214 - Mosquito control in response to local dengue transmission in Europe

Abstract: The Asian Tiger mosquito Aedes albopictus, which was almost absent from Europe 35 years ago, is now well established in 13 European countries. This highly invasive species is the only one which present both competence and vectorial capacity to transmit dengue, chikungunya or zika viruses in Western Europe. Although not endemic, these viruses are regularly imported by travellers during the summer season. With the introduction and expansion of Ae. albopictus, Europe now faces a new health challenge. The first outbreak of chikungunya in Italy in 2007 - with several hundred cases identified - sounded the alarm that Europe had ecological characteristics compatible with local, autochthonous transmission of these arboviruses. The occurrence of local cases in Croatia (dengue) and France (dengue and chikungunya) in 2010 confirmed the reality of this risk. The countries most at risk have set up entomological and epidemiological response plans to limit the risk of epidemics on their territories. During the 2010s, small outbreaks of dengue - of around 10 cases – were more and more regularly identified and controlled. Since 2022, the number of dengue cases in Europe has exploded, reaching almost 300 locally-acquired cases in 2024, mainly in Spain, Italy and France. Europe is now fully integrated into the global dengue epidemiology.The exceptional phenomena of the last three years foreshadow the future vector situation in Europe.The response strategy based on vector control applied since 2006 is presented, and its limits in the face of the ever-increasing expansion of Ae albopictus and the growing movement of infected travellers are discussed.