Epidemiological Trends, Serotypic Distribution, and Forecasted Burden of Dengue in India (2010-2023): A Comprehensive Secondary Data Analysis.

BACKGROUND OBJECTIVES: Dengue fever is the world's most rapidly expanding vector-borne viral disease. India bears an estimated one-third of the global burden-a modelling-derived estimate. The epidemiological picture remains fragmented across surveillance streams with well-documented under-reporting of both cases and deaths. To characterise temporal trends in reported dengue cases and deaths in India from 2010 to 2023; to compare case fatality ratios from two independent official government data streams; to assess state-level distribution and serotypic patterns; and to synthesise published seroprevalence estimates from distinct peer-reviewed sources. METHODS: Pre-specified secondary data analysis following STROBE guidelines for observational epidemiology. No primary data collection. Data derived from National Centre for Vector Borne Diseases Control (NCVBDC) national passive surveillance records, Registrar General of India (RGI) Medical Certification of Cause of Death 2023, GBD Study 2021 outputs, and peer-reviewed Indian epidemiological studies (2018-2024). Annual reported cases, deaths, and case fatality ratios (NCVBDC vs. RGI); state-level dengue burden; dengue virus (DENV) serotype distribution; pooled seroprevalence; and synthesised autoregressive integrated moving average (ARIMA)-based case projections through 2026. RESULTS: Reported cases rose ten-fold from 28,292 in 2010 to 289,235 in 2023. NCVBDC recorded 485 deaths (CFR 0.17%) versus 3,254 RGI-certified deaths-a 571% discrepancy. INTERPRETATION CONCLUSION: GBD-based age-standardised incidence rose at an average annual percent change (AAPC) of 1.39% (95% CI: 1.34-1.44) and mortality at 1.65% (95% CI: 1.23-2.08) over 1990-2021. Pooled seroprevalence was 56.9% nationally (Ganeshkumar et al . [5]) and 81% in an urban Pune cohort (Mishra et al . [18]). DENV-2 was dominant nationally (45% in western UP). Synthesised ARIMA models project 309,836 cases (95% CI: 240,337-379,334) by 2026.