Impact of Climate Change on the Global Expansion, Severity, and Transmission Dynamics of Dengue: A Systematic Review and Meta-Analysis

Introduction

Dengue is the most prevalent arboviral disease worldwide, with rapidly increasing incidence driven by climate change, urbanization, and global mobility. Rising temperatures, altered precipitation patterns, and extreme weather events have expanded the geographic range of Aedes mosquitoes, modifying dengue transmission dynamics and disease burden. We conducted a systematic review and meta-analysis to evaluate the impact of climate variables on dengue incidence, severity, and spatial expansion.

Methods

A systematic search of PubMed, Embase, Web of Science, and Scopus was conducted from January 2000 to December 2025, following PRISMA guidelines. Eligible studies included observational, ecological, and modeling studies assessing associations between climatic factors and dengue transmission, incidence, outbreaks, or severity. Primary outcomes were changes in dengue incidence and geographic expansion. Secondary outcomes included outbreak frequency and disease severity. Random-effects meta-analyses were performed when appropriate, and heterogeneity was assessed using the I² statistic.

Results

A total of 52 studies comprising data from over 45 countries were included. Increased ambient temperature, rainfall variability, and humidity were consistently associated with higher dengue incidence. Each 1 °C increase in mean temperature was associated with a pooled 12% increase in dengue risk (RR 1.12; 95% CI 1.08–1.16). Regions previously considered non-endemic demonstrated sustained autochthonous transmission, particularly in temperate and high-altitude areas. Climate-driven changes were also linked to longer transmission seasons, increased outbreak intensity, and expansion of hyperendemic zones. Significant heterogeneity reflected regional ecological variability.

Conclusions

Climate change is a major driver of the global expansion and intensification of dengue transmission. These findings underscore the urgency of integrating climate-informed surveillance, vector control strategies, and public health preparedness into global dengue prevention policies. Anticipatory models incorporating climate projections are essential to mitigate future epidemic risks.