Genomic evolution of major malaria-transmitting mosquito species uncovered
Sequencing hundreds of Anopheles funestus mosquitoes provides new insights into the evolutionary patterns of this important human malaria-transmitting species
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Journal
Science
Article Title
Genomic diversity of the African malaria vector Anopheles funestus
Article Publication Date
18-Sep-2025
Two studies explore the genomic diversity of deadly mosquito vectors
Summary author: Walter Beckwith
Two of the world’s deadliest mosquito vectors – Aedes aegypti and Anopheles funestus – have evolved, spread, and adapted in ways that complicate global disease control, two studies show. The findings trace the human-linked origins of Ae. aegypti’s invasive lineage. They also reveal the rapid emergence of insecticide resistance in An. funestus. Collectively, they reveal the urgent need for more tailored and innovative interventions against malaria and dengue. Top of Form“Both [studies] provide important insights into the … the complex role that human activity, both passive and intentional, plays in their movement and adaptations,” writes Tamar Carter in a related Perspective. “These processes have led to complex subspecies genomic diversity that likely translates to functional diversity that is yet to be fully elucidated.” Bottom of Form Mosquito vector-borne diseases represent a major global health challenge, with malaria and dengue each causing hundreds of millions of infections annually, worldwide. The increasing mobility of people and goods has enabled mosquitoes, once confined to relatively narrow regions, to spread widely and adapt to new environments. Although modern genomic analyses could provide insight into the origin, evolution, spread, and control of these vectors, individual mosquito species are unequally represented in studies. Here, in a pair of studies, researchers analyze genomic data from Ae. aegypti and An. funestus mosquitoes to reconstruct their evolutionary and demographic histories.
In one study, Jacob Crawford and colleagues investigated Ae. aegypti – the primary vector of dengue, chikungunya, and Zika. The precise origin of the globally invasive Ae. aegypti has long been debated. Crawford et al. sequenced 1206 genomes from 73 globally distributed populations, using coalescent and phylogenetic analyses to disentangle ancient from recent migration events. According to the findings, after evolving a preference for humans in West Africa, Ae. Aegypti made its way to the Americas during the Atlantic slave trade, with the globally invasive lineage ultimately arising in the Americas. More recently, this invasive lineage has re-entered Africa and interbred with native populations, coinciding with increased dengue outbreaks and the spread of insecticide-resistance mutations.
In another study, Marilou Boddé and colleagues performed a sweeping genomic analysis of An. funestus to investigate how this major malaria vector has adapted, particularly under vector control pressure. Boddé et al. sequenced 701 modern and historic An. Funestus mosquitoes from 16 African countries. The findings revealed a complex population structure – while some populations showed strong geographic structuring, others were genetically connected across wide distances, with distinct lineages emerging in places like North Ghana and South Benin. According to the authors, this diversity suggests that uniform control strategies are unlikely to succeed, emphasizing the need for locally tailored interventions. Moreover, by comparing modern samples with century-old museum specimens, the team showed that insecticide resistance arose both through independent mutations and the spread of resistant lineages. Most insecticide resistant variants found in modern An. Funestus were not found in historical species from as recent as 1967, suggesting rapid emergence. Boddé et al. also discovered promising gene drive targets within An. Funestus, which could enable more effective and strategic vector control efforts.
For reporters interested in trends, an August 2025 Science Translational Medicine study by Quandelacy et al. provided an in-depth analysis of dengue transmission in the Americas, revealing regional outbreak patterns and how they are shaped by climatic factors.
Journal
Science
Article Title
1206 genomes reveal origin and movement of Aedes aegypti driving increased dengue risk
Article Publication Date
18-Sep-2025
Hotspots of mosquito-borne disease risk predicted in Brazil in coming decades
Mitigating climate change could slow mosquito population growth, lowering disease risk
PLOS
image:
Rio de Janeiro.
view moreCredit: Raúl Escobar, Unsplash (CC0, https://creativecommons.org/publicdomain/zero/1.0/)
A new study suggests that the risk of mosquito-borne illness in Brazil will rise significantly by the year 2080, but that climate action could help. Katherine Heath of the Burnet Institute, Melbourne, Australia, and colleagues present these findings September 18th in the open-access journal PLOS Neglected Tropical Diseases.
In many parts of the world, mosquitos of the species Aedes aegypti transmit disease-causing viruses—such as dengue, Zika, and chikungunya—when they bite people to feed on blood. Prior research has linked climate change and urban growth to higher future risk of mosquito-borne disease. In Brazil, warmer temperatures and changing rainfall patterns already appear to be contributing to higher dengue rates.
However, predictions of future mosquito-borne disease risk are hampered by the difficulty of mathematically capturing the interplay between climate change, urbanization, and mosquito biology. To address that challenge, Heath and colleagues developed a new mathematical model that combines climate and anthropogenic factors with delay-differential equations describing Ae. Aegypti survival and reproduction. The model accounts for the impacts of temperature and rainfall on mosquito biology at different life-cycle stages, as well as the impacts of urban expansion and human-mosquito interaction on disease transmission and mosquito population growth.
The researchers used the model to predict future mosquito population density across Brazil from 2024 through 2080 under different Shared Socioeconomic Pathways, a set of plausible future climate and societal scenarios that include different levels of climate change mitigation, urban growth and greenhouse gas emissions.
The model predicts that, under the lowest emissions scenario, Brazil’s overall Ae. Aegypti density will be 11 percent higher by 2080 than in 2024. In the highest emissions scenario, density is predicted to increase 30 percent nationwide by 2080, but with hotspots in the South and Southeast where density will nearly double.
With rising Ae. Aegypti density, dengue transmission is predicted to increase nationally—with the biggest increases in Southeast Brazil, where mosquito population growth is predicted to outpace human population growth.
These findings suggest that reducing emissions could reduce future disease risk. This study could also help inform national policies and local public health planning efforts.
The authors add, “Brazil already carries one of the world’s highest burdens of mosquito-borne disease, and our results show these pressures could grow in the coming decades.”
“Our model went beyond asking where mosquitoes might survive: it estimated how many there will be and what that means for future disease outbreaks.”
“The difference between a high- and low-emissions future is stark: strong climate action could cut Brazil’s projected mosquito density increases by two-thirds.”
In your coverage, please use this URL to provide access to the freely available paper in PLOS Neglected Tropical Diseases: https://plos.io/47AXJ7Q
Citation: Heath K, Muniz Alves L, Bonsall MB (2025) Climate change, urbanisation and transmission potential: Aedes aegypti mosquito projections forecast future arboviral disease hotspots in Brazil. PLoS Negl Trop Dis 19(9): e0013415. https://doi.org/10.1371/journal.pntd.0013415
Author countries: Australia, United Kingdom, Brazil
Funding: This work was supported by a PhD studentship [BB/M011224/1] from the Biotechnology and Biological Sciences Research Council (BBSRC) to KH. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Journal
PLOS Neglected Tropical Diseases
Method of Research
Computational simulation/modeling
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