Current and emerging molecular diagnostic approaches in the detection of human parasites

Microscopy and morphological identification remain the gold standard for diagnosing most parasitic infections, yet their limited sensitivity in asymptomatic or low-burden cases, along with technical constraints, has accelerated the adoption of molecular diagnostics. Over the past three decades, advances in nucleic acid amplification and sequencing technologies have transformed parasite detection by improving sensitivity, specificity, and reproducibility, enabling earlier intervention and stronger surveillance. PCR remains the foundation of molecular diagnostics, with real-time PCR and digital PCR improving analytical performance and quantification. Multiplex qPCR supports simultaneous detection of multiple pathogens, while dPCR enables absolute quantification and rare variant detection, although broader implementation is limited by instrument cost. Isothermal amplification methods such as tHDA, NASBA, LAMP, and RPA offer rapid, low-cost amplification at constant temperature and are well suited for field diagnostics in resource-limited settings. Next-Generation Sequencing has advanced genotyping and epidemiological surveillance by resolving cryptic species, resistance mutations, and mixed infections through targeted panels, whole-genome sequencing, and metagenomics. CRISPR/Cas-based assays provide rapid and sensitive nucleic acid detection with strong potential for point-of-care deployment due to their simplicity and adaptability. Emerging biomarkers, including circulating cell-free DNA, non-coding RNAs, and microRNAs in extracellular vesicles, offer promising non-invasive diagnostic strategies, though further validation is required. This review offers a concise overview of these molecular approaches, emphasizing recent innovations such as dPCR, NGS, CRISPR/Cas systems, and biomarker-based detection. For each method, core technical principles, representative applications, and comparative strengths and limitations are presented to illustrate their diagnostic potential.