Figure 2.

Receiver-operating-characteristic curve for skin parasite load as the predictor of positive results by xenodiagnosis in post-kala-azar dermal leishmaniasis patients. The indicated threshold of 2.61 log₁₀ parasites per microgram genomic DNA in skin biopsy shows sensitivity of 0.74 (95% confidence interval [CI], 0.44–0.92) and specificity of 0.90 (95% CI, 0.64–1). The threshold appears to be a better-than-random classifier because the lower bound of the 95% CI for the area under the curve (AUC) is >0.5 (AUC 95% CI, 0.70–0.90). (All CIs are bias-corrected CIs computed by bootstrapping with 10000 replicates.) Abbreviation: ROC, receiver-operating-characteristic.