Temporal Trends of Dengue in India (1990-2021): A Joinpoint and Age-Period-Cohort Analysis.

Dengue is a neglected tropical disease with a huge disease burden globally. Even though previous studies have focused on socio-demographic and climatic predictors of dengue, the independent effects of age, period, and birth cohort have not been studied. Here, using data from the Global Burden of Disease Study 2021, a joinpoint regression analysis and an age-period-cohort model were applied to identify temporal trends in age-standardized incidence and mortality rates and to estimate the longitudinal age curves, the rate ratios of period and cohort effects, the net drift, and the local drift values of dengue incidence and mortality in India, respectively. Dengue incidence and mortality trends in India showed a significant increase from 1990 to 2021. The average annual percent change (AAPC) of age-standardized incidence (AAPC: 1.39; 95% CI: 1.34, 1.44) and mortality (AAPC: 1.65; 95% CI: 1.23, 2.08) increased significantly over the study period. The Error, Trend, and Seasonality model forecasts a rise in cases from 28.86 million in 2020 to 32.06 million, while the ARIMA model projects an increase from 28.95 million to 33.43 million by 2031. The age-standardized rates of incidence, mortality, age, period, and cohort effects of dengue incidence and mortality in India show an increasing trend in all age groups from 1990 to 2021 in both sexes. The findings underscore the need for enhanced dengue prevention and control strategies in India.