Dengue cases in European travellers reached a record high in 2024. Learn what the numbers show, how imported cases relate to local outbreaks, and how to reduce your risk before travelling.
A Record Year for Imported Dengue
Dengue is a viral infection transmitted by Aedes mosquitoes. Most cases in Europe are imported by travellers returning from tropical regions. In 2024, the United Kingdom reported 904 imported dengue cases among returning travellers in England, Wales, and Northern Ireland, up from 631 in 2023, reaching the highest level since surveillance began in 2009. Most of these cases were linked to travel to southern and south-eastern Asia, according to the UK Health Security Agency. These figures reflect a wider European trend. The European Centre for Disease Prevention and Control recorded over 4,900 imported dengue cases in the European Union and European Economic Area in 2023, compared with 1,572 in 2022, a substantial increase. The 2024 figure was the highest number recorded since UK surveillance of dengue cases in travellers began in 2009.
Why Imported Cases Matter
Imported dengue cases are not just a personal health concern; they can seed local outbreaks. When a returning traveller is bitten by a local Aedes mosquito, the insect can become a vector, transmitting the virus to other people. The tiger mosquito, Aedes albopictus, is now self-sustaining in 13 European Union and European Economic Area countries, spreading further north, east, and west in Europe, as reported by the European Centre for Disease Prevention and Control. In mainland France, the enhanced surveillance bulletin for the summer of 2026 documented 8 autochthonous chikungunya episodes totalling 46 cases and 4 autochthonous dengue episodes totalling 6 cases, alongside 353 imported dengue and 126 imported chikungunya cases. These local clusters show that the presence of the vector and the arrival of infected travellers can trigger transmission far from the tropics.
The Global Dengue Landscape
The rise in imported cases tracks the epidemics that European travellers visit. As of September 2026, over two million dengue cases and more than 1,000 dengue-related deaths had been reported globally, according to the European Centre for Disease Prevention and Control monthly overview (ECDC). In the Americas, 1,658,783 cases were reported by week 35 (ending 30 August 2026), 57% fewer than in the same period of 2025, a fall from the peaks of 2024 and 2025 but not an end to transmission. In South-East Asia, Sri Lanka reported 100,127 cases as of 27 September, India 46,670 as of August, and Bangladesh 10,135 suspected cases in the week to 20 September. In the Western Pacific, Cambodia reported 85,920 cases as of 6 September, Malaysia 63,752 by week 34, and Vietnam 115,967 as of 6 September. These figures illustrate intense transmission in popular travel destinations.
A Changing European Risk
Climate change is making parts of Europe more suitable for invasive mosquitoes. The European Centre for Disease Prevention and Control states that climate change will largely impact the spread of mosquito-borne diseases in Europe by creating environmental conditions favourable for the establishment and growth of mosquito populations. Director Andrea Ammon is quoted as saying that Europe is already seeing how climate change is creating more favourable conditions for invasive mosquitoes to spread into previously unaffected areas. This is reflected in the spread of Aedes albopictus, which is moving north, east, and west. Locally acquired dengue in the European Union and European Economic Area rose to 130 cases in 2023, compared with 71 in 2022, and against a total of 73 cases in the ten years from 2010 to 2021.
How Travellers Can Reduce Risk
For travellers, simple steps can greatly reduce the risk of mosquito bites. The UK Health Security Agency advises using insect repellent, covering exposed skin, and sleeping under insecticide-treated bed nets. A travel health consultation is recommended 4 to 6 weeks before departure. In 2025, despite high travel volumes, imported dengue in England, Wales, and Northern Ireland fell to 344 cases from 904 in 2024, showing that preventive measures can be effective (UKHSA). However, other mosquito-borne infections rose: chikungunya increased by 43% to 160 cases, and Oropouche virus disease was reported for the first time (UKHSA). This underscores the need for vigilance not only against dengue but also against other emerging threats. Travellers should check the latest health advice for their destination.
Local Outbreaks in Europe
Even in mainland Europe, local outbreaks can occur. In France, the same 2026 bulletin reported 353 imported dengue cases and 126 imported chikungunya cases alongside 8 autochthonous chikungunya episodes totalling 46 cases and 4 autochthonous dengue episodes totalling 6 cases. These outbreaks occurred in Occitanie, Nouvelle-Aquitaine, and Ile-de-France for chikungunya, and in Occitanie, Nouvelle-Aquitaine, and Provence-Alpes-Cote d'Azur for dengue. This demonstrates that under the right conditions, local transmission can happen. However, such outbreaks remain limited and generally small. The European Centre for Disease Prevention and Control noted that in 2023, locally acquired dengue in the European Union and European Economic Area was 130 cases, compared with 71 in 2022, a substantial increase but still far below levels in tropical regions.
The Role of Surveillance and Public Health
Surveillance systems are crucial for tracking and responding to mosquito-borne diseases. The European Centre for Disease Prevention and Control publishes a monthly dengue overview that provides a global reference. In the United Kingdom, surveillance has been in place since 2009, allowing authorities to detect trends and issue timely advice. Enhanced surveillance in France during the mosquito season helps identify local transmission early. These systems enable public health bodies to inform travellers and the public, guide prevention measures, and prepare healthcare services. The figures also underscore the need for international cooperation, as the risk in Europe is directly linked to disease activity in tropical regions. These systems track disease trends and guide prevention advice and healthcare preparation.
Sources
- Worsening spread of mosquito-borne disease outbreaks in EU/EEA, according to latest ECDC figures: European Centre for Disease Prevention and Control
- Dengue worldwide overview, monthly update: European Centre for Disease Prevention and Control
- Imported dengue cases reach record high: UK Health Security Agency
- Travellers reminded to protect themselves against mosquito bites: UK Health Security Agency
- Chikungunya, dengue, Zika et West Nile en France hexagonale: bulletin de la surveillance renforcee du 2 septembre 2026: Sante publique France
- Travel-associated infections in England, Wales and Northern Ireland: 2025: UK Health Security Agency
This article is general information, not medical advice. Ask a doctor or pharmacist about your own health.