Europe at Risk of Endemic Mosquito-Borne Diseases Due to Climate Change

Dengue and chikungunya—two viral diseases once largely confined to tropical regions—could soon become endemic in parts of Europe as climate change drives the spread of tiger mosquitoes further north, new research has warned.

Published on Thursday in The Lancet Planetary Health, the study suggests that global warming, primarily caused by human activity, is creating favourable conditions for Aedes albopictus, commonly known as the tiger mosquito, to thrive across more temperate European regions. This mosquito species is a known carrier of both dengue and chikungunya viruses.

Currently, around half of the world’s population is at risk of contracting these mosquito-borne illnesses. While both diseases typically cause fever and flu-like symptoms, they can prove fatal in rare cases.

The researchers examined the influence of various factors—particularly climate—on the presence and transmission of the viruses in Europe over the last 35 years. They found that both the frequency and severity of outbreaks have increased since 2010, closely tracking rising temperatures.

In 2024, the hottest year on record, the European Union recorded just over 300 dengue cases, compared to 275 cases in total during the previous 15 years. Recent outbreaks have occurred in Italy, France, Spain, and Croatia.

“The EU is shifting from occasional outbreaks of Aedes-borne diseases to a state where these illnesses may become endemic,” the researchers noted.

The findings indicate that higher temperatures significantly raise the likelihood of disease outbreaks, and under worst-case climate scenarios, the frequency of such outbreaks could be up to five times higher by 2060.

Interestingly, the study also found that outbreaks tend to be reported more often in wealthier regions, possibly due to greater access to testing—raising concerns that underreporting may be masking the true scale of infections in poorer communities.

The French Indian Ocean territory of Réunion has recently suffered a severe chikungunya outbreak. In addition to dengue and chikungunya, tiger mosquitoes are also capable of transmitting the zika and West Nile viruses, although these were not part of the latest study.