Comparing Aedes-borne disease surveillance systems in Southern Europe: France, Italy and Portugal

Introduction Colonization by the Aedes albopictus vector, alongside rising autochthonous dengue cases in France and Italy and imported dengue cases in Portugal reflect the emergent risk of Aedes-borne diseases in Southern Europe. In view of improving surveillance, preparedness, and response against Aedes-borne diseases in Europe, we aimed to systematically describe and compare the respective surveillance systems and response measures in place across France, Italy, and Portugal. Methods We employed a benchmarking analysis using a comprehensive set of surveillance system descriptors based on the ECDC document “Data quality monitoring and surveillance system evaluation”. We collected data from key-informant interviews, national guidelines and literature, and ensured data collection harmonization through a consensus decision-making process. Results Each country has an integrated surveillance system for Aedes-borne diseases. The 3 countries share similarities in surveillance type (passive, compulsory, comprehensive, year-round operating systems), geographic coverage (national), case definitions (adapted EU case definitions), and notification processes. France also practices active surveillance and Italy and Portugal event-based surveillance to complement routine surveillance. Common response measures include visiting affected areas, active case-finding, and blood safety measures. France and Italy responses largely focus on vector control, while Italy and Portugal monitor pathogens in vectors. Conclusions Surveillance systems in France, Italy, and Portugal are similar, while their response measures vary, likely reflecting different epidemiological and entomological context. Implementation of harmonised, risk-based surveillance systems across southern Europe and enhanced cross-border collaboration may improve preparedness, control and response to Aedes-borne diseases.