Background Climate change and urban expansion pose significant challenges to controlling
Aedes aegypti mosquito populations, a primary vector of arboviruses such as dengue, Zika, and
chikungunya. This study aims assess how climate and anthropogenic factors will jointly shape Ae.
aegypti densities in Brazil, which is crucial to forecasting transmission risks and informing public health
strategies. Methods This study combined a biologically informed, stage-structured delay-differential
equation model with climate and anthropogenic data. Climate projections from the Coupled Model
Intercomparison Project Phase 6 under different Shared Socioeconomic Pathways (SSPs) were used to
forecast future climate scenarios from 2024 to 2080. Boosted Regression Trees integrated anthropogenic
factors like urbanisation, population growth, and urban accessibility. Model outputs were validated with
entomological surveillance data, and the basic reproductive number for dengue fever was used to assess
changes in disease transmission potential. Findings Our findings predicted that Ae. aegypti mosquito
density will increase nationally, but unevenly, exceeding thermal limits in North Brazil while rising
substantially in the South and Southeast. Increases in density were particularly pronounced under high
greenhouse gas emission scenario SSP5-8.5 (up to 92% in the Southeast). These trends were projected to
elevate the transmission potential for dengue fever, with Southeast Brazil facing the biggest increases due
to mosquito population growth outpacing human population expansion. Validation against historical data
confirmed model robustness. Interpretation By directly linking mosquito abundance to SSP-specific
emissions trajectories, our results show that climate mitigation can markedly reduce disease risk. Shifting
from SSP5-8.5 to SSP1-2.6 could cut projected mosquito density increases from 31% to 11% nationally
by 2080. The models spatial granularity and integration of local administrative boundaries support its
utility for national and sub-national health planning. Addressing compounded risks in vulnerable peri-
urban and rural populations will require coordinated interventions that span climate policy, vector control,
and health equity. Author summary Aedes aegypti mosquitoes transmit viruses like dengue, Zika, and
chikungunya, which are increasing in many parts of the world, including Brazil. Climate change and rapid
urban growth are likely to increase the risk of mosquito-borne disease outbreaks in the future. In this
study, we developed a model that combines mosquito biology with climate and urbanisation data to
estimate how mosquito populations might change in Brazil under different future climate and
development scenarios. Our model predicts that mosquito populations will increase significantly,
especially in the South and Southeast of Brazil, where conditions are becoming more favourable for
mosquito survival and reproduction. We also found that the risk of disease transmission is expected to rise
as mosquito numbers grow faster than the human population. These findings suggest that both climate
change and human development patterns are likely to increase the burden of mosquito-borne diseases. By
showing where and when mosquito risks are likely to be greatest, our study can help public health
authorities prepare and respond more effectively. It also highlights the importance of climate action to
reduce future health risks.
Redes Sociais