Comparative evaluation of two commercial real-time PCR kits (QuantiFast™ and abTES™) for the detection of Plasmodium knowlesi and other Plasmodium species in Sabah, Malaysia

Table 2 Patient demographic details, clinical data, and diagnostic accuracy of screening hospital microscopy

Species (no. of patients tested), or parameter	P. knowlesi (52)	P. vivax (25)	P. falciparum (21)	P. malariae (10)	Negative controls (26)	p-value
Age, median years (range)	35 (25, 47)	18 (9, 34)	16 (10, 39)	14 (7, 23)	44 (22, 76)	< 0.001^a
Sex, n male (%)	43 (83)	18 (72)	20 (95)	7 (70)	12 (46)	0.001
Parasitaemia, geometric mean parasites/µL, (95% CI), [range]	9435 (7320–12,161) [138–35,873]	9411 (7004–12,645) [625–36,248]	24,631 (14,406–42,115) [1074–297,000]	1023 (586–1787) [224–3056]	–	< 0.001^b
Hospital microscopy^c
Sensitivity^d, TP/TP + FN; % (95% CI)	41/52; 78.8 (65.3, 88.9)	23/25; 92.0 (74.0, 99.0)	17/21; 81.0 (58.1, 94.6)	0/10; 0 (0, 30.8)	–	< 0.001
Specificity, TN/TN + FP; % (95% CI)	45/56; 80.4 (67.6, 89.8)	83/83; 100 (95.7, 100)	86/87; 98.9 (93.8, 100)	87/98; 88.8 (80.8, 94.3)	–	< 0.001

^aP. knowlesi compared to: P. vivax (t = 3.3, df = 39, p = 0.002); P. falciparum (t = 2.6, df = 29, p = 0.02); P. malariae (t = 4.8, df = 15, p < 0.001); P. knowlesi against negative controls (t = 2.1, df = 54, p = 0.04)
^bP. knowlesi compared to: P. vivax (t = 0.1, df = 59, p = 0.99); P. falciparum (t = 3.3, df = 30, p = 0.002); P. malariae (t = 8.0, df = 14, p < 0.001)
^cHospital microscopy compared against reference PCR
^d2 P. vivax monoinfections misidentified as P. knowlesi; 4 P. falciparum infections misidentified as mixed P. knowlesi/P. falciparum; 10 P. malariae infections misidentified as P. knowlesi

ISSN: 1475-2875