As the planet warms, mosquitoes find more places to thrive, enabling the increased spread of arboviruses.
Our planet is home to over 3,500 species of mosquitoes. Some are worse for the spread of diseases than others, like the Asian Tiger mosquito (Aedes albopictus, originating in southeast Asia) and the Yellow Fever mosquito (Aedes aegypti, originating in Africa).
It’s these two that scientists are concerned about in a new study published in Nature Microbiology by authors Moritz U. G. Kraemer, Robert C. Reiner Jr, and Nick Golding.
The populations of these two mosquito species are spreading, and it’s the result of a complex combination of three key factors:
- international trade
- rapid human population growth and travel, and
- climate change, particularly global warming.
As we continue to consume products sourced from all over the world, mosquito eggs find more places to hide and spread. Travel conditions need not be ideal, and they can hide in tyres and potted plants, surviving lengthy journeys. Furthermore, Asian Tiger Mosquito eggs can undergo diapause, lying dormant in colder climates (or winters) until conditions improve for adult survival.
Whenever we travel, we contribute to their spread, and our negative contributions to the environment increase the number of warm habitats mosquitoes need to thrive.
By 2050, almost half of humanity will be at risk of diseases carried by these mosquitoes.
- the Yellow Fever mosquito will spread to spread to 159 countries, and
- the Asian Tiger mosquito will spread to spread to 197 countries.
Increases in global temperatures and large urban environments will further fuel these spreads.
Efforts to reverse climate change will not be enough. If emissions are not reduced soon, it’s predicted these expansions will be more significant. Furthermore, it’s likely human populations will grow in places where these species are already established, increasing the risk to humans of contracting diseases carried by mosquitoes.
Ironically, climate change may also render certain high density areas inhabitable by humans, restricting the number of people who may be at risk of arboviruses. But that’s a little like saying the sun is safe because humans don’t live there.
Quarantine is more important than ever
Countries must consider effective means of entomological surveillance around key entry points such as airports and seaports. They must also develop rapid response protocols to prevent introduced mosquitoes from establishing permanent populations.
Every effort must be made to limit the spread and impact of mosquito populations.
Feature image Mehmet Karatay.