Researchers are tracking the epidemic caused by the new coronavirus that has appeared in China, although many unknowns remain.
1. How deadly is coronavirus and who is most likely to die from it?
More deadly than seasonal flu, but less virulent than previous epidemics linked to a coronavirus: this seems to be the danger of the new Covid-19, even if its mortality rate is not yet known with precision.
According to the latest WHO figures this Saturday, 2,348 deaths were recorded out of 76,392 confirmed cases in mainland China (or 3.07%). Outside this country, WHO recorded 11 deaths for some 1,400 confirmed cases of contamination in 28 countries and territories.
The China Center for Disease Control and Prevention this week released a study of 72,314 confirmed, suspect, clinically diagnosed and asymptomatic cases of viral pneumonia reported on February 11. It is the most important since the beginning of the epidemic and according to its results the disease is mild in 80.9% of cases, “serious” in 13.8% of cases and “critical” in 4.7 % of cases.
The case fatality rate increases with age and those over 80 are the most at risk, with mortality of 14.8%. Patients already suffering from cardiovascular diseases are the most threatened by a fatal outcome, ahead of diabetics or people suffering from chronic respiratory diseases or hypertension.
However, overall estimates of mortality rates should be taken with caution as it is not known how many people are actually infected.
2. Is coronavirus very contagious? How much is there a risk of being contaminated?
Specialists seem to agree that each patient would infect between 2 and 3 people (the so-called “basic reproduction rate” of the disease, or R0). It’s more than flu (1,3), significantly less than measles (more than 12), and comparable to SARS (3).
But some warn about a possible underestimation of the number of cases. For example, a Friday study by researchers at the Center for Infectious Diseases at Imperial College London “estimates that about two-thirds of Covid-19 cases from China have gone undetected globally, potentially resulting in chains multiple undetected of human transmission outside China “.
WHO boss Tedros Adhanom Ghebreyesus said on Friday that he was “concerned” about “the number of cases with no clear epidemiological link, such as travel history or contact with a confirmed case”.
One of the concerns could be asymptomatic cases, with infected patients showing no signs of the disease. The incubation period, estimated according to studies between two and 10 days, has led to fixing the observation or quarantine period at 14 days for suspect cases and returnees.
3. How is coronavirus transmitted?
The virus is mainly transmitted by respiratory route and by physical contact. Transmission by respiratory route occurs in the droplets of saliva expelled by the patient, for example when he coughs. Scientists estimate that this requires a close contact distance (about one meter).
To guard against contamination, the health authorities insist on the importance of barrier measures: wash your hands frequently, cough or sneeze in the crook of your elbow or in a disposable handkerchief, wear a mask if you are sick. .. Furthermore, diarrhea could be a secondary route of transmission.
4. What are the symptoms of coronavirus and how to treat them?
“The most common include respiratory problems, fever, cough, shortness of breath and difficulty breathing,” says WHO. “In the most severe cases, the infection can lead to pneumonia, severe acute respiratory syndrome, kidney failure, and even death.”
There is no vaccine or medication for the coronavirus, and management is to treat the symptoms. However, some patients are administered antivirals, the effectiveness of which is being evaluated.
5. What is the origin of the epidemic?
The new coronavirus may have been born in bats, but scientists believe it went through another species before being transmitted to humans.
Chinese researchers have said that this intermediate animal could be the pangolin, a small mammal with scales in danger of extinction. The international scientific community has deemed this hypothesis plausible, but it will have to be verified.
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