Burden of Malaria and Dengue Across Global, Asian, and Chinese Populations Based on GBD 2021 Data: A Quantitative Assessment of Importation Risks to China

Background: Malaria and dengue continue to pose significant public health challenges in Asia, with differing temporal trends and regional distributions. However, comparative and long-term assessments of their disease burden and future trajectories remain limited. Methods: Using Global Burden of Disease Study 2021 data, we estimated age-standardized incidence rates (ASIR), disability-adjusted life years (DALYs-ASR), and estimated annual percentage changes (EAPCs) for global, Asian, and Chinese populations by age, sex, and socio-demographic index (SDI). Correlations with SDI and population density were analyzed, and an importation risk index for China was developed. Future trends to 2030 were projected using Bayesian age-period-cohort modeling. Findings: From 1990 to 2021, dengue ASIR increased globally and in China, particularly in middle-SDI regions, whereas malaria ASIR and DALYs-ASR declined substantially, with the most pronounced reductions observed in China. Dengue DALYs-ASR were highest among children under five, while incidence peaked in adolescents; malaria burden was concentrated in young children and young adults. Sex-specific differences were observed, with higher dengue incidence in females but greater DALY rates in males. Geographically, Southeast Asian countries contributed most to the estimated importation risk for both diseases. Projections indicate continued increases in dengue burden through 2030, alongside further declines in malaria. Conclusions: Malaria and dengue exhibit divergent epidemiological patterns across Asia, with declining malaria burden but rising dengue incidence. These findings highlight the need for differentiated control strategies, strengthened regional collaboration, and enhanced surveillance of cross-border transmission.