Journal of Molecular Diagnostics 2020

Development and evaluation of a 3D Printer-based DNA extraction method coupled to loop mediated isothermal amplification (LAMP) for point-of-care diagnosis of congenital Chagas disease in endemic regions.

Wehrendt DP, Alonso-Padilla J, Liu B, Panozo LR, Nina SR, Pinto L, Lozano D, Picado A, Abril M, Pinazo MJ, Gascón J, Torrico F, Wong S, Schijman AG
Vertical transmission of T. cruzi is the cause of congenital Chagas disease, a re-emerging infectious disease that affects endemic and non-endemic regions alike. An early diagnosis is crucial because its prompt treatment achieves a high cure rate, precluding evolution to symptomatic chronic Chagas disease. However, early diagnosis involves low sensitive parasitological assays, making necessary serological confirmation after nine months of life. Aiming at implementing early diagnostic strategies suitable for minimally equipped laboratories, a T. cruzi-LAMP prototype was coupled to an automated DNA extraction device re-purposed from a 3D printer (PrintrLab). The whole process takes less than three hours to yield a result with an analytical sensitivity of 0.1 - 2 parasite equivalents per ml depending on the T. cruzi strain. Twenty five blood samples from neonates born to seropositive mothers were tested blindly. In comparison to qPCR, the PrintrLab - LAMP duo strategy showed high agreement, while both molecular-based methodologies yielded an optimal sensitivity and specificity with respect to congenital Chagas disease microscopy-based diagnosis. The PrintrLab-LAMP detected all ten congenitally transmitted T. cruzi infections, showing promise for point-of-care early diagnosis of congenital Chagas disease. Copyright © 2020. Published by Elsevier Inc.