CRISPR-Based Diagnostics for Neglected Tropical Parasitic Diseases: A Critical Appraisal of Verified Evidence, Persistent Gaps and Pathways to Implementation in Low- and Middle-Income Countries

Abstract

Clustered regularly interspaced short palindromic repeats (CRISPR) nucleases with collateral, sequence-activated nuclease activity have been proposed as a route to molecular-grade sensitivity at the point of care, and the proposal is unusually consequential for neglected tropical parasitic diseases, where control and elimination programmes are constrained less by therapeutic options than by the inability to detect light, asymptomatic and residual infection. This critical narrative review examines what the peer-reviewed evidence actually establishes about CRISPR-based nucleic acid detection for parasitic neglected tropical diseases, and what it does not. Literature was identified through structured searching of biomedical and multidisciplinary scholarly sources, supplemented by citation tracking and by institutional documentation, with a final search date of 4 July 2026, and every included source was verified against authoritative bibliographic records. The evidence is developing rapidly but remains structurally uneven. Analytical performance is consistently impressive, with reported limits of detection extending from single copies to the attomolar range across schistosomiasis, food-borne trematodiases, echinococcosis, strongyloidiasis, human African trypanosomiasis, leishmaniasis and toxoplasmosis. Clinical validation, by contrast, is sparse, geographically concentrated and methodologically fragile: several widely cited assays have been evaluated only on contrived specimens, animal models or fewer than one hundred clinical samples, comparisons are made almost exclusively against imperfect molecular reference standards, and reported sensitivity in the largest human evaluations has ranged from 56.1% to 100% depending on disease, target and specimen. No CRISPR assay for any parasitic neglected tropical disease has completed the multi-site accuracy evaluation, regulatory assessment and costing that would support programmatic adoption, and entire disease groups, including taeniasis and cysticercosis and human Chagas disease, have no validated assay at all. The principal barriers are not enzymatic but pre-analytical, infrastructural and regulatory. Progress requires target product profile-anchored evaluation in endemic settings, transparent reporting, integration of sample preparation, and manufacturing and regulatory pathways that do not presume high-income laboratory conditions.