Excruciating tropical disease can now be transmitted in most of Europe, study finds | Infectious diseases
A painful tropical disease, chikungunya, is now capable of being transmitted by mosquitoes across much of Europe, according to a recent study. Rising temperatures, linked to the ongoing climate crisis, are extending the period during which transmission is possible, raising concerns about potential outbreaks in previously unaffected areas.
The Expanding Threat of Chikungunya
The research, published in the Journal of Royal Society Interface, represents the first comprehensive assessment of how temperature impacts the incubation period of the chikungunya virus within the Asian tiger mosquito. Scientists discovered the minimum temperature required for infection to occur is 2.5C lower than previously estimated – a finding described as “quite shocking” by researchers.
Chikungunya virus was first identified in 1952 in Tanzania and historically remained confined to tropical regions, where millions of infections occur annually. The disease is characterized by severe and prolonged joint pain, which can be debilitating and, in some cases, fatal for young children and older adults.
While a small number of cases have been reported in over 10 European countries in recent years, larger outbreaks – involving hundreds of cases – were recorded in France and Italy in 2025. These outbreaks were often linked to travelers returning from tropical regions with active infections.
Climate Change and Mosquito Expansion
The Asian tiger mosquito (Aedes albopictus) has been steadily moving northward across Europe as temperatures increase. Although detected in the UK, it has not yet become established there. The study highlights that the rate of global warming in Europe is approximately double the global average, accelerating the risk of disease spread.
Sandeep Tegar, lead author of the study from the UK Centre for Ecology and Hydrology (UKCEH), stated, “The lower temperature limit for virus spread matters a lot, so our new estimates are quite shocking. The northward expansion of the disease is just a matter of time.”
Dr. Steven White, also at UKCEH, emphasized the rapid pace of change, noting that just twenty years ago, the idea of chikungunya and dengue in Europe would have been considered improbable. He attributes the current situation to the invasive mosquito and climate change.
Scientists are observing all-year-round activity of the tiger mosquito in southern Europe, which could eliminate the natural “firebreak” provided by cold winters and lead to larger, more frequent outbreaks. France, for example, saw a dramatic increase in cases, jumping from approximately 30 cases over a decade to over 800 in the last year alone, with many originating from outbreaks in French overseas territories like Réunion.
What Might Happen Next?
If warming trends continue, chikungunya could become more widespread throughout Europe. Local authorities may need to implement targeted control measures in specific locations and during months identified as high-risk for transmission. Increased surveillance for the Asian tiger mosquito and the virus itself will likely be necessary.
While vaccines for chikungunya exist, the most effective protection remains avoiding mosquito bites through the use of repellents and protective clothing. Community education regarding the removal of standing water – breeding grounds for mosquitoes – is also crucial.
Frequently Asked Questions
What are the symptoms of chikungunya?
The disease causes severe and prolonged joint pain, which is extremely debilitating. It can also be fatal in young children and older adults.
How is chikungunya spread?
Chikungunya is spread through the bite of infected Asian tiger mosquitoes. The virus enters the mosquito’s gut when it bites an infected person, then is present in the mosquito’s saliva, allowing it to infect the next person it bites.
What is the current situation in the UK?
There have not yet been any local transmissions of chikungunya reported in the UK, but a record 73 cases were reported between January and June 2025 among people who contracted the virus abroad.
As climate patterns continue to shift and the Asian tiger mosquito expands its range, understanding and preparing for the potential spread of chikungunya will be vital for protecting public health across Europe.