TABLE 2.

Results for four assays for diagnosis of S. stercoralis

Test	Cutoffa	% Sensitivity	% Specificity	Predictive valueb at disease prevalence (%)
				50		20		3		1		0.1		0.001
				PPV	NPV	PPV	NPV	PPV	NPV	PPV	NPV	PPV	NPV	PPV	NPV
CrAg-ELISA	1.7 U/ml−1	97	100	100	97.09	100	99.26	100	99.91	100	99.97	100	100	100	100
NIE-ELISA	119.04 U/ml−1	84	100	100	85.84	100	96.04	100	99.49	100	99.83	100	99.98	100	100
NIE-LIPS	37.89 LU	97.8	100	100	97.85	100	99.45	100	99.93	100	99.98	100	100	100	100
NIE-SsIR-LIPS	1199 LU	91.2	100	100	91.91	100	97.85	100	99.73	100	99.91	100	99.99	100	100

^aCutoffs for NIE-LIPS, NIE-ELISA, NIE-SsIR-LIPS assays with corresponding sensitivity and specificity as calculated by ROC curve analysis. The cutoff for the CrAg-ELISA has been previously determined and was not determined by our analysis.

^bCalculated positive and negative predictive values (PPV and NPV, respectively) at a variety of prevalence levels based on the selected cutoff values.