The impact of climate change on Aedes aegypti distribution and dengue fever prevalence in semi-arid regions: A case study of Tehran Province, Iran

Abstract

Introduction

Climate change profoundly affects ecosystems and public health, particularly by altering the dynamics of vector-borne diseases. This study investigates the impact of climate change on the distribution and biological behavior of Aedes aegypti mosquitoes and the prevalence of dengue fever in Tehran Province, a semi-arid region of Iran. Over the past two decades, the province has experienced significant climatic shifts, including a 7.3 % increase in average annual temperature, a 12.5 % decrease in rainfall, and a 50 % rise in the number of hot days, creating favorable conditions for vector proliferation.

Materials and methods

Climatic data analysis, field monitoring of mosquito populations, and species distribution modeling (SDM) were employed to understand the ecological and epidemiological dynamics of Aedes aegypti in Tehran. Key variables such as temperature, rainfall, and artificial water sources were analyzed. Predictive models assessed the expansion of suitable mosquito habitats under moderate (RCP4.5) and severe (RCP8.5) climate scenarios.

Results

Field data revealed an 87.5 % increase in mosquito density in urban areas and a doubling of densities in peri-urban and natural areas over two decades. Biological studies showed increases in mosquito lifespan (+50 %), egg production (+50 %), and larval development rates (+33 %) under warmer conditions. Predictive modeling indicated an 83 % expansion in suitable habitats by 2050 under the RCP8.5 scenario. Epidemiological data revealed a 200 % increase in dengue cases in urban areas and a 140–150 % rise in peri-urban and natural areas, driven by the expanding geographic range of Aedes aegypti.

Discussion

The findings highlight the critical role of climate change in driving mosquito population growth and disease transmission in semi-arid regions. Enhanced surveillance, climate-resilient urban planning, and integrated vector control measures are essential to mitigate these risks. This study provides actionable insights into the complex relationship between climate change and vector-borne diseases, underscoring the urgent need for targeted public health interventions to prevent future outbreaks.