Tropical Disease Threat Looms Over Europe: Chikungunya’s Expanding Reach
Chikungunya, a virus spread by infected mosquitoes, is traditionally associated with tropical and subtropical regions. Yet, a growing body of evidence suggests the disease is poised to become more prevalent across Europe, driven by climate change and the spread of the Asian tiger mosquito.
The Role of Climate Change and the Asian Tiger Mosquito
The Folkhälsomyndigheten (Swedish Public Health Agency) notes that chikungunya typically occurs in Central and South America, Africa, and Asia, with sporadic outbreaks in the US and Southern Europe. But recent research indicates this pattern is shifting. A new study reveals that the mosquitoes capable of carrying chikungunya are expanding their range due to rising temperatures.
Researchers have found that the lowest temperature at which chikungunya infections can occur is 2.5 degrees Celsius lower than previously estimated. This means that infection is now possible for more than six months of the year in several Southern European countries, including Spain, Portugal, Italy, and Greece. In Southeastern England, infections are now possible for two months annually, with further warming expected to extend this period.
A Rapidly Changing Landscape
Just twenty years ago, the idea of chikungunya and dengue fever becoming established in Europe seemed improbable. However, climate change and the invasive Asian tiger mosquito are rapidly altering the situation. France, for example, saw a dramatic increase in cases, reporting over 800 in 2023 compared to around 30 in the preceding decade.
The Asian tiger mosquito, Aedes albopictus, has been increasingly invading Europe in recent decades. It was first detected in Sweden in August 2023, with eggs found in plants brought from Spain. While the mosquito hasn’t yet established a permanent population in Sweden, experts believe it’s only a matter of time.
How Chikungunya Spreads and Its Symptoms
Chikungunya virus is transmitted to humans through the bite of infected Aedes mosquitoes. The virus cannot spread directly from person to person. Symptoms typically include fever, muscle and joint pain (often severe), headache, rash, and sometimes minor bleeding. While the disease is usually not fatal, long-term joint pain and disability can occur in some patients.
Outbreaks in Europe are often triggered by infected travelers returning from tropical areas where they were bitten by local mosquitoes. Historically, cold European winters limited the activity of the Asian tiger mosquito, but researchers are now observing year-round activity in Southern Europe.
Recent European Cases and Monitoring
During 2025, hundreds of cases were reported in France and Italy. In 2007, an outbreak in Northern Italy affected approximately 330 people, primarily tourists, marking the first documented spread of chikungunya within Europe. Italy was declared free of the virus in 2008, but the risk of re-emergence remains.
The ECDC (European Centre for Disease Prevention and Control) provides monthly epidemiological overviews of chikungunya transmission worldwide. As of January 31, 2026, 2,881 cases of chikungunya virus disease had been detected in 11 countries, excluding EU/EEA nations.
FAQ
Q: Can chikungunya be spread from person to person?
A: No, chikungunya is spread through the bite of infected mosquitoes, not direct contact between people.
Q: Is there a specific treatment for chikungunya?
A: There is no specific antiviral treatment. Care focuses on managing symptoms, particularly pain relief.
Q: What can I do to protect myself from chikungunya?
A: Employ mosquito repellent, wear long sleeves and pants, and eliminate standing water where mosquitoes can breed.
Q: Is chikungunya a serious disease?
A: While usually not fatal, chikungunya can cause debilitating joint pain that may persist for months or even years.
