Comparison of nucleic acid sequence-based amplification and loop-mediated isothermal amplification for diagnosis of human African trypanosomiasis

• Published in: Diagnostic microbiology and infectious disease 2014-02, Vol.78 (2), p.144-148
• Main Authors: Mugasa, Claire M, Katiti, Diana, Boobo, Alex, Lubega, George W, Schallig, Henk D.F.H, Matovu, Enock
• Format: Article
• Language: English
• Subjects: Case-Control Studies; Human African Trypanosomiasis (HAT); Humans; Infectious Disease; Internal Medicine; LAMP; Molecular Diagnostics; NASBA; Nucleic Acid Amplification Techniques - methods; Reproducibility of Results; Sensitivity and Specificity; Trypanosoma - classification; Trypanosoma - genetics; Trypanosoma brucei gambiense - genetics; Trypanosomiasis, African - diagnosis
• ISSN: 0732-8893; 1879-0070
• DOI: 10.1016/j.diagmicrobio.2013.06.025

Abstract Diagnosis of human African trypanosomiasis (HAT) using molecular tests should ideally achieve high sensitivity without compromising specificity. This study compared 2 simplified tests, nucleic acid sequence-based amplification (NASBA) combined with oligochromatography (OC) and loop-mediated isothermal amplification (LAMP), executed on 181 blood samples from 65 Trypanosoma brucei gambiense HAT patients, 86 controls, and 30 serological suspects from Uganda. Basing on the composite reference standard, the diagnostic sensitivity and specificity of NASBA were 93.9% (95% confidence interval [CI] = 84.9–98.3%) and 100% (95% CI = 94.9–100%), respectively. The same parameters for LAMP were 76.9% (95% CI = 64.8–86.5%) and 100% (95% CI = 91.6–100%), respectively. The level of agreement between LAMP and microscopy was good with a kappa (κ) value of 79.2% (95% CI = 69.4–88.9%), while that of NASBA-OC/microscopy was very good (κ value 94.6%; 95% CI = 89.3–99.8%). The sensitivity of NASBA-OC was significantly higher than that of LAMP (Z = 2.723; P = 0.007). These tests have potential application to HAT surveillance.