A deadly tropical virus could become a growing threat in London and other major European cities due to climate change, scientists have warned.
Dengue fever, which is spread by the Asian tiger mosquito, has been moving steadily northward in Europe since first appearing in Albania in 1979.
A new study published in Global Change Biology found the mosquito has accelerated its spread in France, moving from about four miles per year in 2006 to 12 miles per year in 2024.
“Extrapolating from the results, it is estimated that the mosquito could establish itself in northern France within a decade, from where it could easily reach London, which is already climatically suitable for hosting this vector,” said Andrea Radici of Montpellier University, the lead author of the study.
The research team used climate and environmental modelling alongside two decades of data to track the movement and expansion of Aedes albopictus, the scientific name for the Asian tiger mosquito.
They found that while southern Europe has long been suitable for the species, large cities further north, including London, Vienna, Strasbourg and Frankfurt, are now climatically favourable for the mosquito.
The study warns that recent outbreaks of dengue in Europe could signal a broader trend, with the risk of transmission expanding from Mediterranean coasts into western France and northern Spain.
Although most people infected with dengue recover, the disease can cause severe complications, including internal bleeding, sudden drops in blood pressure and even death.
The World Health Organisation (WHO) said the number of dengue cases has increased significantly in recent decades. There were 14.6 million cases reported to the WHO in 2024, compared to 505,430 cases in 2000.
The disease is now endemic in more than 100 countries, the WHO said.
The European Centre for Disease Prevention and Control recorded 304 cases of dengue in 2024, compared with a cumulative total of 275 cases over the previous 15 years.
Scientists believe this sharp increase may indicate that dengue is on the path to becoming endemic in parts of Europe, fuelled both by climate change and rising levels of international travel.
Europe has been warming twice as fast as the global average since the 1980s, according to the EU’s Copernicus Climate Change Service.
The EU monitoring agency says that 2024 was the hottest year on record both globally and in Europe, which experienced its second-highest number of ‘heat stress’ days.
