ANALYSIS
As the coronavirus has spread to around 30 countries, there has been a lot of conflicting information around the world. Several hundred scientists gathered Tuesday and Wednesday in Geneva, at the headquarters of the World Health Organization, to take stock of current knowledge about this epidemic, which has caused more than 1,100 deaths in China. Europe 1 tries to see more clearly on what we know, and what we ignore, on the coronavirus.
What is the incubation period?
According to a Chinese study, relayed by many media including Europe 1, the incubation period of the virus would be much longer, with an extension to 24 days. Except that this study has not been verified by other scientists. The vast majority of French researchers therefore believe that it is not reliable enough and that in reality the average incubation period remains well from 3 to 5 days, with a maximum of 14 days. The quarantine period for French people returning from China, for example, will remain at 14 days. There is no question, for the moment, of increasing it.
Can you be contagious without symptoms?
The question divides researchers. Arnaud Fontanet, epidemiologist at the Pasteur Institute, believes that it is possible to be contagious without symptoms. "There have been a few described cases that show it. Now is it 5%, 10%, is it something more common than we imagined? important to determine. The ability to identify patients, and isolate them quickly before they infect other people, will depend on when the infectiousness starts, "said the scientist. Clearly, WHO is concerned about possible carriers of the virus who ignore each other, and who risk spreading the epidemic.
Are stools a source of contamination?
The virus is transmitted when you cough, by spraying saliva or through physical contact. But at this stage, it is impossible to know if the stool is a source of contamination. Traces of the virus have been found in the stools of some patients, including in France. But we do not know if these are traces of a virus "dead", or still active and likely to contaminate. The issue is particularly important for less developed countries, where the wastewater drainage system is sometimes non-existent.
Can the return of spring stop the epidemic?
The President predicted on Monday that the coronavirus epidemic would likely go away in April due to the heat. "By April, or during the month of April, the heat, in general, kills this kind of virus," said Donald Trump. It is true that coronaviruses, like the flu, are often seasonal and thrive in winter, when the organisms are more fragile and the population lives mainly indoors with more promiscuity. It is also true that SARS, in 2003, had died out in June (SARS, severe acute respiratory syndrome, of the same family as the coronavirus, had killed 750 people worldwide, editor's note ).
But this COVID-19, the official name given by WHO to the coronavirus, is still a new virus. It is currently impossible to know how the virus will react to temperature changes. MERS (Middle East respiratory syndrome), for example, another of its cousins, is doing very well under the high temperatures of the Middle East.