Spotted in China and reported to the World Health Organization (WHO) on December 31, 2019, the SARS-CoV-2 virus (which causes Covid-19 disease) has since infected tens of thousands of people (75,000 cases confirmed on February 20, 2020, for 2,130 deaths).
While it is impossible to know exactly how many people have been infected with the virus – in 80% of cases of infection, it is considered to be mild – studies published in February 2020 indicate different figures but go in the same direction. :
- the virus has a relatively low fatality rate (the disease seems fatal for 2% of infected people on average, but with differences according to age ), between 0.2% and 3.6%: below that of 2003 SARS,
- the index of contagiousness of the virus is also relatively low (between 1.5 and 3.5): for comparison, chickenpox is at 8.5 and measles at 9.
On the other hand, it is not because a virus has a low reproductive index and low lethality that it is harmless.