New figures from prestigious medical research centre l’Institut Pasteur in Paris have given an update on the state of the virus in France, in the same week as confinement began to be lifted.
The study shows that the virus is circulating slightly more quickly than anticipated. Similarly, the number of people being admitted to intensive care, while still dropping, is higher than previously predicted.
The new figures are an update to the institute’s previous epidemiological study, published on March 21, by infectious diseases specialist Dr. Simon Cauchemez and team.
The numbers show that on Monday May 11 - the day of the start of deconfinement, at the start of this week - around 3,900 people probably contracted the virus (although the figure could vary from 2,600 to 6,300).
But in the previous model, researchers predicted that infection levels would be at only 1,300 per day by this date (a variation of 840 - 2,300).
Hospital figures also show that the number of people being admitted to intensive care is slightly higher than predicted for the current date, although still dropping considerably.
The researchers said: “The number of people admitted to intensive care each day rose from 700 at the end of March, to 66 on May 7; while hospital admissions declined from 3,600 to 357 over the same period.”
On Tuesday May 12, 92 people were admitted to intensive care, and 670 people were admitted to hospital. There were still 2,542 people in intensive care on the same date.
In comparison, researchers had predicted that intensive care numbers would be at only 10-45 admissions per day by now, and that there would be a total of just 1,370-1,900 Covid-19 patients in intensive care nationwide.
Yet, the number of people going into hospital and being admitted to intensive care is dropping overall.
Infection rate dropping
The rate of infection - defined as the number of people each infected person themselves goes on to infect - has also dropped considerably compared to before confinement.
The day before confinement was imposed (March 16), the figures suggest that the rate of infection was at 2.9 per person. This has now dropped (as of May 11) to 0.67 - a reduction of 77%.
The figures also initially suggested that just before confinement was imposed, around 270,000-770,000 people were being infected per day, but new analysis has since revised these numbers down, to between 150,000-390,000 per day just before confinement on March 17.
Testing capacity
The government has always predicted that there would be a spike in the number of daily infections after deconfinement, and said they were preparing for a rate of about 3,000 per day, as part of the new “test, trace and isolate” strategy implemented from May 11.
Health minister Olivier Véran said that the government would aim to undertake 700,000 Covid-19 PCR (polymerase chain reaction) tests per day from May 11, and based this figure on the number of predicted new daily infections, it said.
This was calculated based on 3,000 new infections, equating to an average of 25 tests per person, to account for all of their contacts.
But at the current rate of 3,900 infections per day, the number of necessary tests rises to 710,000 per day.
Immunity to infection?
The new data suggests that only 4.4% of the population has been affected by Covid-19 - although this figure rises to 9% in the Ile-de-France and Grand Est regions (which have accounted for 58% of total new infections since May 11).
The real picture of the epidemic - as opposed to statistical models or predictions - will only become clear as the weeks go on, experts have said.
Jean Castex, national coordinator of deconfinement, told l'Assemblée Nationale on Tuesday May 12: “Hypotheses vary depending on the observation of real-life cases of the epidemic.”
Public health research institute l’Institut National de la Santé et de la Recherche Médicale (Inserm) is currently completing a study into the blood results of 200,000 French people, in a bid to build a clearer picture of the percentage of the population that has already been infected.
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