Comparative evaluation of lateral flow assays to diagnose chronic Trypanosoma cruzi infection in Bolivia

Area of Science:

• Tropical Medicine
• Infectious Diseases
• Diagnostic Assay Development

Background:

• Bolivia faces the world's highest incidence of Chagas disease (CD), a chronic condition caused by Trypanosoma cruzi.
• Current diagnostic methods are complex, costly, and inaccessible, leading to low diagnosis rates (estimated 6% in Bolivia).
• Simplifying diagnostic pathways is essential for Chagas disease control and elimination efforts.

Purpose of the Study:

• To evaluate the performance of 10 commercially available lateral flow assays (LFAs) for Trypanosoma cruzi infection in Bolivia.
• To generate unbiased data on LFA sensitivity and specificity.
• To assess the utility of LFAs in improving Chagas disease diagnosis rates efficiently.

Main Methods:

• A retrospective, laboratory-based diagnostic evaluation study.
• Tested 470 serum samples (221 CD-positive, 249 CD-negative) using 10 LFAs and Bolivia's current diagnostic algorithm as the reference.
• LFAs were blinded and performed by three operators; performance was scored using a decision-tree algorithm.

Main Results:

• LFA sensitivities ranged from 62.2% to 97.7%, with 5/10 tests exceeding 90% sensitivity.
• Specificities ranged from 78.6% to 100%, with 6/10 tests exceeding 95% specificity.
• Four LFAs demonstrated high sensitivity (93-95%) and specificity (97-99%); agreement with reference tests was almost perfect (Kappa 0.83-0.94).

Conclusions:

• Several evaluated LFAs exhibit performance comparable to existing laboratory-based diagnostic methods for Chagas disease.
• LFAs offer a promising, simplified approach to improve diagnosis rates in resource-limited settings like Bolivia.
• Widespread adoption of accurate LFAs could significantly enhance Chagas disease management and control strategies.