Chikungunya Virus: Earlier Spread & Lower Temperature Threshold Warned by Study

A debilitating tropical virus, chikungunya, poses a greater threat to Europe than previously understood, with new research indicating it can spread in temperatures as low as 13 degrees Celsius (55 degrees Fahrenheit). This finding expands the potential geographic range and lengthens the transmission season for the virus, raising concerns for public health officials.

Chikungunya virus is transmitted to humans through the bite of infected mosquitoes, primarily the Asian tiger mosquito (Aedes albopictus). While rarely fatal, the illness causes severe and prolonged joint pain, which can be debilitating and persist for months or even years. The name “chikungunya” itself originates from a Tanzanian language and translates to “that which bends up,” describing the hunched posture often adopted by sufferers due to the intense joint pain.

The study, published in the Journal of Royal Society Interface and conducted by researchers at the UK Centre for Ecology & Hydrology (UKCEH), challenges previous assumptions about the temperature threshold for virus transmission. Earlier research suggested a minimum temperature of 16-18 degrees Celsius (61-64 degrees Fahrenheit) was required for the virus to incubate within the mosquito and be effectively transmitted. The new data demonstrates that transmission can occur at significantly lower temperatures, potentially extending the risk period by several months in warmer parts of Europe.

Researchers have created a risk map detailing the potential for chikungunya transmission across Europe, broken down into 10km square areas. The map highlights that the threat of virus transmission may last for a substantial portion of the year in southern European countries where the Asian tiger mosquito is already established. In 2025, France and Italy experienced record numbers of local chikungunya outbreaks, alongside increasing cases of dengue fever, also spread by the Asian tiger mosquito.

Currently, the risk of local transmission in the United Kingdom remains low, as the Asian tiger mosquito is only occasionally detected in southeast England and has not yet become established. However, the researchers warn that warming temperatures, driven by the climate crisis, could facilitate the mosquito’s establishment in the UK in the coming years, posing a future disease risk, particularly in the southeast.

The study’s findings are particularly concerning given the invasive nature of the Asian tiger mosquito. Originally from Southeast Asia, the mosquito has steadily expanded its range across Europe since its introduction in 2007. Rising temperatures are creating more favorable conditions for its survival and reproduction, allowing it to colonize new areas.

The upper temperature limit for transmission appears to be around 32 degrees Celsius (90 degrees Fahrenheit), with optimal transmission occurring around 26 degrees Celsius (79 degrees Fahrenheit). However, the lowered minimum temperature threshold is the most significant finding, as it dramatically expands the potential transmission window.

While a vaccine for chikungunya is now available – with Ixchiq and Vimkunya approved for use in the European Union – it is currently recommended primarily for travelers to high-risk regions. The European Centre for Disease Prevention and Control (ECDC) acknowledges that vector-borne diseases like chikungunya are becoming a “new reality” in Europe, and is actively monitoring the situation.

Symptoms of chikungunya typically include fever and severe joint pain, often accompanied by headache, nausea, fatigue, and a rash. While the acute phase of the illness usually lasts for a few days, the joint pain can persist for weeks, months, or even years in some individuals. The infection is rarely fatal, but can be dangerous for those with chronic illnesses, pregnant women, and infants.

Those who have recovered from chikungunya are generally considered to be immune to future infection. Public health officials emphasize the importance of mosquito control measures, such as eliminating standing water where mosquitoes breed, and using insect repellent, to reduce the risk of transmission.