Year-Round Dengue Surveillance in Tangerang Regency, Indonesia (2024): Clinical and Virological Features with Biomarker Evaluation.

Dengue remains a major public health concern in Indonesia. This study aimed to describe the epidemiology, clinical characteristics, immune responses, and genotype characterization of dengue virus (DENV) infections in Tangerang Regency, Indonesia. A year-round prospective surveillance was conducted from January 2024-January 2025 at a district hospital and two primary health centers. Febrile patients aged ≥4 years were tested using dengue NS1, IgM/IgG rapid tests, ELISA, and RT-PCR, and serum biomarkers (angiopoietin-2, IL-6, ferritin, sCD163) were quantified. Of 404 participants, 240 (59.4%) had confirmed dengue. Among RT-PCR-serotyped cases (n=192), the distribution was DENV-2 63/192 (32.8%), DENV-1 60/192 (31.3%), DENV-3 47/192 (24.5%), and DENV-4 22/192 (11.5%). Among hospitalized dengue cases (n=144), secondary infection (131/144, 91.0%) was associated with severe disease (adjusted OR=10.25; 95% CI: 1.71-197.90, p=0.034). Biomarker levels were elevated in dengue cases but did not discriminate severity, indicating the need for validation in larger cohorts using standardized definitions. Sequencing identified DENV-1 genotypes I and IV, DENV-2 Cosmopolitan, DENV-3 genotype I, and DENV-4 genotype IIa; one DENV-4 isolate carried an EDIII E384 D→H substitution warranting further investigation. Continued genomic surveillance and vaccine development that induces balanced, serotype-specific immunity are needed to support national and global dengue control.