The EEID 2020 conference aims to bring together a very active scientific community working on infectious diseases and combining approaches from epidemiology, ecology and/or evolutionary biology. A wide range of biological systems (from plants to vertebrate hosts, from viruses to metazoan parasites) and methodological approaches (phenotypic, genomic, theoretical) will be discussed in order to confront and combine the expertise and skills of the conference participants. In addition to the fundamental contribution to our understanding of host-parasite interactions, this integrative approach has concrete implications for plant and animal health in agronomy.The organisation of EEID 2020 is a great opportunity to bring together researchers from different Montpellier units, in particular from the labex agro, who are working on EEID themes. Such an event will also allow numerous contacts to be made with a view to developing and enriching existing collaborations between the Montpellier scientific community in evolutionary sciences and ecology and the world leaders in the discipline. Given the importance of this conference, it will also contribute to the scientific influence of our Montpellier community.