Chikungunya virus, typically found in tropical and subtropical regions including Central and South America, the Caribbean, the Indian Ocean islands, South and Southeast Asia, and Africa, could soon spread to Europe and North America, a new study warns.
Scientists from Zhejiang Chinese Medical University in Hangzhou, China, say that climate change is creating ideal conditions for two mosquito vectors in major cities. 'Climate change affects chikungunya mainly by changing where its mosquito vectors can live,' explained Dr. Yang Wu, an author of the study. 'In our study, the Asian tiger mosquito was especially important, explaining more than 70% of the predicted distribution of the virus. Because this mosquito can tolerate cooler conditions better than the yellow fever mosquito, warming may allow it to establish in places that used to be too cold. When suitable mosquitoes become established, the chance of local chikungunya transmission increases.'
While the virus is rarely fatal, it can cause prolonged joint pain and disability. The word 'Chikungunya' means 'to become contorted' in the Kimakonde language. Chikungunya is a disease dating back to 1952, caused by a virus spread by Aedes mosquitoes. Despite approximately 33,000 cases so far this year, it remains one of the most neglected tropical diseases, according to the World Health Organisation.
Currently, most outbreaks occur in tropical and subtropical regions. However, by 2100, that could change. Dr. Ye Xu, another author, stated: 'At present, 139 countries or regions – accounting for 21.3% of the world's land area – are risk zones for the chikungunya virus. But we show that under climate change models, the virus will further expand northward into temperate regions, especially northeastern North America, central Europe, and East Asia.'
Future Hotspots Identified
The team modelled how the range of the yellow fever mosquito (Aedes aegypti) and the Asian tiger mosquito (Aedes albopictus) – the two known vectors – will change as temperatures rise. The models suggest that north-central Europe, northeastern North America, and eastern Asia are set to become 'future hotspots' for the virus.
'The public does not need to panic, but health systems should prepare early,' Dr. Xu said. 'Public health officials can act now by tracking Aedes mosquitoes, training doctors to recognize chikungunya quickly, strengthening mosquito control, and setting up rapid-response plans before outbreaks occur. These steps are especially important in temperate regions where the disease has not been a routine public-health concern. Limiting further global warming and investing in basic preparedness could reduce the chance that future expansion turns into large outbreaks.'
UK Cases on the Rise
While the study did not pinpoint the UK as a future hotspot, figures show cases are already rising. In 2024, there were 112 confirmed and probable chikungunya cases among travellers returning to England, Wales and Northern Ireland – nearly 1.5 times the number reported in 2023. According to the UK Health Security Agency (UKHSA), travel to India accounted for the majority, followed by Pakistan and Brazil. The UKHSA stated: 'There is currently no risk of onward transmission of chikungunya in the UK, as there is no evidence of invasive mosquito species established here. While invasive mosquitoes could currently establish in parts of the UK, climate change is likely to increase suitability for these species.'
What is Chikungunya?
Chikungunya is a disease caused by the chikungunya virus, transmitted to humans by infected mosquitoes. Large outbreaks and sporadic cases are reported mostly in the Americas, Asia and Africa, with occasional smaller outbreaks in Europe. Symptoms are similar to dengue and Zika, making misdiagnosis common. The disease causes fever and severe joint pain, often debilitating and prolonged, along with joint swelling, muscle pain, headache, nausea, fatigue and rash.
Two chikungunya vaccines have received regulatory approvals in several countries but are not yet widely available. There is no specific antiviral treatment; antipyretic and analgesic medications like paracetamol can alleviate symptoms. Severe symptoms and deaths are rare, usually occurring in young babies or elderly people with other health conditions.
