Table 3.

Results of receiver operating chraracteristics (ROC) analysis

ELISA Kit	Optimized ELISA cut-off	AUC (95% CI)	% Relative sensitivity (95% CI)	% Relative specificity (95% CI)	PPV % (95% CI)	NPV % (95% CI)
TOXO-MS	≥ 36.2 S/P%	0.97 (0.94–1.00)	94.5 (87.6–98.2)	97.9 (92.6–99.7)	97.7 (92.0–99.3)	94.9 (88.5–99.4)
NCS-MS	≥ 34.9 S/P%	0.96 (0.91–1.01)	89.3 (71.8–97.7)	100.0 (95.4–NaN)	100 (86.9–100)	96.3 (88.8–NaN)
NCC	≤ 78.6 S/N%	0.97 (0.92–1.01)	92.9 (76.5–99.1)	97.4 (91.0–99.7)	92.9 (77.7–99.1)	97.4 (90.5–99.7)

Notes: Relative accuracies of commercial ELISA kits used for detection of antibodies against Toxoplasma gondii (i.e. ID Screen® Toxoplasmosis Indirect ELISA) and N. caninum (i.e. ID Screen® Neospora caninum Indirect Multi-species ELISA and ID Screen® Neospora caninum Competition ELISA) in South American camelids, in relation to N. caninum and T. gondii immunoblots

Abbreviations: TOXO-MS, ID Screen® Toxoplasmosis Indirect; NCS-MS, ID Screen® Neospora caninum Indirect Multi-species ELISA; NCC, ID Screen® Neospora caninum Competition; S/P%, sample-to-positive ratio; S/N%, competition percentage; AUC, area under the ROC curve; CI, confidence interval; TP, true positives; FP, false positives; TN, true negatives; FN, false negatives; PPV, positive predictive value; NPV, negative predictive value; NaN, upper limit of the confidence interval could not be computed