Laboratory evaluation of five rapid diagnostic tests for the serological diagnosis of chronic Trypanosoma cruzi infection in Yucatán, Mexico

Chagas disease (CD), caused by Trypanosoma cruzi, is a significant public health challenge in Latin America, where an estimated 70% of infected individuals remain undiagnosed. Rapid diagnostic tests (RDTs) offer a promising solution for new screening strategies, yet their performance has not been systematically assessed in Mexican cohorts. Here, we evaluated the diagnostic performance of five RDTs: Chagas Rapid Test (Certum), Bio-Chagas Rapid Test (Mexlab), BiolineTM Chagas Ab (Abbott), Chagas Rapid Test (Amunet) and Chagas Sero K-SeT (Coris BioConcept). Performance was tested using 79 archived human serum samples from Yucatán. All tests were benchmarked against the diagnostic reference algorithm established by the Mexican Official Norm (NOM), where samples were characterised as positive if they were reactive to ≥ 2 conventional serological assays (Chagatest Lisado, Chagatest Recombinante v4.0 and Chagatest HAI). The RDTs demonstrated variable diagnostic sensitivity. The BiolineTM Chagas Ab test demonstrated the highest sensitivity (97.2%, 95% CI: 85.5 - 99.9; 35/36 positive samples detected) and almost perfect statistical agreement with the NOM reference algorithm (κ= 0.90; p < 0.0001). Similarly, the Chagas Sero K-SeT prototype showed a high sensitivity (91.7%, 95% CI: 77.5 – 98.2; 33/36 positive samples detected) and substantial concordance (κ= 0.87, p < 0.0001) with the NOM-based composite result. In contrast, the remaining RDTs demonstrated low sensitivities (Certum: 0.0%, 95% CI: 0.0–9.7; Mexlab: 5.6%, 95% CI: 0.7–18.7; Amunet: 33.3%, 95% CI: 18.6–51.0), limiting their suitability for CD diagnostic algorithms, at least in Yucatán. Specificity was consistently high across the RDTs, ranging from 93.0% to 100% (95% CIs: 80.9–100). These findings underscore the need to locally validate diagnostic tools. The BiolineTM Chagas Ab and Chagas Sero K-SeT tests met the WHO benchmarks for RDT performance and, if validated in larger cohorts, could strengthen the screening of T. cruzi infection and epidemiological surveillance in Mexico.