Diagnostic performance of the TR Chagas Bio-Manguinhos rapid test for detecting anti-Trypanosoma cruzi IgG in human samples from three Southern Cone countries

Abstract

Chagas disease (CD) remains a major public health challenge in Latin America, largely due to persistent underdiagnosis, particularly in endemic and resource-limited settings. Rapid diagnostic tests (RDTs) offer a pragmatic approach to expand serological screening; however, their performance varies across epidemiological contexts and parasite genetic backgrounds. The TR Chagas Bio-Manguinhos test, based on recombinant chimeric antigens, has shown high sensitivity in previous evaluations, but data from Southern Cone remain limited. We conducted a cross-sectional diagnostic accuracy study using 311 anonymized human plasma samples obtained in Argentina, including 233 Trypanosoma cruzi-positive and 78 negative samples classified by a composite reference standard based on at least two independent serological assays. Diagnostic performance of the TR Chagas Bio-Manguinhos rapid test was assessed in terms of sensitivity, specificity, accuracy, likelihood ratios, diagnostic odds ratio, and agreement. Sensitivity was further stratified by country of origin (Argentina, Bolivia, Paraguay) and by cardiac involvement according to the Kuschnir classification. The TR Chagas Bio-Manguinhos test demonstrated high overall performance, with a sensitivity of 97.0% (95% CI: 93.9-98.5%), specificity of 94.9% (95% CI: 87.5-98.0%), and accuracy of 96.5% (95% CI: 93.8-98.0%). Agreement with the reference standard was almost perfect (κ = 0.91). Sensitivity remained consistently high across geographical origins and Kuschnir cardiac stages, with no statistically significant differences between subgroups. The negative likelihood ratio (0.03) indicated strong ability to rule out infection. These findings provide the first independent evidence supporting the high performance of the TR Chagas Bio-Manguinhos test in people from Argentina, Bolivia and Paraguay. The combination of very high sensitivity and robust specificity supports its use as a frontline serological screening tool for chronic T. cruzi infection in the Southern Cone, provided that reactive results are subsequently confirmed by laboratory- based assays in accordance with international guidelines.