A multicentre comparative study of serological methods for diagnosing Chagas disease in Brazil

BACKGROUND Chagas disease (CD), a neglected tropical disease caused by Trypanosoma cruzi, remains a significant often underdiagnosed public health challenge in endemic regions, affecting millions globally. Accurate and timely diagnosis is critical, but the performance of existing diagnostic methods varies widely in sensitivity and specificity. OBJECTIVES This multicentre study assessed the diagnostic performance of 17 serological assays for detecting anti-T. cruzi antibodies. METHODS Commercial enzyme immunoassays (EIA), indirect haemagglutination assays (IHA), indirect immunofluorescence assays (IIF), rapid diagnostic tests (RDT), and a chemiluminescent microparticle immunoassay (CMIA) were included in this study. FINDINGS Some EIA-based tests achieved 100% sensitivity, while IHAs and IIFs demonstrated reduced specificity. CMIA exhibited 100% sensitivity, highlighting its potential as a robust screening tool. Combining EIAs with IHAs or IIFs improved overall sensitivity, often surpassing 99%, although specificity remained variable. Cross-reactivity with other parasitic diseases posed challenges to specificity, particularly in assays employing crude antigens. MAIN CONCLUSIONS These findings emphasise the importance of tailoring diagnostic tool selection to regional epidemiological contexts and advancing antigen refinement to enhance diagnostic accuracy and accessibility, particularly in resource-limited settings.