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Table 4 Evaluation of (a) QuantiFast™ and (b) abTES™ for P. knowlesi compared to other Plasmodium species

From: 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

  P. knowlesi P. vivax p-val
(Pk vs Pv)
P. falciparum p-val
(Pk vs Pf)
P. malariae p-val
(Pk vs Pm)
(a) QuantiFast™
 PCR reference + +   +   +  
 Test positive + 51 1 25 0   21 0   9 1*  
 Test negative − 1 81 0 109   0 113   0 124  
 Sensitivity,  % (95% CI) 98.1 (89.7, 100) 100 (86.3, 100) 0.49 100 (83.9, 100) 0.52 90.0 (55.5, 99.7) 0.20
 Specificity,  % (95% CI) 98.8 (93.4, 100) 100 (96.7, 100) 0.25 100 (96.8, 100) 0.24 100 (97.1, 100) 0.22
 ROC area, (95% CI) 0.98 (0.96, 1) 1 (1, 1) 0.15 1 (1, 1) 0.15 0.95 (0.85, 1) 0.57
 PPV,  % (95% CI) 98.1 (89.7, 100) 100 (86.3, 100) 0.49 100 (83.9, 100) 0.52 100 (66.4, 100) 0.68
 NPV,  % (95% CI) 98.8 (93.4, 100) 100 (96.7, 100) 0.25 100 (96.8, 100) 0.24 99.2 (95.6, 100) 0.77
(b) abTES™
 PCR reference + +   +   +  
 Test positive + 52 0 25 0   21 0   10 0  
 Test negative − 1 81 0 109   0 113   0 124  
 Sensitivity,  % (95% CI) 100 (93.2, 100) 100 (86.3, 100) 1.0 100 (83.9, 100) 1.0 100 (69.2, 100) 1.0
 Specificity,  % (95% CI) 98.8 (93.4, 100) 100 (96.7, 100) 0.25 100 (96.8, 100) 0.24 100 (97.1, 100) 0.22
 ROC area, (95% CI) 0.99 (0.98, 1) 1 (1, 1) 0.31 1 (1, 1) 0.31 1 (1, 1) 0.31
 PPV,  % (95% CI) 98.1 (89.9, 100) 100 (86.3, 100) 0.49 100 (83.9, 100) 0.52 100 (69.2, 100) 0.66
 NPV,  % (95% CI) 100 (95.5, 100) 100 (96.7, 100) 1.0 100 (96.8, 100) 1.0 100 (97.1, 100) 1.0
  1. *Includes a mixed P. malariae/P. knowlesi result which was false negative for a P. malariae monoinfection on reference PCR