Surveillance and control of Culex mosquitoes and Aedes invasive mosquitoes in Europe: questionnaire findings on current practice and needs

The information on the surveillance and control of Culex mosquitoes and Aedes invasive mosquitoes was collected through an online questionnaire using EUSurvey. The survey was sent to the ECDC Operational Contact Points (OCPs) for Entomology from 30 EU/EEA countries, Contact Points for Operations (CPOs) of seven EU enlargement policy countries, and the UK contact point. In total, 26 out of 38 (68%) questionnaires sent out were completed and returned. Twenty one of the 30 EU/EEA countries, four out of the seven EU enlargement policy countries, and the UK replied to the questionnaire. 

Between 2020 and 2025, surveillance of Culex (vectors of WNV) was conducted in 17 countries, with control measures implemented in 12. Activities vary considerably across countries and are often constrained by shortterm funding and limited long-term planning. Adult mosquito control using biocides is common. In the same period (2020—2025), surveillance for Aedes invasive mosquitoes was carried out in 20 countries, with control activities in 17. Approaches differ widely, with preventive and elimination measures targeting immature stages through a mix of biocidal and non-biocidal tools, often supported by social mobilisation. However, reactive control remains largely ad hoc, typically focused on adult mosquitoes, and long-term funding and elimination strategies are often lacking. The organisation and execution of surveillance and control activities varies considerably between countries, depending on national structures and responsibilities which can explain why in some countries, the national authorities are in charge, and in others, it is the regional or even local authorities.