Applicability of B2t, E14t, and C317 recombinant proteins for the diagnosis of UHD by IgG ELISA compared to that of HF with a panel of defined sera. (a) Number of positive and negative (+/−) sera against HF, B2t, E14t, and C317 antigens. (b) ROC curves used to determine AUC and cutoff values for the HF, B2t, E14t, and C317 antigens. (c) The calculated AUCs ± standard errors (se), confidence intervals (CI), cutoffs, sensitivity, and specificity for each antigen are shown. Positive and negative predictive values (PPV and NPV, respectively) also are shown.