Table 5. Sensitivity and specificity of EZtargex for the differentiation of middle or strong positivity at different cutoff values.

Cutoff Ct value	Sensitivity	95% CI	Specificity	95% CI
< 25.09	86.00	73.26%–94.18%	80.00	67.67%–89.22%
< 25.14	88.00	75.69%–95.47%	80.00	67.67%–89.22%
< 25.18	90.00	78.19%–96.67%	80.00	67.67%–89.22%
< 25.23	90.00	78.19%–96.67%	78.33	65.80%–87.93%
< 25.42	92.00	80.77%–97.78%	78.33	65.80%–87.93%
< 25.69	92.00	80.77%–97.78%	76.67	63.96%–86.62%
< 25.94	92.00	80.77%–97.78%	75.00	62.14%–85.28%
< 26.13	92.00	80.77%–97.78%	71.67	58.56%–82.55%
< 26.18	94.00	83.45%–98.75%	71.67	58.56%–82.55%

PCV2 viral loads determined by qPCR between 10³ to 10⁴ or above 10⁴ DNA copies/μL were defined as middle or strong positivity. The statistical analysis was performed based on the original Ct values determined by EZtargex.

Ct, cycle threshold; CI, confidence interval; PCV2, porcine circovirus type 2; qPCR, quantitative polymerase chain reaction.