"What do you want to do, we are not going to remove the holidays!"
This ministerial adviser has fun, but Easter Monday upsets the indicators of the Covid19 epidemic.
This Thursday evening, it is the incidence rate which will, mechanically, drop suddenly.
This indicator corresponds to the number of cases tested positive over the past week, compared to a population of 100,000 inhabitants.
But these virological data are only known within three days.
The reason ?
Below this, too many test results would risk not having been taken into account, leading to an underestimation of the posted rate.
This Thursday evening, the incidence will therefore be communicated until Monday, that is to say the one relating to the week of Tuesday March 30 to Monday April 5.
The problem is that Monday was also a public holiday, Easter obligatory.
As a result, many screening sites (pharmacies, laboratories, etc.) were closed.
Like every Sunday, much fewer tests will have been carried out on Monday compared to the other days of the week, and especially compared to the previous Monday.
However, who says a lot less tests, mechanically says a lot less positive tests.
In calculating the most recent incidence rate, a “biased” Monday will therefore replace a “normal” Monday.
According to our calculations, the number displayed for the whole of France could drop to 330 ... against 404 Wednesday evening.
In Île-de-France, it could be 540 or 550, a drop of more than 100 points in one day.
Other data also impacted
People who would normally have been tested on Monday will no doubt have walked through the door of a laboratory or a pharmacy on Tuesday or Wednesday.
The gap could therefore be partially closed over the next few days, but that will not be enough.
And mechanically, next Thursday, the opposite effect will occur.
A "normal" Monday will replace a "biased" Monday, so the incidence will rise sharply at once.
DD LP /
This phenomenon is nothing new since it can be seen on every public holiday in recent months (November 11, Christmas, New Year).
The month of May promises to be particularly delicate, but fortunately two of the public holidays (the 1st and the 8th) fall on Saturdays, that is to say when the screening is already slowing down.
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This “public holiday effect” also impacts the other indicators, for slightly different reasons.
Hospitalizations, daily intensive care admissions and hospital deaths are counted by date of declaration.
However, on weekends, hospitals do not or partially fill in their data.
This is why we systematically observe lower figures on Saturdays and especially on Sundays before "catching up" on Monday, as indicated to us almost a year ago by Public Health France.
There, the numbers reported on Monday were also very low.
The averages over the past week calculated on Monday evening therefore fell suddenly.
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Finally, who says public holiday also says ... very few vaccinations.
A little more than 66,000 bites were made on Monday, slightly more than the day before but five times a month than a normal weekday.
The Ministry of Health said Tuesday noon to have tried to mobilize the regional health authorities (ARS) and the prefectures to ensure the opening of a minimum of vaccination centers.
Undoubtedly insufficient for Emmanuel Macron, who declared on March 23: “There is no public holiday, there is no weekend for vaccination.
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