Mosquito Invasions on the Rise: How Warming Climates Spread Disease

Seasonal peaks of mosquito outbreaks under future climate conditions, if global warming continues, are expected to be higher and longer.
Research shows that larger parts of the year will be suitable for the development of the mosquito Aedes aegypti, known as a carrier and transmitter of diseases such as dengue fever, Zika, yellow fever, and chikungunya, which will accelerate the spread of these diseases both in areas already exposed and in areas where these mosquitoes are currently absent.

Climate change will increase the mosquito invasions in regions including China, the United States and Europe.
Analysis results indicate that the expansion of the mosquito’s distribution area will be rapid, estimated at 2.4–2.5 times faster by 2050.
Even earlier, by 2030, Europe is expected to become more suitable for these mosquitoes, especially in countries such as Spain, Portugal, Greece and Turkey.

The study also indicates an acceleration in the completion rate of mosquito life cycles that transmit diseases.
Data collected from 1950 to 2000 show that the world has become 1.5% more suitable for mosquito reproduction per decade.

Zika and Chikungunya are currently concentrated mainly in developing countries and regions with tropical and subtropical climates.
According to researchers, climate change is already affecting disease risks in these regions and exposing areas and countries that were previously unaffected or only minimally exposed.

The research reviewed existing scientific literature, synthesizing conclusions from a series of laboratory experiments and translated the results to present growth curves of mosquitoes at all stages of their life cycle.
Phenological models method that assess growing degree days (GDDs) were then used to link variables and forecast the species ability to complete its life cycle under given environmental conditions.

Due to the broad impact of mosquito-borne disease transmission, a wide research base exists on mosquito activity.
Laboratory experiments provide good understanding of factors enabling mosquito growth, timing, and growth rate.
The way mosquitoes respond to environmental variables such as temperature or rainfall is not sure and how these responses translate into changes in mosquito distribution as climate changes.
Without clear understanding of these changes, preparation for future transmission risks is difficult.

GDD index indicates the number of days required for each species with certain temperatures to grow and complete its life cycle stages.
Using different temperature and rainfall data in the model, researchers could estimate the speed at which mosquitoes could grow and predict the number of generations they could produce.


Researchers estimate that the method of transferring laboratory knowledge to global models to create environmental maps and future timelines will allow insights at the local level and provide policy recommendations for mosquito management.