A comparative analysis of rapid diagnostic tests and enzyme-linked immunosorbent assays for dengue diagnosis: a retrospective study in a tertiary care hospital in India

Dengue fever remains a major public health concern in India, where rapid and accurate diagnosis is essential for effective patient care and outbreak control. While enzyme-linked immunosorbent assay (ELISA) serves as the diagnostic standard, NS1 antigen-based rapid diagnostic tests (RDTs) offer faster and more accessible alternatives, particularly in resource-limited settings. This retrospective study analyzed 3,488 patient samples tested using both NS1Ag-RDT and NS1Ag-ELISA between January 2023 and December 2024. Using ELISA as the reference standard, the diagnostic accuracy of NS1Ag-based RDT was determined. 1,036 cases were ELISA-positive and 2,452 cases were ELISA-negative; the RDT identified 988 true positives, 2,274 true negatives, 178 false positives, and 48 false negatives. The NS1Ag-RDT demonstrated a sensitivity of 95.36% and specificity of 92.74%, indicating strong agreement with NS1Ag-ELISA. These findings support the utility of NS1Ag-based RDTs as reliable tools for early dengue diagnosis, while highlighting the need for multicentric studies incorporating RT-PCR to further validate diagnostic performance across diverse settings. IMPORTANCE: Dengue virus infection continues to represent a public health burden in endemic regions, where timely and accurate diagnosis is crucial for effective patient management and outbreak control. In this context, NS1 antigen-based diagnostic assays play an essential role in routine clinical practice, particularly in resource-limited settings due to limited access to molecular diagnostics. This study provides robust, real-world evidence on the diagnostic performance of NS1 antigen-based rapid diagnostic tests through a large retrospective analysis of 3,488 patient samples collected over a 2-year period at a tertiary care center in India. The findings demonstrate high sensitivity and specificity of NS1Ag-RDTs when compared with NS1Ag-based enzyme-linked immunosorbent assay (ELISA), and further highlight seasonal variations in diagnostic accuracy, offering clinically relevant insights that can inform diagnostic strategies during peak transmission periods. This work strengthens the evidence base supporting NS1-based diagnostics in dengue-endemic settings and contributes data of significant relevance to virology-focused research and public health practice.