For several weeks, indicators have shown an increased circulation of the coronavirus in France, while the situation remains relatively stable in hospitals. How to explain this paradox ? However, are we immune to a new runaway from the Covid-19 epidemic?
Update on the situation
More than 4,500 new positive coronavirus cases were detected daily Thursday and Friday, unpublished figures since May, according to Public Health France (SpF).
For several weeks, this indicator has been increasing steadily (+ 43% last week, + 39% the previous week), while the screening rate is “stable”, observes the health agency, which reports in its latest bulletin d ‘a doubling of cases every 17 days.
Other markers of the “strong progression of the circulation of the virus”: the number of new foci of grouped cases (“clusters”) is “still increasing” and the reproduction rate (called “R”) is around 1, 3 since the end of July. This number denotes the average number of people infected with each carrier of the virus. When it is above “1”, the epidemic develops.
Result: seven departments are now considered “high vulnerability” to the epidemic and 31 “moderate” vulnerability.
Reasons not to dramatize
The number of cases detected last week (around 16,800) is higher than it was in mid-March, when containment began. However, it is difficult to compare: few tests were carried out at the time, and mainly on patients with severe forms, whereas today nearly 700,000 tests are carried out per week and more than half of the positive tests concern people without no symptoms.
Another optimist’s argument: the number of new contaminations has been increasing for several weeks but we have not observed any notable change in the number of people hospitalized or in intensive care. Since the peak reached on April 8, with 7,148 patients in intensive care, this figure has continued to drop until the end of July and has changed little since (379 this weekend).
For epidemiologist Antoine Flahault, this is the essential. “We have no increase in hospitalizations or deaths, which would be a much more worrying alarm signal”. “We enjoy a wonderful summer respite in Western Europe,” he adds, while this is not the case elsewhere (Israel, South Africa or Australia).
More positive cases detected but no major impact on hospitals: the virus “seems to circulate preferentially for the moment in populations that are not very fragile, not very sensitive to serious forms of the infection: young populations or people who do not have no risk factor “, recently estimated the virologist Vincent Maréchal on France 2.
Perhaps because those under 65 have resumed their social interactions more than their elders, with less respect for barrier gestures (greeting without kissing, physical distance, hand washing, etc.), according to the latest surveys by health authorities.
“Behavior changes such as better hand hygiene and” physical distancing “mean that infected people are infected with” a lower viral dose than in the period before confinement, which results in a less severe disease “, also suggests Brendan Wren, professor at the London School of Hygiene and Tropical Medicine.
An article published recently in the journal Cell has also relaunched the hypothesis of a mutation of the virus which would have made it more contagious but less deadly. But many commentators point out that this strain of the virus carrying the mutation has been identified since April and was circulating in Europe during the first wave. They therefore consider that it is hardly credible that it is the cause of the lower mortality rate currently observed.
The points that worry
“The situation is worrying”, judges Renaud Piarroux, head of department at La Pitié-Salpêtrière (AP-HP), however. The more the number of new cases progresses, “the more the needs in tests, in laboratory samplers, in tracing increase”, and “the greater the risk of being in a situation where it will be difficult to identify all the cases” and where we will lose control of the virus, he explains.
For other doctors, the spread to populations at risk (elderly or presenting a factor of fragility such as diabetes or obesity) of the increased circulation of the virus is only a matter of time. “An increase” in the proportion of new cases, admittedly less strong than in other age groups, is already “observed in people over 65 years,” said SpF.
“The epidemic is starting again, that’s a pretty sure thing”
And even if the figures in hospitals have nothing to do with what they were in the spring, there is a “rising trend in new hospitalizations and admissions in intensive care”, warns the health agency.
New hospitalizations of patients with Covid-19 crossed the 1,000 mark last week against 780 the previous week, up for four weeks, and new intensive care admissions rose to 128, from 122 at the start of August and 105 at the end of July.
While he entered an average of 10 patients per day in intensive care in mid June-early July, “we have reached twenty” currently, underlines epidemiologist Catherine Hill. “The epidemic is starting again, that’s a pretty sure thing.” She deplores a testing policy that is still too focused on people with symptoms and their contact cases.
–
