Zoonotic viruses: how to monitor their emergence?

Zoonoses are responsible of more than two thirds of human viral infections. In addition, with increasing contacts between humans and the wildlife and the domestic fauna, the emergence and reemergence of zoonotic viruses is accelerating. The development and democratization of high-throughput sequencing tools and their application in metagenomics allow inventorying the viral communities of various reservoirs and vectors in order to detect the emergence of viruses before their transmission to humans. The prediction of future emerging zoonotic viruses is very difficult, if not impossible. However, the characterization of viral communities present in the different actors of zoonotic transmission cycle is a first step to evaluate potential risks of transmission to humans. In this article, we report a brief summary of the concepts of emergence and zoonoses before reviewing the current tools available to monitor their emergence.