[What are the determinants of viral outbreaks and is it possible to predict their emergence?].

The emergence of a viral disease most often results from an imbalance in the interaction between the infectious agent, the host and the environment. After the introduction phase of a viral disease in a territory or a given population and once the first chains of transmission occur, the spread of the disease or its sustainability are possible if the control measures are not implemented or are not sufficiently effective. If it is difficult to anticipate the occurrence and introduction of an emerging viral disease, the following three key elements must be strengthened to limit its impact: (1) anticipation and preparation; (2) research and (3) monitoring and surveillance. Finally, to guarantee that the measures taken are relevant and acceptable to the population, a multidisciplinary approach must be systematically relied upon and re-evaluated on a prospective basis.