Enhanced detection of Trypanosoma evansi in Cattle: Superior performance of LAMP compared to PCR and CATT/T. evansi test

Background: Trypanosoma evansi, the causative agent of surra, poses a major veterinary concern in tropical regions, particularly affecting cattle and buffalo. The disease leads to reproductive failures, including abortion, and significant economic losses. Early and accurate diagnosis is crucial for effective control, especially in endemic, resource-limited areas. Objectives: This study aimed to develop a loop-mediated isothermal amplification (LAMP) assay for rapid detection of T. evansi and evaluate its diagnostic performance in comparison with conventional polymerase chain reaction (PCR) and the CATT/T. evansi card agglutination test. Materials and methods: Four LAMP primers were designed to target the RoTat 1.2 variant surface glycoprotein (VSG) gene of T. evansi. Optimal reaction parameters, including temperature and incubation time, were established. The LAMP assay, conventional PCR, and the CATT/T. evansi card agglutination test were performed on 79 blood samples collected from cattle with suspected trypanosomiasis in northern Thailand (Lamphun and Chiang Mai). Diagnostic sensitivity, specificity, and agreement between tests were statistically analyzed. Results: The LAMP assay detected T. evansi in 32 (40.5%, 95% CI: 29.8-51.9%) samples, slightly outperforming PCR, which detected 30 (37.9%, 95% CI: 27.6-49.0%). However, this difference was not statistically significant (McNemar’s test, p=0.724). The CATT/T. evansi test yielded 45 (56.9%) positives but lacked the ability to differentiate active infection from prior exposure. Conclusion: The LAMP assay demonstrated high sensitivity, specificity, and rapid detection capabilities under simplified conditions, making it highly suitable for field applications. When paired with colorimetric or lateral flow readouts, LAMP offers a promising point-of-care diagnostic tool for improving trypanosomiasis control in endemic regions.