Nucleic Acid Amplification Tests for Candida Species Identification: A Systematic Review of Diagnostic Performance

Rapid and accurate identification of Candida species is critical for guiding antifungal therapy, especially with the emergence of intrinsically resistant pathogens. However, diagnostics using culture-based methods remain slow and labor-intensive, limiting timely treatment decisions. This systematic review evaluated the diagnostic performance and clinical applicability of nucleic acid amplification tests (NAATs) for Candida species identification using a PubMed search completed on 23 June 2025. A total of 888 records were screened, 333 full-text articles were assessed, and 158 studies were included based on criteria including comparison with standard diagnostic methods, diagnostic performance reporting, and involvement of clinical samples. PCR-based approaches were the most widely used, including conventional, nested, multiplex, real-time, and droplet digital PCR. Isothermal methods such as loop-mediated isothermal amplification (LAMP) and recombinase polymerase amplification (RPA) were increasingly represented. Common molecular targets included the ITS and 18S/28S rDNA regions. The risk of bias assessment was completed with the QUADAS-2 tool. Diagnostic performance varied depending on assay design, specimen type, gene target, and reference method. Excellent specificity and low limits of detection were achieved, especially with isothermal platforms offering the shortest turnaround times and greatest potential for point-of-care implementation. Multiplex assays were particularly advantageous for detecting mixed-species samples, while highly specific assays were optimal for distinguishing clinically important species such as Candidozyma auris, Nakaseomyces glabratus, and Pichia kudriavzevii. Overall, NAATs represent a promising diagnostic tool for Candida species identification, but broader clinical adoption will require improved standardization, validation across diverse patient populations, and clearer interpretation of fungal burden in the context of colonization versus infection.