Speaker
Description
Background: Accurate diagnosis of Mansonella perstans infection is essential for effective disease detection, treatment, and control programs. The Loop-Mediated Isothermal Amplification (LAMP) assay serves as a sensitive, straightforward molecular tool suitable for resource-limited environments. It is a rapid, cost-effective, and reliable diagnostic method. The LAMP assay employs three pairs of primers to amplify specific nucleic acid sequences at a constant temperature. This study aimed to optimize the LAMP assay for targeting the Mp419 repetitive sequence under various conditions, evaluating its application for detecting M. perstans in clinical blood samples collected in Ghana.
Methods: The research consisted of a laboratory-based experiment and an observational study involving 224 participants' blood samples. These samples were analysed for M. perstans using microscopy, quantitative PCR (Q-PCR), and the LAMP assay to assess the sensitivity and specificity of the LAMP method. The conditions for the LAMP assay were refined to enhance its detection threshold.
Results: The M. perstans LAMP assay demonstrated a clinical sensitivity of 72.98% (95% CI, 55.61-85.63), a specificity of 100% (95% CI, 97.49 – 100), and a positive predictive value (PPV) of 100% (95% CI, 84.5 -100) compared to an established M. perstans Q-PCR assay and microscopy. The Kappa value between LAMP PCR and microscopy was found to be 81.8% (95% CI, 70.8-92.8). The optimal condition for the LAMP assay to identify the M. perstans Mp419 repetitive sequence was determined to be amplification at a steady temperature of 63˚C for 45 minutes, with the lowest limit of detection of 0.05 mf/mL of whole blood.
Conclusions: The M. perstans-specific LAMP assay showed no cross-reaction with other filarial parasites, demonstrating diagnostic performance comparable to that of the combined efficacy of M. perstans Q-PCR and microscopy. Therefore, the LAMP assay can serve as an effective alternative molecular diagnostic tool for M. perstans, especially in low-resource settings.
Keywords: M. perstans, LAMP, diagnosis, PCR, accuracy.