PERFORMANCE ASSESSMENT OF A COMMERCIAL NS1 RAPID DIAGNOSTIC TEST FOR DENGUE VIRUS IN INDONESIAN HOSPITALS

Dengue virus (DENV) remains hyperendemic in Indonesia, with early detection crucial for effective patient management in the absence of specific antiviral therapies. This study evaluates the diagnostic performance of a commercial NS1 antigen rapid diagnostic test (RDT) under routine point-of-care conditions. A total of 646 febrile patients (with or without leukocytosis) presenting to Tabanan General Hospital, Bali (2017–2018) were enrolled. Serum specimens were tested using the Standard Diagnostics Bioline NS1 Ag RDT. Molecular confirmation involved both Flavivirus-specific RT-PCR and serotype determination via multiplex RT-PCR. DENV infection was confirmed molecularly in 67 patients (10.4%). The NS1 RDT identified 41 of these cases, corresponding to an overall sensitivity of 59.7% (95% CI: 44.5–74.9%) and a specificity of 99.8% (95% CI: 99.5–100.0%). Sensitivity was highest (> 75%) within the first 48 hours of symptom onset, declining to < 60% by day 3. The test demonstrated better sensitivity for DENV‑2, and least sensitivity for DENV‑4. The NS1 RDT shows significant value for early detection and epidemiologic surveillance in primary care settings, particularly within 48 hours of symptom onset. However, its sensitivity limitations beyond this period and for certain serotypes underscore the need for confirmatory molecular or serological testing for optimal case management.