Emerging Infectious Diseases in Europe Driven by Climate Change

Climate change is reshaping the infectious-disease landscape in Europe by changing the environment that pathogens, vectors and hosts depend on. Europe has warmed faster than most other regions, producing record heat, longer warm seasons and more extreme precipitation events — conditions that expand habitat suitability for mosquitoes and ticks and lengthen transmission seasons for many pathogens.
Vector-borne diseases that were once sporadic or limited to southern latitudes are now appearing more widely. Mosquito species capable of transmitting dengue, chikungunya and West Nile virus (notably Aedes albopictus and, in some areas, Aedes aegypti) have extended their ranges into parts of southern and central Europe, while tick vectors (e.g., Ixodes spp.) are moving northward and to higher altitudes, increasing exposure to Lyme borreliosis and tick-borne encephalitis. These range shifts are tightly linked to warmer winters and milder summers that improve survival and reproduction of vectors.
Empirical evidence from recent seasons illustrates this trend. The 2022–2023 West Nile virus transmission seasons produced hundreds of locally acquired human cases across multiple EU/EEA countries, and 2023 saw one of the widest geographic circulations of West Nile in recent years — demonstrating that areas previously at low risk are now vulnerable to outbreaks. Concurrently, locally acquired dengue and chikungunya cases have been reported within the EU/EEA, signalling active autochthonous transmission rather than only travel-associated infections.
Climate models and epidemiological projections indicate that these patterns are likely to intensify: for example, regional projections estimate up to several-fold increases in West Nile virus risk by mid-century under high-emission scenarios, with substantial geographic heterogeneity. This implies not only higher incidence in currently affected regions but also emergence in new areas where public health systems may be less prepared.
Public health systems in Europe have strong surveillance and research capacity, but climate-driven infectious risks highlight important gaps: vector surveillance is uneven between countries; diagnostic awareness and laboratory capacity for tropical pathogens are limited in some settings; and adaptation policies must integrate climate, veterinary, entomological and human health data (the One Health approach). Effective responses therefore require coordinated surveillance, strengthened vector control, climate-informed risk mapping, and cross-sectoral planning — actions that are urgent because the climatic drivers are already in motion.
So yes — Europe’s microbes are booking themselves extended summer rentals. The technical reality is simple: warmer, wetter, or more variable weather creates ecological space for vectors and pathogens to spread; the policy reality is harder: translate surveillance into prevention before the disease maps redraw themselves.

References:

1. Semenza, J. C., & Paz, S. (2021). Climate change and infectious disease in Europe: impact, projection and adaptation. The Lancet Regional Health – Europe, 1, 100002. https://doi.org/10.1016/j.lanepe.2020.100002. thelancet.com
2. European Centre for Disease Prevention and Control (ECDC). (2024). Epidemiological update: West Nile virus transmission season in Europe, 2023. https://www.ecdc.europa.eu/en/news-events/epidemiological-update-west-nile-virus-transmission-season-europe-2023-0. ecdc.europa.eu
3. ECDC. (2024). Worsening spread of mosquito-borne disease outbreaks in EU/EEA according to latest ECDC figures. (News update). https://www.ecdc.europa.eu/en/news-events/worsening-spread-mosquito-borne-disease-outbreaks-eueea-according-latest-ecdc-figures. ecdc.europa.eu
4. World Health Organization Regional Office for Europe (WHO/Europe). (2023). Zero regrets: scaling up action on climate change in the WHO European Region (policy briefing). https://www.who.int/europe/publications/i/item/WHO-EURO-2023-3198-42956-69520. who.int+1