Speaker
Description
Background: Trachoma is the leading infectious cause of blindness globally and the second in Ethiopia. The disease is caused by Chlamydia trachomatis. Although the World Health Organization set a target to elimination trachoma by 2030 through the SAFE strategy, the current surveillance relies on clinical grading of trachoma which poorly correlate with ocular Chlamydia trachomatis infection after mass drug administration. Therefore, it is important to avail reliable and affordable diagnostic tools to monitor infection dynamics in trachoma endemic areas. Therefore, this study aimed to evaluate the diagnostic performance of Biomeme and Loop-Mediated Isothermal Amplification assays for detection of ocular Chlamydia trachomatis infection using Abbott RealTime PCR as the reference standard.
Methods: A total of 252 pooled ocular swabs were tested from January to march 2025 in Amhara Public Health Institute molecular trachoma laboratory. Pooled samples were tested using Abbott RealTime PCR, Biomeme,and LAMP assays. Diagnostic performance indicators including sensitivity, specificity, positive and negative predictive values, likelihood ratios, and area under the receiver operating characteristic curves were calculated.
Results: Abbott real time PCR identified 171 (67.9%) positive samples. The Biomeme assay demonstrated 100% sensitivity (95% CI: 97.9–100.0) but very low specificity (4.9%, 95% CI: 1.4–12.2), with an AUC of 0.525, indicating poor discrimination. Conversely, the LAMP assay achieved a sensitivity of 71.4% (95% CI: 63.9–78.0) and a specificity of 98.8% (95% CI: 93.3–99.9), with an AUC of 0.851 (95% CI: 0.80–0.89), reflecting very good diagnostic performance. The positive likelihood ratio (+LR) was 57.8, and the negative likelihood ratio (–LR) was 0.29, indicating robust diagnostic utility. Pairwise ROC comparison showed LAMP significantly outperformed than Biomeme (AUC = 0.326; p < 0.0001).
Conclusion and recommendations: The LAMP assay demonstrated high diagnostic accuracy, very good agreement with the Abbott RealTime PCR, and practical applicability for field-based trachoma surveillance. In contrast, the Biomeme assay showed poor specificity and limited diagnostic value. LAMP offers a rapid, affordable, and field-feasible alternative for detecting ocular Chlamydia trachomatis infection in resource-limited trachoma-endemic settings, supporting WHO-endorsed monitoring efforts toward trachoma elimination.
