The Dengue NS1 (Non-Structural Protein 1) test is a key diagnostic blood test for early detection of dengue fever, identifying the NS1 protein released by the virus in the first 1-7 days of symptoms, even before antibodies appear. It helps doctors confirm active dengue infection quickly for prompt treatment, often using ELISA or rapid test formats, and differentiates it from other fevers, though combining it with IgM/IgG antibody tests or PCR offers comprehensive diagnosis, especially after the first week