Novel Assays and Biomarkers in Infectious Disease Detection: From Diagnosis and Prognosis to Therapeutic Monitoring and Cure Assessment

Infectious disease diagnosis remains central to clinical care, but current methods still have important limits. Clinical symptoms are often nonspecific, culture-based methods can be slow, serology depends on timing, and molecular tests may detect microbial material without always proving active disease. This review examines novel assays and biomarkers in infectious disease detection from a clinical perspective. It summarizes major diagnostic platforms, including advanced nucleic acid tests, syndromic panels, metagenomic sequencing, serological and antigen assays, point-of-care platforms, biosensors, and multi-omics approaches, and reviews pathogen-derived, host-response, and combined biomarker classes. It discusses how these tools can support diagnosis, prognosis, disease staging, therapeutic monitoring, and cure assessment. A central message is that analytical novelty alone is not enough: new assays must be accurate, timely, interpretable, and able to change patient management in real practice. Clinical symptoms and the physicians awareness of these remain critical along with the correct biomarkers. Translation is often limited by imperfect reference standards, limited external validation, poor standardization, workflow barriers, cost, and unequal access. Future priorities include stronger validation, simpler and standardized workflows, wider access through home (OTC) use, and better biomarkers for treatment response, cure, and relapse prediction.