[Covid-19, september 2020: fall storm warning]

Abstract

The resurgence of the Covid-19 epidemic in the fall of 2020 in France and in many countries around the world raises many questions. The situation of SARS-CoV-2 infection in France after the first epidemic wave in spring 2020 approximatively indicates more than 30,000 deaths, 3 to 4 millions people infected, 50% asymptomatic infections. These data encourage us to modify the initial perception of this infection, which was imagined to be benign, with massive, homogeneous and rapid distribution ("tsunamic"), and comprising a large majority of asymptomatic forms. This invites us to reassess the hypothesis of a major role of superspreaders in the spread of the infection, which would be more limited and discontinuous ("saltatory") than expected, as for SARS-CoV-1 and MERS-CoV. The role of viral load in the transmission and clinical expression of infection also needs to be assessed. To fight against the spread of the epidemic, generalized confinement a posteriori appears to have a disproportionate cost compared to its effectiveness, whereas the application of barrier gestures (breathing mask, hand hygiene, social distancing) should be promoted without any restriction, along with the diagnosis and temporary isolation of infected persons. While the Covid-19 epidemic is a medical challenge for human societies, it is also a moral challenge that they may not ignore.

Keywords: Covid-19; barrier gesture; respiratory viral disease; superspreader event; virological diagnosis.