Key points
- Dengue caused more than 2 million cases and more than 1,000 deaths from January to September 2026 (ECDC) — lower than the same period in 2025, but still widespread.
- Local transmission now happens in mainland Europe: 76 locally acquired dengue cases in Italy and 8 in France as of 28 October 2026 (ECDC), and 205 locally acquired chikungunya cases in France as of 26 October 2026 (Santé publique France).
- Both diseases are spread by Aedes mosquitoes. There is no specific treatment for chikungunya, so bite prevention is the protection.
- Florida, United States, recorded 524 locally acquired dengue cases in 2026 to 31 October — its largest in decades.
Direct answer: Dengue and chikungunya are mosquito-borne diseases spread by Aedes mosquitoes, and they are no longer tropical-only: local transmission now happens in mainland Europe. Dengue caused more than 2 million cases and more than 1,000 deaths from January to September 2026 (ECDC). Chikungunya has no specific treatment, so avoiding bites is the protection for both.
Dengue in 2026
Dengue is the most common mosquito-borne viral disease in the world. The European Centre for Disease Prevention and Control (ECDC) reports more than 2 million cases of dengue and more than 1,000 dengue-related deaths since the beginning of 2026 (overview as of September 2026) — a decrease compared with the same period in 2025 — and more than 2.5 million cases as of October 2026. In the Americas, 1,658,783 cases were reported to week 35 (30 August 2026), of which Brazil accounted for 1,294,963. A WHO global update of 9 October 2026 put the total at about 2.2 million cases and more than 1,100 deaths from January to August 2026 across 97 countries and territories.
Chikungunya in 2026
Chikungunya is spread by the same Aedes mosquitoes. In 2025 there were 502,264 cases (208,335 confirmed) and 186 deaths across 41 countries and territories; from January to March 2026 transmission was reported in 18 countries, mostly in the Americas, with Brazil and Bolivia accounting for 87% of regional cases. WHO’s Rapid Risk Assessment (version 2, 24 April 2026) rates the global risk as moderate, driven by the expanding range of Aedes mosquitoes, limited population immunity, no specific treatment, and limited vaccine use. ECDC’s public-health events page (5 November 2026) reports 271,223 chikungunya cases and 113 deaths in 26 countries from January to 30 September 2026.
Local transmission in Europe — and Florida
The change that matters most for readers in Europe is that these diseases are now acquired locally, not only brought back by travellers. As of 28 October 2026 (ECDC), locally acquired dengue stood at 76 cases in Italy and 8 in France, and locally acquired chikungunya at 205 cases in France as of 26 October 2026 (Santé publique France) and 1 in Italy. Aedes albopictus, the mosquito that carries both, is now established in 16 EU/EEA countries. In the United States, Florida recorded 524 locally acquired dengue cases in 2026 to the week ending 31 October — the largest in Florida in decades. Dengue must no longer be presented as “tropical only”.
Why the mosquitoes are spreading
WHO’s chikungunya risk assessment names climate- and travel-driven expansion of the mosquito’s range, with rainy seasons creating breeding conditions in standing water. The pattern is the same one behind dengue’s spread: warmer conditions and changing rainfall let Aedes mosquitoes live and breed in places that were previously too cool or too dry, and travel carries both the mosquitoes and the viruses between regions. The drivers explainer on this site covers the climate link in full.
How to avoid bites
The precautions are the same for both diseases, and they are the ones WHO and ECDC publish: use insect repellent on exposed skin; wear long sleeves and long trousers, especially at dawn and dusk; use window screens and bed nets where mosquitoes are present; and remove standing water around the home — in pots, tyres, buckets and gutters — where Aedes mosquitoes breed. Check travel-health advice before visiting an affected area, and if you become ill after travel to an affected area, tell a health professional where you have been. There is no specific treatment for chikungunya, so prevention and early care-seeking matter more than for most infections.
Frequently asked questions
Can you catch dengue in Europe now?
Yes — locally acquired cases now occur in mainland Europe. Italy reported 76 and France 8 locally acquired dengue cases as of 28 October 2026 (ECDC).
Is there a treatment for chikungunya?
No specific treatment exists. Prevention through mosquito-bite avoidance, and early care-seeking if ill after travel, are what WHO and ECDC point to.
How do I avoid mosquito bites?
Use repellent, wear long sleeves and trousers, use screens and nets, and remove standing water where mosquitoes breed — the same precautions for both diseases.