The challenge The number of emerging infectious disease (EID) events has been increasing in recent decades, many of them occurring in Europe. It has often been stated that climate change, and more generally environmental change, has been responsible for this increased EID incidence. Little scientific evidence was, however, available to support these statements as the biological and ecological mechanisms involved in disease emergence were poorly understood. In addition, the methodology and analysis chain needed to investigate disease upsurge had not been formally defined in the context of changing environment. Public-health agencies, therefore, had few tools to monitor environmental change, or assess/predict its possible effect on human health. Project objectives Vector-borne diseases, specifically those diseases caused by pathogens transmitted by arthropods (insects, ticks) or borne by rodents, were selected as EID models because they are highly sensitive to environmental changes. In this context, objectives were two-fold: 1. Assess the importance of environmental and socio-economic changes on emerging vector-borne diseases in Europe ant its surroundings, and develop quantitative, predictive models of disease emergence risk. 2. Identify and characterise the main ecosystems exposed to high risk of disease emergence at the European scale. viii CONTENTS Methodology Diseases were selected according to the vectors and hosts involved in their epidemiology: tick-borne encephalitis, haemorrhagic fever with renal syndrome (rodents), leishmaniasis (sandflies), West Nile and malaria (mosquitoes). Also, African sources of West Nile and Rift Valley fever viruses were studied to improve control for the benefit of African populations, and investigate the risk of introduction in Europe. EDEN has combined the understanding of disease epidemiology in a variety of environmental settings through a multidisciplinary approach to: _ Characterise the capacity of vectors and hosts to spread