CRISPR-Based Point-of-Care Diagnostics for Enteric Pathogens in Low-Resource Settings: A Narrative Review

Enteric infections caused over 500,000 deaths annually, yet culture and PCR diagnostics were largely inaccessible in rural healthcare settings. CRISPR-based diagnostics (CRISPR-Dx) offered amplification-free detection at ambient temperature within 30 minutes. This narrative review synthesized evidence on the analytical and field performance of CRISPR-Dx for detecting Salmonella, Shigella, Campylobacter, diarrhoeagenic Escherichia coli, and Vibrio species in low-resource settings. Systematic searches of PubMed, Web of Science, medRxiv, and bioRxiv (January 2018–December 2023) identified 18 studies: eight laboratory validation studies, six clinical cohorts, and four field pilots. Pooled sensitivity for Shigella spp. across five studies was 93.2% (95% CI: 88.4–96.1%) and specificity 97.7% (95% CI: 95.4–99.1%). Detection limits ranged from 10¹–10² CFU per reaction. Field pilots used lyophilised CRISPR reagents and smartphone-based fluorescence readers, achieving door-to-result times of 90–120 minutes. Where comparable diagnostic accuracy data were available, pooled sensitivity and specificity estimates were calculated using a random-effects mode. Key barriers included cold-chain requirements for guide RNAs and lack of multiplex panels. CRISPR-Dx demonstrated diagnostic accuracy comparable to qPCR and superior to rapid antigen tests, but development of multiplex lyophilised assays and streamlined WHO prequalification remain priorities for widespread adoption, with implications for diagnostic stewardship and antimicrobial resistance mitigation in low-resource settings.