Mosquito-borne diseases are an increasing threat due to global change, raising concerns even in areas where no cases had previously been recorded. This growing reality calls for more robust monitoring systems and coordinated responses, both in endemic and emerging regions. To address these challenges, scientists from various disciplines and countries are working together on international research projects, such as those coordinated by the Theoretical Ecology Department at CEAB-CSIC.

Climate change, the expansion of mosquito habitats and seasons, and changing bird migration patterns are driving the spread of diseases, such as West Nile fever, to new areas where no native cases have previously been reported. To address this problem, researchers from around the world are working collaboratively and interdisciplinarily within the framework of research projects such as IDAlert, E4Warning, and the Netherlands Pandemic and Disaster Preparedness Centre (PDPC).

In response to these challenges, a three-day meeting was organized at the CEAB-CSIC. This event served to discuss and deepen knowledge of the ecological routes of circulation and transmission of West Nile virus, to deepen collaboration and comparisons between different European wetlands, and to move toward more integrated and effective surveillance strategies that gather data on vectors and dynamics, thus strengthening early warning capabilities.

Wetlands as sentinels

The researchers, from countries like Germany and the Netherlands, have joined CEAB-CSIC scientists in fieldwork conducted in areas ideal for studying this issue, such as wetlands. These humid zones and their peri-urban surroundings are recognised as key sites for the surveillance of viruses like West Nile, as they bring together mosquitoes, birds (and other virus hosts), and humans. They are strategic study points for the E4Warning and IDAlert projects, offering an ideal setting to investigate the ecological drivers of arboviral circulation, as well as to test innovative tools like bird population characterisation and movement tracking systems, or “aspirators” to capture adult mosquitoes.

Besides visiting the Aiguamolls de l’Empordà, the international team also spent time at the Mar i Murtra Botanical Garden, another regular fieldwork site, this time for the IDAlert project.

Genetic techniques

The sessions offered hands-on insight into various aspects of the work done at CEAB-CSIC. One focus was the analysis of blood found inside female mosquitoes captured with devices such as aspirators. Genetic analysis of this blood allows researchers to identify which hosts the mosquitoes have bitten — revealing their usual “prey” and providing crucial information for risk prediction.

Another practical session focused on the use of FTA cards — small sampling devices placed in study areas to collect mosquito saliva — developed at Erasmus MC. These cards allow for the non-invasive detection of arboviruses using molecular techniques and represent a promising method for tracking viral circulation.

A meeting marked by diverse expertise

One of the key strengths of this gathering was the wide range of disciplines and professional backgrounds represented, which enabled a very productive exchange of ideas. The meeting brought together experts in epidemiological modelling, virology, vector ecology and environmental sciences, creating a vibrant forum for advancing integrated approaches to the surveillance of climate-sensitive diseases.

Among the participants were Joacim Rocklöv from Heidelberg University (Germany), coordinator of the European project IDAlert; Julian Heidecke, also from Heidelberg; Reina Sikkema from Erasmus MC (Netherlands) and representative of the Pandemic and Disaster Preparedness Center (PDPC); Maarten Schrama from Leiden University; Jordy Van der Veek, Tijmen Hartung and Erley Lizarazo. Local hosts from CEAB-CSIC included Frederic Bartumeus, co-director of Mosquito Alert, coordinator of E4Warning and partner of IDAlert, along with his team: Alex Richter-Boix, Catuxa Cerecedo-Iglesias, Nina Bogdanovic, Júlia Rodriguez-Grabalosa and Olatz San Sebastián; as well as Elisa Mora and Santi Escartín from the Mosquito Alert operations team.

During the workshop, participants worked on the development of scalable ecological and epidemiological risk indicators, combining traditional and novel technologies in the field — such as smart traps with automated mosquito species counting and identification, field-applied molecular techniques, and automated bird acoustic recordings. Together, they explored strategies to model and forecast the risk of West Nile virus and other climate-sensitive vector-borne diseases across Europe, harnessing the richness of data flows and diverse scientific perspectives.