
Limit of detection	50–200 parasites per μL	0–100 parasites per μL	0.5–5 parasites per μL	1–5 parasites per μL	1.7–16.7 parasites/µL
Cost per test	$0.12–$0.40	$0.85	$7–$8	< $1–$5.3	$2.5–3.5^b,c
Time	60 min	15–20 min	2 h	30-60 min	35–45 min

Comparisons are against microscopy unless specified. Time estimates do not include sample preparation (see Fig. 2)
^aSensitivity and specificity as compared to polymerase chain reaction (PCR)
^bRPA-LF costs are driven by the TwistAmp nfo kit (approx. $500 per 96 reaction pellets, which can be reconstituted and split for use with five 10 µL reactions each) and lateral flow strips (approx. $2 per unit). Other costs are comparable to PCR, though RPA does not require the up-front equipment costs (thermocycler). Precise estimates per reaction are expected to vary by location
^cFor economical use of resources, we have effectively reduce the reaction volume to 10 µL (comprising 9 µL master mix and a proportional 1 µL of DNA template). Manufacturer recommendations for Twist reagent storage is 4 °C for short periods and − 20 °C for longer periods

ISSN: 1475-2875