Serafin Gutierrez's main interests are virus ecology and evolution. Along mhis career, he has worked with different viral pathogens of insects, plants and vertebrates. Currently, his group works on various aspects of the ecology and evolution of arthropod-borne viruses, including the discovery of new zoonotic viruses. Moreover, his team explores the viral community or virome of insect vectors and its potential influence on arbovirus epidemiology. In this webinar, Serafin presented a collaborative work on West Nile virus (WNV) and Usutu virus (USUV), including teams involved in both human and veterinary health. These viruses follow a similar enzootic cycle involving mosquitoes and birds. However, they can also infect humans and other mammals, leading to severe disease. Their epidemiological situation may have shifted from irregular epidemics to endemicity in several European regions. This potential change requires confirmation, as it could have implications for risk assessment and surveillance strategies. To this end, the team has evaluated the prevalence and genetics of WNV and USUV in a cross-sectional study in humans, dogs, horses, birds and mosquitoes in the French Camargue area, between 2016 and 2020. Their findings support endemisation in the study region. Serafin also presented future research directions in his group.