In December 2019, an outbreak of apparently viral pneumonia of unknown etiology emerged in the city of Wuhan, in the Chinese province of Hubei. A novel coronavirus (SARS-Cov2) is the pathogen responsible for this infectious respiratory disease called COVID-19 (CoronaVIrus Disease).
This situation raises many questions. How is the disease diagnosed? What is the period of contagiousness? How long is the incubation? Etc.
Here are the answers of Arnaud Fontanet of the Institut Pasteur.
From the Mooc of the Institut Pasteur "Emerging and reemerging Viruses".
https://www.pasteur.fr/fr/mooc-emerging-and-re-emerging-viruses