Enzyme-linked immunosorbent STI assays: development, current status and future perspective

Sexually transmitted infections (STIs) continue to pose major public health challenges globally, with millions of new cases reported annually. The asymptomatic characteristic of many STIs makes accurate and cost-effective diagnostic methods essential for screening and diagnosis. This paper evaluates the utility of enzyme-linked immunosorbent assays (ELISAs) in diagnoses of HIV, HPV, HSV, HBV, HCV, Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis and Treponema pallidum. Compared to nucleic acid amplification tests (NAATs), ELISAs have advantages that include minimal training requirements, lower costs, and suitability for community screening programs. Despite their practical advantages, conventional ELISAs face key performance limitations, cross-reactivity, lower sensitivity, and delayed detection, that have restricted their broader adoption, reducing the potential for ELISAs to become a standard STI detection method. Currently, advancements in ultrasensitive and digital ELISA technologies have greatly improved their accuracy and may improve the dilemma. This review describes current ELISA methodologies, efficacies, and limitations as observed in and reported for clinical applications and offers a comprehensive perspective on essential STI diagnostic improvements, motivated by the belief that ELISA techniques can significantly contribute to the early detection, treatment, and containment of STIs.