Paris (AFP)
The coronavirus, planetary apocalypse or trifle on which there is too much hype? Neither one, the experts answer this question which torments the general public: the risks, very real, weigh on the most fragile and on the hospitals which must avoid being overwhelmed.
- Who is most at risk?
Out of nearly 45,000 confirmed cases, the average mortality rate is 2.3%. But there are no deaths among children under the age of 10. Up to the age of 39, the mortality rate remains very low, at 0.2%, then drops to 0.4% in those in their forties, 1.3% in those aged 50-59, 3.6% in those aged 60- 69 years and 8% in the 70-79 age group.
People over the age of 80 are most at risk with a death rate of 14.8%.
"The problem is that when we talk about a death linked to the coronavirus, we almost never specify the reason why he died", said AFP Michel Cymes, doctor and TV host very popular in France.
"When someone 85 years old dies of coronavirus, it is not the coronavirus that kills him", but more often "the complications which reach organs which were not in good condition", he adds.
Another risk factor: having a chronic disease (respiratory failure, heart disease, history of stroke, cancer ...).
But the millions of people who suffer from these diseases should not panic.
For French professor Jean-Christophe Lucet, the risk concerns above all patients suffering from severe forms of these diseases. "We must be extremely clear" on this point, he said to AFP.
"The patient who has diabetes, the patient who has high blood pressure, these are patients who are not patients at risk," he reassures. "Patients at risk are those with severe heart disease, severe respiratory disease, such as advanced chronic obstructive pulmonary disease (COPD)."
- How many deaths can we expect?
More deadly than the seasonal flu, but less virulent than previous epidemics linked to a coronavirus: this is where the dangerousness of Covid-19 seems to lie, even if its mortality rate is not yet known precisely.
According to the February 24 study, the disease is mild in 80.9% of cases, "serious" in 13.8% of cases and "critical" in 4.7% of cases.
At this stage, 3.4% of the confirmed positive patients in the world died. But out of some 100,000 positive cases in total, more than half are already cured, according to the American University Johns Hopkins, which keeps a daily count.
The danger of a disease depends not only on the absolute death rate, but also on its ability to spread more or less widely.
"Even if only 3% of cases die, it can make significant figures if 30% or 60% of a population is infected," said Dr. Simon Cauchemez, of the Institut Pasteur in Paris.
"We are not all going to die: in the worst scenario, 0.4% of Belgians will die, the vast majority in the over 80s. Stop the psychosis", wrote this week on his blog the Belgian doctor Philippe Devos, in a risk analysis titled "Coronavirus: Armageddon or hogwash?"
- Will hospitals be overwhelmed?
This is the main danger of the current epidemic.
While the number of cases is increasing everywhere, the challenge is "not to saturate the hospitalization capacities of health establishments and (...) reserve the resources of health establishments for the most serious cases", according to a guide from the French Ministry of Health intended for carers.
As the number of cases increases, patients with a mild form of Covid-19 are no longer hospitalized but stay at home. Similarly, non-emergency hospitalizations are postponed to make way for the patients most affected by Covid-19.
If the hospital becomes saturated, "there is a big risk of going up to (...) 33,150 dead on 11 million inhabitants (0.3% of the Belgian population who dies). It is + little + (we will not not all die as we sometimes hear it) but still 100 times more than the number of road fatalities each year, "writes Dr. Devos.
The other priority is to avoid caregivers being themselves contaminated in numbers, which would make it even more difficult to care for the sick.
If these questions are already crucial in rich countries, they are even more acute in poor countries.
- What transmission, what symptoms?
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 avoid contagion, health authorities stress the importance of barrier measures: avoid shaking hands and kissing, washing hands frequently, coughing or sneezing in the crook of one's elbow or in a disposable handkerchief , wear a mask if you are sick ...
The most common symptoms "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, and management involves treating the symptoms. However, some patients are administered antivirals or other experimental treatments, the effectiveness of which is being evaluated.
- What about domestic animals?
The case of a dog tested "weakly positive" in Hong Kong, when his owner was himself infected, raised questions about human-animal infections.
But scientists insist that this case is isolated and that no conclusions can be drawn from it.
"You have to differentiate between a real infection and simply detecting the presence of the virus," said Professor Jonathan Ball of the English University of Nottingham.
"It requires knowing more, but don't panic," he adds. "I doubt that this dog can transmit the virus to another dog or to a man, because of the low level of virus detected. the real driver of the epidemic is human-to-human transmission. "
© 2020 AFP