Record number of mosquito-borne disease outbreaks in Europe: health agency

A culex tarsalis mosquito is seen in an undated image. (Steve Whyard)

Europe has registered a record number of outbreaks of mosquito-borne illnesses such as chikungunya and West Nile virus this year, the EU health agency said Wednesday, saying climate change was contributing to a “new normal”.

Europe is experiencing longer and more intense transmission seasons for mosquito-borne diseases, said the European Centre for Disease Prevention and Control (ECDC).

“This shift is driven by climatic and environmental factors such as rising temperatures, longer summer seasons, milder winters and changes in rainfall patterns -- conditions that combine to create a favourable environment for mosquitoes to thrive and transmit viruses,” it said in a statement.

Europe was entering a new phase where “longer, more widespread and more intense transmission of mosquito-borne diseases is becoming the new normal”, said ECDC director Pamela Rendi-Wagner.

The mosquito that can spread chikungunya virus, Aedes albopictus, is now established in 16 European countries and 369 regions, up from just 114 regions a decade ago, the ECDC said.

Europe has seen 27 chikungunya outbreaks so far in 2025, a new record for the continent.

For the first time, a locally acquired case was reported in France’s Alsace region, “an exceptional occurrence at this latitude, highlighting the continued northward expansion of the transmission risk”, the agency said.

As of August 13, eight European countries had reported 335 locally acquired human cases of West Nile virus infection and 19 deaths, with Italy being the country most affected by far, with 274 infections.

“As the mosquito-borne disease landscape evolves, more people in Europe will be at risk in the future,” said Celine Gossner, Head of Section for food-, water-, and vector-borne and zoonotic diseases at ECDC.

Prevention was more important than ever, both through coordinated public health action and personal protection measures, she said.

The ECDC called for individuals in affected areas to protect themselves against mosquito bites using mosquito repellent, wearing long sleeves and trousers, and using window screens and bed nets.