In total 26 of 38 questionnaires sent out were completed and returned, resulting in a 68% response rate (Figure). Twenty one of the 30 EU/EEA countries, four out of the seven EU enlargement policy countries (Bosnia and Herzegovina, Kosovo1, Montenegro, and Serbia), and the UK replied to the questionnaire. In this section, if five or more countries gave a particular response, they are not listed individually. If a particular response was given by less than five countries, then they are individually named.
Figure 1. Overview of the responding countries
Over the period January 2020–May 2025, surveillance of Cu/ex mosquitoes was carried out in 17 of the 26 responding countries, while control measures were implemented in 12 countries (Figure). Among the nine countries that do not conduct Cu/ex surveillance, the reported reasons include: WNV is not considered a public or veterinary health concern (5/9 countries), it is not seen as contributing to outbreak response (Ireland), there is no legal framework supporting surveillance implementation (Ireland, Kosovo and Norway), and there are limited resources (5/9 countries). One country (Cyprus) mentioned that they are currently building the capacity to implement Cu/ex surveillance.
1 This designation is without prejudice to positions on status, and is in line with UNSCR 1244/1999 and the ICJ.