Ecological drivers of arboviral disease risk: Vector-host interfaces in a Mediterranean wetland of Northeastern Spain

The rising incidence of arboviral diseases poses a public health challenge worldwide. However, local-scale interactions among vectors, hosts, and the environment remain poorly understood. In this study, we analyzed historical, multi-source data to assess pathogen transmission risk in a Mediterranean wetland of Northeastern Spain, examining mosquito vectors, avian hosts for West Nile virus (WNV), and human hosts for dengue, Zika, and chikungunya. Mosquito activity peaked between June and October. Aedes albopictus was predominant in urban areas, whereas Culex species were more prevalent in rural and natural environments. The relative abundance of passeriform and columbiform bird species influenced potential amplification and dilution phenomena in the WNV enzootic cycle. We developed a spatial risk index for WNV transmission by integrating vector abundance and avian community composition. High-risk areas were identified near urban edges, particularly adjacent to rice fields and wetlands where mosquitoes and reservoir hosts overlapped. For dengue, Zika, and chikungunya, the highest transmission risk was observed in late summer, coinciding with the phenological peak of Aedes albopictus and the importation of cases from endemic regions. Collectively, these findings highlight the value of fine-scale ecological indicators for guiding targeted mosquito surveillance and control strategies to effectively reduce the risk of arboviral transmission in vulnerable Mediterranean regions.