Mosquito-borne diseases
Mosquito-borne diseases such as dengue fever, chikungunya fever, Zika virus infections and West Nile fever are a growing global concern and are also gaining importance in Europe. In Switzerland, the Confederation, the cantons and specialised agencies are monitoring developments and working together within the framework of the One Health approach to identify risks at an early stage and implement targeted measures to protect the population.
Mosquito-borne diseases are becoming increasingly relevant in Switzerland due to climate change and the presence of invasive mosquito species. Mosquitoes can transmit numerous infectious diseases, that thus far occurred mainly in subtropical and tropical regions, but are now increasingly being detected in parts of Europe.
In Switzerland, dengue fever, chikungunya fever and Zika virus infections are of particular concern, as these diseases can be transmitted from person to person through mosquitoes. As tiger mosquitoes, such as the Asian tiger mosquito (Aedes albopictus) which are capable of transmitting these diseases, are already present in parts of Switzerland, imported infections could potentially lead to further transmission. However, no locally acquired cases have been reported to date.
West Nile fever is also increasingly spreading across Europe and is transmitted by native mosquitoes of the genus Culex. In the Canton of Ticino, the first locally acquired human infection was confirmed in 2025. Unlike dengue, chikungunya and Zika viruses, the West Nile virus is not transmitted from person to person through mosquito bites.
Other mosquito-borne diseases, such as yellow fever and malaria, are also notifiable in Switzerland and are subject to surveillance. By contrast, local transmission of these diseases is not currently expected in Switzerland. However, these diseases remain relevant for people travelling to endemic areas.
Protection and prevention
People travelling to areas where dengue, chikungunya or Zika occur should protect themselves against mosquito bites, for example by wearing long clothing and using insect repellents as well as insect screens or mosquito nets. Anyone who develops symptoms such as fever, skin rash or joint pain during or after travel should seek medical advice. Informing the healthcare provider about the travel itinerary facilitates early diagnosis and helps to identify potential local transmission through tiger mosquitoes so that appropriate measures can be initiated. Further information can be found on the Travel and Mosquitoes webpage.
Prevention measures also include eliminating breeding sites of the Asian tiger mosquito. This species can breed in even the smallest collections of water, for example in flower pot saucers, watering cans, buckets, rain barrels or street drains. For more information on preventive measures, visit the FOEN Website on Mosquitoes (available in DE/FR/IT)
Measures to control mosquito-borne diseases in Switzerland
To reduce the risk of locally acquired transmission of dengue, chikungunya and Zika viruses, as well as West Nile virus, in Switzerland, action plans have been developed on behalf of the subsidiary body “One Health”. They are the result of close collaboration between the Confederation, the cantons and various research institutions. They are intended for the competent cantonal authorities and serve as a basis for developing their own prevention and control plans. The aim is to identify potential disease transmission at an early stage, respond rapidly and effectively prevent local outbreaks through a phased and harmonised approach. (see the “Documents” tab)
Further information
Further topics
Federal Office of Public Health FOPH
Schwarzenburgstrasse 157
Switzerland - 3003 Bern