TABLE 2.

Performance of OptiMAL in detecting persistent blood-stage infections compared to standard light microscopy: tabulation of paired OptiMAL and microscopy results and assessment of the ability of OptiMAL to detect treatment failures

Microscopy result	OptiMAL result
	Day 2 (n = 223)				Day 7 (n = 235)				Day 14 (n = 240)
	P. falciparuma	Non- P. falciparumb	Negative	Performance (%)c	P. falciparum	Non- P. falciparum	Negative	Performance (%)	P. falciparum	Non- P. falciparum	Negative	Performance (%)
Asexual formsd
P. falciparum	21	9	32		5	0	2		2	0	7
Non-P. falciparum	1	3	3		2	1	2		2	1	1
Negative	48	15	91		44	6	173		13	5	209
OptiMAL performance
Sensitivity				49.3				66.7				38.5
Specificity				59.1				77.6				92.1
PPV				35.1				13.8				21.7
NPV				72.2				97.7				96.3

^aTest positive for P. falciparum-specific antigen. This indicates the presence of a P. falciparum or mixed P. falciparum/non-P. falciparum infection.

^bTest positive for panmalaria antigen but no P. falciparum-specific band visible. This is indicative of a non-P. falciparum infection but does not completely rule out the presence of low-level P. falciparum parasitemia.

^cEvaluated for positive (irrespective of species detected) versus negative results, as follows: sensitivity, TP/(TP + FN); specificity, TN/(FP + TN); PPV (positive predictive value), TP/(TP + FP); NPV (negative predictive value), TN/(TN + FN) (where TP is true positive, TN is true negative, FP is false positive, and FN is false negative).

^dAs the presence of asexual blood-stage parasites only indicates treatment failure, slides with gametocytes only were scored as negative.