Europe's dengue risk is up 297%. Public attention is going the other way.

By David Ogilvy, Chief Marketing Officer at Mosticare Global | Published 2026-05-07

The 2026 Lancet Countdown on Health and Climate Change Europe was released on Wednesday 22 April 2026 in Brussels. Halfway through it sits one of the most quotable European health figures of the season: between 2015 and 2024, the average climatic suitability for dengue outbreaks across the continent rose 297% compared with the 1981–2010 baseline. The risk of a European summer ending with locally transmitted dengue cases in Nice, Bologna, or Marseille has, in other words, nearly quadrupled in a single generation.

This is not a projection. It is a description of the recent past.

The figure carries weight because of where it comes from. The Lancet Countdown — whose Europe arm is co-directed by Professor Joacim Rocklöv at the University of Heidelberg and Professor Cathryn Tonne at the Barcelona Institute for Global Health (ISGlobal) — is the closest thing in climate science to an annual audit of state. Each November the global edition lands in The Lancet; each spring the regional editions follow. The 2026 European edition was produced by 70-plus contributing institutions, peer-reviewed, indicator-driven, and is generally treated by ministries of health as the authoritative tracker of how climate change is moving from forecast to fact.

The headline finding on vector-borne disease is precisely the kind of indicator that does not move easily. Climatic suitability is not calculated from anecdotal sightings or media reports. It is calculated from the temperature, humidity, and precipitation envelopes within which Aedes albopictus — the Asian tiger mosquito — and the dengue virus can complete their respective life cycles. When the indicator rises 297%, that means the calendar has lengthened, the territory has widened, and the mathematics of an outbreak season have all moved in the same direction at the same time.

The mosquito is doing what the data predicts. A. albopictus has been steadily colonising the European mainland since its first detection in Albania in the 1970s. By the 2000s it was in Italy, France, and Spain. In 2026 it is established in Germany, Austria, the Netherlands, Switzerland, Belgium, the Czech Republic, and — confirmed by the Observatoire de l'environnement en Bretagne earlier this spring — in coastal Brittany, a region long thought too cool and humid to host it. The Lancet Countdown notes that in the 1990s, regions where the tiger mosquito newly established could expect roughly twenty-five years to pass before the first locally transmitted outbreak. Today that window has compressed to under five years. France, which logged 805 autochthonous chikungunya cases in 2025 — an order of magnitude above the cumulative total of the previous decade — is a textbook example.

The report's authors are explicit that dengue is not the only vector-borne disease whose European calendar has been redrawn. Reported cases of West Nile virus, chikungunya, and Zika are all, the report says, increasing across the region. Take all four together and the combined climatic risk for arboviral outbreaks in Europe has roughly quadrupled since the 1981–2010 baseline. The Italian autochthonous dengue clusters of 2023, the French chikungunya season of 2025, and the steady drumbeat of West Nile cases across the Po Valley are not separate incidents. They are the same indicator expressed through different vectors.

Yet the report's most uncomfortable finding is not in the epidemiology section.

Of the 4,477 speeches given in the European Parliament during 2024, only 21 — fewer than half of one percent — addressed the link between climate change and human health. Public attention, as measured by media coverage, search interest, and political airtime, has plateaued or declined every year since 2022. "Across Europe, the health impacts of climate change are intensifying faster than our response is keeping up," Rocklöv said on the day of release. The line was not metaphor. It was a description of two opposing curves on the same chart.

Climate-and-health is, the Lancet's authors argue, suffering from the kind of attention deficit that affects steady-state risks. The mortality figures support the framing: the report attributes 62,000 heat-related deaths in Europe in 2024, with 99.6% of sub-country regions registering rising heat-attributable mortality. By the time the trend matures, the audience has often moved on.

What Europeans living in newly tiger-mosquito-occupied territory can do about this in 2026 is, despite the gravity of the report, not mysterious. ECDC, ANSES in France, the Istituto Superiore di Sanità in Italy, and the Robert Koch Institut in Germany converge on the same domestic checklist. Empty water from saucers, gutters, plant pots, and disused buckets weekly during the warm months. Replace standing water in pet bowls daily. Install fine mesh on windows and doors in known-establishment zones. Sleep under a treated net when travelling to active outbreak areas. Wide-spectrum chemical fogging — the headline approach in some Asian outbreak responses — is neither evidence-based at scale nor environmentally defensible in a European context. Source reduction at the household and street level remains the most cost-effective vector-control intervention in the published literature, and has been so since the 1980s.

This is the quiet editorial line of the 2026 Lancet Countdown: a temperate-zone mosquito problem that can be substantially reduced, but not eliminated, by routine adult behaviour, while the larger climate trajectory plays out over decades.

What to watch in the coming weeks is the surveillance signal. ECDC publishes its monthly chikungunya and West Nile updates from May. ANSES launched its 2026 vector-control season on 1 May. The European Centre for Disease Prevention and Control will issue its first comprehensive vector-borne disease seasonal forecast in late May. In Italy, the ISS dengue map refreshes weekly from June. Germany's RKI continues to update its citizen-science ZEMEKI dataset, which last year recorded Aedes albopictus in 25% of all submitted mosquito photographs, up from 12% in 2023. If the 2026 numbers track even halfway to the trajectory implied by the Lancet's 297%, the next twelve months will not lack for evidence.

What the report's authors would like to see, by their own admission, is for the evidence finally to be met by an attention curve that points in the same direction.

What we know

Sources cited

1. Rocklöv, J., Tonne, C., et al. The 2026 Europe report of the Lancet Countdown on health and climate change: narrowing window for decisive health action. The Lancet Public Health, 22 April 2026. https://www.thelancet.com/journals/lanpub/article/PIIS2468-2667(26)00025-3/fulltext
2. Lancet Countdown Europe — 2026 Report landing page. https://lancetcountdown.org/europe/2026-report/
3. Euronews Health — "The window to protect global health from climate change is rapidly closing, report warns." 22 April 2026. https://www.euronews.com/health/2026/04/22/lancet-report-2026
4. Observatoire de l'environnement en Bretagne — "Moustique tigre, dengue, Zika, chikungunya en Bretagne." Spring 2026. https://bretagne-environnement.fr/article/moustique-tigre-dengue-zika-chikungunyabretagne
5. franceinfo — "Trois questions sur la prolifération du moustique tigre après une année 2025 record en France." Spring 2026. https://www.franceinfo.fr/sante/maladie/chikungunya/trois-questions-sur-la-proliferation-du-moustique-tigre-apres-une-annee-2025-record-en-france_7987247.html
6. Robert Koch Institut — ZEMEKI citizen-science dataset, 2025 update. https://www.rki.de/DE/Themen/Infektionskrankheiten/Infektionskrankheiten-A-Z/Z/Zeckenuebertragene-Erkrankungen/ZEMEKI.html
7. European Centre for Disease Prevention and Control — Aedes albopictus current known distribution (June 2025). https://www.ecdc.europa.eu/en/publications-data/aedes-albopictus-current-known-distribution-june-2025