Table 1.

Diagnostic performance of TcTASV–ELISA

ELISA	Sensitivity, positive/total [95% CI]	Specificity, positive/total [95% CI]	AUC ROC,* cutoff [95% CI]
TcTASV-A	66%, 114/172 [57–73]	100%, 0/140 [97–100]	0.89, 1.768 [0.86–0.93]
TcTASV-B	2%, 3/172 [0–8]	100%, 0/140 [94–100]	0.62, 3.839 [0.53–0.72]
TcTASV-C	39%, 67/172 [32–47]	100%, 0/140 [97–100]	0.83, 1.643 [0.79–0.88]
Mix A + C	78%, 134/172 [71–84]	100%, 0/140 [97–100]	0.94, 1.425 [0.91–0.97]

The cutoff was selected through ROC curves to allow maximum sensitivity for a 100% specificity.¹⁵ Sera from infected patients (Tc+, N = 172) were positive at least with two commercial serological tests (lysate/recombinant-ELISA and/or IHA). Sera from patients without Trypanosoma cruzi infection (Tc−, N = 140) included healthy (N = 47), leishmaniasic (N = 73), and Strongyloides stercoralis–infected (N = 20) individuals. Origin of Tc+ samples: endemic areas in Argentina (N = 82, Salta Province; N = 80, Chaco Province) and Bolivia (N = 10). Sera from Salta Province and Bolivia were gently provided by Asociación para el Desarrollo Sanitario Regional (Buenos Aires Province) Foundation. Sera from Chaco Province were collected during cross-sectional studies in different rural settlements.¹⁷ Sera from patients without T. cruzi infection were from the collection of serum samples of the “Cátedra de Química Biológica” and/or “Instituto de Investigaciones de Enfermedades Tropicales,” National University of Salta. The protocol was approved by the Bioethics Committee; Faculty of Health Sciences, National University of Salta, Argentina.

* AUC ROC interpretation: values between 0.5 and 0.7 indicate low accuracy, between 0.7 and 0.9 indicate moderate accuracy and may be useful for some purposes, and greater than 0.9 indicate high accuracy.