Executive summary

Europe is experiencing longer and more intense transmission seasons for mosquito-borne diseases, including for West Nile virus (WNV) infection as well as dengue and chikungunya virus disease. These developments increase the need for sustained mosquito surveillance and timely, effective control measures, but capacity and organisation vary across countries. This report describes how mosquito surveillance and control for Culex mosquitoes (vectors of WNV) and invasive Aedes mosquitoes are organised across EU/EEA countries, EU enlargement policy countries and the United Kingdom (UK), and identifies what is needed to strengthen preparedness and response.

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 Cu/ex (vectors of WNV) was conducted in 17 countries, with control measures implemented in 12. Activities vary considerably across countries and are often constrained by short-term 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.

The survey results show that sustainable mosquito surveillance and control across Europe continues to face structural and operational challenges. Many programmes remain dependent on short-term funding and external support, and the integration of entomological expertise into public health systems varies across countries. The key findings are:

• Long-term investment, training, and coordination at the European level are important factors influencing vector surveillance and control within countries. Regular exchange and collaboration between Member States is important for sharing good practice, addressing common challenges, supporting coordinated responses, and strengthening preparedness for outbreaks and unusual vector-borne disease events, including cross-border mobilisation of expertise and resources.
• The effectiveness of surveillance and control activities are influenced by the clarity of roles and responsibilities and the level of coordination between national agencies, local authorities, and other stakeholders. The implementation of a comprehensive One Health approach can be an important aspect of coordination.
• Limited availability or cost-benefit analyses for vector surveillance and control activities is a constraint for evidence-based decision-making and resource allocation. Additional challenges are in the areas of data integration, systematic evaluation of control measures, and establishing a stronger evidence base linking vector abundance to disease transmission risk.
• There are variabilities in data management approaches, surveillance and control objectives, operational guidance, and the uptake of innovative tools. There is a need for measurable control targets, updated guidance, and environmentally responsible approaches to vector surveillance and control.
• There is a need for capacity-building among entomologists and professionals involved in surveillance and control activities at the local level. Continuous training and access to practical training materials are important for maintaining and strengthening competencies.
• Awareness of legal and regulatory frameworks, such as the EU Biocidal Products Regulation, is important to shape the implementation of vector surveillance and control in countries. There are both opportunities and limitations associated with the current regulatory environment, including variations in implementation across countries.
• There are differences in laboratory and field capacities across Member States. Access to technical expertise, harmonised methodologies, and support for vector identification, pathogen detection, and professional training are important components of effective surveillance and control systems.
• Insecticide or biocide resistance was included among the surveillance indicators by some respondents, and the broader questionnaire findings indicate that understanding resistance patterns is relevant for planning control activities.