Assessing dengue knowledge, attitudes and preventive practices in France and Italy: A cross-sectional study using participatory surveillance cohorts.

The dengue virus, transmitted by Aedes mosquitoes, causes an estimated 100-390 million infections annually worldwide. With no treatment available, mitigation and prevention involve reducing mosquito breeding and limiting feeding opportunities. Due to changing climate conditions, Aedes mosquitoes are increasingly established in Europe causing more local cases. Thus, understanding population knowledge, attitudes, and practices in areas where dengue is an emerging threat is necessary for effective prevention. We designed a cross-sectional survey collecting knowledge, attitudes, and beliefs about dengue in the general population, leveraging the French and Italian 2024 cohorts of the participatory surveillance network InfluenzaNet. We analyzed pooled responses from 2,500 participants in mainland France and 404 in Italy. Via bias-adjusted (age, sex and education) logistic and ordinal regression, we examined determinants of awareness of dengue, knowledge of its characteristics, adoption of preventive measures, and vaccination willingness. Over 91% of included participants were aware of dengue as a disease, and 14.6% had sought information. Seeking information and concern levels were significant determinants of dengue knowledge, preventive measures adoption, and vaccination willingness. Better knowledge of dengue characteristics, vaccination status, residence in areas with detected autochthonous cases, and presence of comorbidities were associated with greater adoption of preventive measures. Living in rural areas was associated with lower knowledge and vaccination willingness but higher adoption of preventive measures. Finally, 0.4% of participants had received a dengue vaccine (not recommended to the general population), and 54.6% would accept a vaccine if offered. Low-risk perception was the most common reason for refusal. Our study highlights the interplay between knowledge, attitudes, behaviours, socio-demographic, individual and contextual characteristics of the participants related to dengue in a non-endemic context. Targeted communication strategies accounting for these factors are essential to enhance preparedness and outbreak prevention in regions where dengue represents an emerging threat.