CRISPR-Cas systems: Pioneering next-generation diagnostic tools for parasitic diseases

Parasitic diseases pose significant threats to both human and veterinary health, causing morbidity, mortality, and economic losses. Effective diagnostics are critical, yet conventional methods such as microscopy, serology, and polymerase chain reaction (PCR) are limited by low sensitivity, cross-reactivity, or dependence on costly equipment and skilled personnel. Isothermal amplification techniques, such as loop-mediated isothermal amplification (LAMP) and recombinase polymerase amplification (RPA), have improved point-of-care (POC) applications but remain limited by nonspecific amplification and reduced sensitivity for low-copy targets. Clustered regularly interspaced short palindromic repeats (CRISPR)-associated (Cas) systems have emerged as transformative tools in molecular diagnostics, offering high sensitivity, specificity, rapidity, and cost-effectiveness. This review presents an overview of CRISPR-Cas systems, their historical development, classification (Class 1 and Class 2, Types I-VI), molecular mechanisms, and diagnostic potential in parasitic diseases, with illustrative examples from studies published between 2017 and May 2025. Despite significant progress, CRISPR-based diagnostics face challenges such as off-target activity, dependence on nucleic acid amplification, and complex sample preparation. Future directions focus on amplification-free detection, multiplexed assay development, and integration with nanotechnology, microfluidics, smartphone-based devices, and artificial intelligence. CRISPR-Cas technologies thus represent a promising frontier in next-generation diagnostics for parasitic disease surveillance, control, and personalized healthcare in both human and veterinary health.