Spatiotemporal expansion of Aedes aegypti and the dengue fever epidemic under climate change in China

Background Aedes aegypti is the primary vector of dengue fever, a disease whose transmission is strongly dependent on warm, humid climates. While the geographical and seasonal patterns of dengue are well-established, systematic projections of how climate change will affect the distribution of Aedes aegypti and dengue transmission risk in China remain limited. Method We integrated a phenological model with a dynamical mathematical model to project the future distribution and population dynamics of Aedes aegypti under multiple Shared Socioeconomic Pathways (SSPs). We assessed life-cycle completion (LCC) intensity at the municipal level across China and simulated detailed mosquito population dynamics and dengue transmission in six representative cities under sustainable (SSP1-2.6), regional rivalry (SSP3-7.0), and fossil-fueled development (SSP5-8.5) scenarios. Results Climate warming is projected to accelerate the developmental rate of Aedes aegypti , with the most severe risks under the SSP5-8.5. By the 2090s, southern coastal cities could average 26 LCCs per year, and approximately 90% of Chinese cities may sustain at least one annual generation. The mosquito’s range is expected to expand northward, with peak abundance shifting to September-October. Lengthened active seasons, particularly in the third and fourth quarters, are anticipated. Consequently, dengue incidence is projected to rise, peaking later in the year (October-November). In a high-emission future, Guangzhou could experience peaks of up to 11,000 daily cases. Conclusion Climate warming could increase the generational turnover, expand the geographic range, and prolong the seasonal activity of Aedes aegypti in China, thereby significantly elevating the risk of dengue transmission. These projections enhance our ability to predict outbreaks and are critical for informing proactive, targeted public health control strategies.