Rapid and Sensitive Detection of Schistosoma mansoni in the Intermediate Snail Hosts Using Loop-Mediated Isothermal Amplification (LAMP) Diagnostics.

Schistosomiasis is an important snail-borne neglected tropical disease, and detecting infected snails is a priority for its control and elimination. However, conventional parasitological methods, such as crushed snails and cercarial shedding, have limited sensitivity. In this study, we developed a novel loop-mediated isothermal amplification (LAMP) assay (smND1-LAMP) targeting the mitochondrial NADH dehydrogenase subunit 1 (ND1) gene of Schistosoma mansoni. The assay was optimized at 65 °C for 1 h and demonstrated a detection limit of one copy of the pUC57/smND1 recombinant plasmid. Its diagnostic performance was evaluated using laboratory-infected Biomphalaria snails and field-collected samples from Zimbabwe and Burkina Faso, and compared with microscopy, conventional PCR and SYBR Green real-time PCR (SGPCR). In laboratory experiments, smND1-LAMP achieved 100% specificity and 75% sensitivity, outperforming microscopy and showing a similar performance to SGPCR. In field surveys, smND1-LAMP detected a higher positive rate (25.9%) than conventional PCR (22.2%) in Burkina Faso, while microscopy failed to identify any positive snails. Both molecular methods identified infections that were missed by parasitological techniques. These findings demonstrate that smND1-LAMP assay is a sensitive, specific, and field-applicable tool for detecting S. mansoni infection in snails. It provides an effective alternative for routine surveillance and early warning of changing schistosomiasis endemicity.