Knowledge, attitudes, practices regarding vector-borne diseases among adults in Switzerland: a cross-sectional survey

Background : Vector-borne diseases (VBDs) are an evolving public health concern in Switzerland, where endemic tick-borne infections coexist with emerging mosquito-borne threats linked to climate and ecological change. Public preparedness depends on population knowledge, risk perception, and preventive behaviour alongside institutional capacity. We assessed knowledge, attitudes, and practices (KAP) regarding VBDs among adults in the canton of Bern, interpreted alongside a complementary national stakeholder survey. Methods : We analysed a 2025 cross-sectional web-based survey embedded in the BEready cohort. After validity screening, we derived a latent knowledge score using a two-parameter logistic item response theory (IRT) model fitted to knowledge items. Multivariable linear regression examined associations between participant characteristics and latent knowledge. We identified KAP profiles through partitioning-around-medoids clustering based on block-weighted Gower dissimilarities. A parallel survey of cantonal and Liechtenstein authorities in human health, animal health, and environment departments provided institutional context. Results : Among 1,847 respondents, 1,337 met validity criteria. Knowledge was strongest for tick-related content: 98% matched tick-borne encephalitis to ticks, 87% did so for Lyme disease. Mosquito-borne knowledge was markedly weaker, with only 36% correctly classifying chikungunya and 43% West Nile fever as mosquito-borne, despite 53 % reporting at least weekly summer mosquito exposure. Tick checks were reported by 79% of participants versus 30% for mosquito standing-water removal. The IRT model indicated that mosquito-borne items were both hardest and most discriminating. Higher knowledge was associated with educational attainment, female sex, residence history, tick-bite frequency, and travel history, alongside a non-linear age effect peaking in mid-adulthood. Clustering identified six KAP profiles distinguishing knowledge gaps, low perceived relevance, and weak translation of knowledge into practice. The stakeholder survey (n=55) showed institutional engagement was considerably more developed for mosquito-borne than tick-borne diseases, although about half of authorities reported no dedicated human resources (49%) or budget (55%). Conclusion : Public knowledge and practice remain stronger for tick-borne than mosquito-borne diseases, despite frequent mosquito exposure, revealing a communication gap. Institutional preparedness shows the opposite pattern, being more developed for mosquito-borne threats. Public health strategies should sustain effective tick-prevention messaging while strengthening mosquito-borne disease communication, household source reduction, and support for community-level surveillance and control.