DNA-based Molecular Monitoring of Parasitic Infections in Invasive and Native Snail Hosts

Aims: This study aims to evaluate the ecological impacts of invasive freshwater snail species on parasite transmission dynamics and to assess the effectiveness of DNA-based surveillance techniques in monitoring parasitic infections and associated risks to native snail populations. Methodology: This study employed a mini-review and meta-synthesis approach to evaluate peer-reviewed research articles investigating invasive snail–parasite–host interactions. The review synthesized findings from studies conducted globally between 1997 and 2024, with a particular focus on case studies from Zimbabwe, Brazil, the USA, Egypt, and Thailand. Relevant literature was identified through structured database searches in PubMed, Scopus, and Web of Science, targeting studies that applied molecular diagnostics and ecological modeling frameworks. Included studies utilized tools such as environmental DNA (eDNA), nested and multiplex PCR, loop-mediated isothermal amplification (LAMP), microsatellite genotyping, and DNA barcoding. Data on sampling methodologies, prevalence rates, host susceptibility, and spatial risk modeling were extracted and synthesized to reveal patterns in parasite spillover, spillback, and emerging biodiversity threats associated with invasive host-parasite systems. Results: Across four major sites, 1,250 snails were sampled—650 invasive and 600 native—with DNA barcoding achieving 98% species-level accuracy. Molecular assays identified elevated parasite prevalence in native species compared to invasives (e.g., Physa gyrina 45% vs. Bithynia tentaculata 20%; Radix natalensis 30% vs. Melanoides tuberculata 10%). eDNA showed 95% sensitivity for Schistosoma mansoni and 90% for Centrocestus formosanus, detecting parasite presence in up to 80% of surveyed water bodies. Risk assessments revealed a positive correlation between invasive snail density and native snail infection rates (p < 0.05). Use of natural molluscicides (e.g., Achyranthes aspera) reduced invasive snail populations by 70% and native infection rates by 25%. Conclusion: Invasive snails play a central role in modifying parasite transmission landscapes, posing significant risks to native biodiversity and public health. DNA-based tools offer accurate, non-invasive diagnostics essential for surveillance and targeted mitigation. Standardization of protocols, integration with ecological models, and expanded genetic databases are needed to strengthen control efforts and conservation planning.