Covid cases are progressing in France at the end of the year, even if the epidemic is increasing less markedly than in previous weeks. The peak seems to be reached. However, we must remain cautious in this 9th epidemic wave.
[Mis à jour le 20 décembre 2022 à 12h00] After a lull of a few weeks, the Covid epidemic started to rise again in France, with an incidence, hospitalization and resuscitation rate increasingreports the bulletin of Public Health France dated November 24 2022. In its opinion of December 16, the Covars, which replaces the Scientific Council, evokes an “active resumption of Sars-Cov-2”, associated in particular with an increase in the circulation of the BQ.1.1 sub-variant from the Omicron BA.5 variant responsible for the last “wave “. This BQ.1.1 variant is now the majority (approximately 60% nationally), with no signal of increased pathogenicity, but coexists with persistence of the earlier BA.5 variant. The epidemic situation of COVID-19 remains relatively comparable to that of the two previous waves, with signals suggesting that the peak of infections could be reached, continues the Covars. Specialists speak of a 9th epidemic wave, in parallel with an epidemic of bronchiolitis and influenza this winter. The Covid epidemic is evolving in waves. To date, 9 waves are recorded between March 2020 and winter 2022marked by the influx of patients in hospital and intensive care. Return in dates on the different waves of the Covid epidemic in 2020, 2021 and 2022.
9th wave of Covid: fall-winter 2022-2023
After several weeks of decline, hospital indicators increased in the week of November 14 to 20. Public Health France therefore speaks of a “resumption of the circulation of SARS-CoV-2 on national territory” and of an “increase in hospital indicators” in its bulletin of November 24, 2022. A 9th wave is raging in France. She is marked by an increasing incidence rate, an increase in positivity rates and an upturn in new hospitalizations and critical care admissions. In an opinion published on December 16, Covars reports a resumption of the epidemic in France, associated in particular with:
► The increase in circulation of the BQ.1.1 sub-variant from the Omicron BA.5 variant. This BQ.1.1 variant is now the majority (about 60% nationally), with no signal of increased pathogenicity, but coexists with persistence of the earlier BA.5 variant,
► The increase in cases, observed in all territories including overseas territories, with reproduction numbers similar to those observed during the last 3 epidemic outbreaks due to BA.4 and BA.5
8th wave: September-November 2022
Specialists speak more of a rebound of the 7th wave rather than a real 8th wave
An 8th epidemic wave started in France in September 2022. This rebound in incidence in mainland France was linked to the resumption of social contacts and the sudden drop in temperatures (professional activities, reopening of schools) after the summer break, explained the Covars . Anne-Claude Crémieux, infectious disease specialist interviewed in the Journal du Dimanche indicates that a “endemic-type scenario, with new waves of infections, more marked in autumn or winter as for the flu or other respiratory viruses, seems (…) the most likely“.”This 8th wave is made of the same variant as the one that circulated during the summershe recalls this time at the microphone of France Inter October 10. Specialists speak more of a rebound of the 7th wave rather than a real 8th wave. You have to remember that we had the same phenomenon with the delta variant last year. There had been a rebound also in the fall of 2021.” This vague, carried by subvariants of OmicronBA4 and BA5 had less direct hospital impact than earlier waves. Here is the forecasts reported by the Covars, seized to issue its hypotheses to fight against the 8th wave of Covid
7th wave of Covid: July 2022
The 7th epidemic wave of Covid peaked in July 2022 and was carried by two sub-variants of Omicron BA.4 and BA.5. “Probably due to their ability to escape immunity acquired through infection and/or vaccination, especially if this has waned over time“, reports the European Center for Disease Control (ECDC) in a May 13 report. In mid-June, the average number of confirmed cases hovered around 40,000 per day.
6th wave of Covid: end of March – mid April 2022
Some epidemiologists have suggested a 6th wave, at the end of March 2022, with an incidence rate and a total number of positive cases which were going up. Nevertheless, this wave was smaller scale than previous waves (see curve below). According to figures from Public Health France, the number of cases gradually decreased around April 5 until reaching a plateau of around 20,000 new cases per day around May 20, 2022. the rise. The peak of the 6th wave was around the March 31, 2022.
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5th wave of Covid: November 2021 – February 2022
The fifth wave of the COVID-19 epidemic started in early November 2021. The incidence rate has increased sharply and exceeded the level reached in previous waves. Despite the increase in incidence observed in all age groups at the start of this 5th wave, the virus seems to have mainly circulated among the youngest. This wave first conveyed by the variant Deltawas then marked by the emergence of a new variant called Omicron. In this worrying context, the government has relied on a recall campaign. The incidence rate peaked around January 24, 2022 (with 3,800 positive cases per 100,000 population). The peak of hospitalizations was reached on February 7, 2022 with more than 33,000 people hospitalized. The curves then slowed down around mid-February. In March, we can say that France came out of the 5th wave.
4th wave of Covid: July-August 2021
On July 21, 2021, Prime Minister Jean Castex confirmed on TF1 that France had entered its fourth epidemic wave. At that date, the curve of hospitalizations was still low because we know that it takes on average 2 to 3 weeks for the increase in cases to affect the number of people hospitalized. The peak was reached in mid-August. The generalization of sanitary pass pushed the French to go to get vaccinated which made it possible to bring down the curve of hospitalizations. The peak of the 4th wave was reached at the mid-August 2021 (around August 12, 2021)
3rd wave of Covid: March-April 2021
After experiencing a decline from November 16, 2020, the epidemic is started to rise again in mid-March 2021, with an average of new cases per day of 50,000. “Yes the third wave is here and it is hitting us hard” alerted the Prime Minister, Jean Castex, before the National Assembly on April 1, 2021. Monday March 29, 2021, the number of people in intensive care exceeded that of the peak of the second wave in the fall. This is the highest number since April 22, 2020. The health situation is particularly critical in Ile-de-France where hospitals are saturated. The highest number of critical care admissions was reached on April 12, 2021 with 495 new admissions. The peak of the 3rd wave was reached on April 12, 2021 for hospitalizations and April 13 2021 for resuscitation.
2nd wave of Covid: September – November 2020
The Scientific Council alerted at the beginning of September 2020 to the occurrence at the end of that same month ofa second epidemic wave. “Circulation of the virus resumed during the summer of 2020 throughout France, particularly among young adults. The number of cases diagnosed each day reached 10,000 on September 1.“, he explained in a note of October 26. A drop in the figures was observed during the second half of September (on average 15,000 new infections per day). As of October 1, 2020, “there is an extremely rapid rise in the number of new caseswhich follows a general drop in temperatures (drop reaching 25°C for the maximum in places) which began between September 20 and 25 depending on the region“, continued the Scientific Council. The epidemic then progressed in France to reach in mid-November [autour du 15 novembre] a number of people hospitalized slightly higher than the peak in mid-April (about 32,000 people hospitalized each day between November 11 and 20). In mid-November, the epidemic is in decline. On December 14, 2020, the daily number of new cases hovers around 4,000. The peak of the 2nd wave was reached between 12 and 19 November 2020.
1st wave of Covid: March – May 2020
Since the first official cases recorded in France on January 24, 2020 by Public health Francethe numbers of new cases and new deaths from Covid-19 have increased dramatically increasing until the end of March. In other words, from the end of January to the end of March, France was in ascending phase. From April 3, 2020, the impact of the epidemic was major and “France was in a high plateau phase“indicated Jérôme Salomon, director general of health on April 10. The number of people hospitalized was the highest on April 14 (over 32,000) to drop gradually between April 20 and early June (around 15,000). Between June 15 and September 20, 2020, the number of hospitalized patients stabilized around 5,000 and the number of people in intensive care around 400: France was then in a low plateau phase. The numbers began to rise again in late August, leaving predict the start of a second wave. the first wave peak took place, according to the curves, between April 6 and 10, 2020.
Bell curve: characteristic of viral diseases?
For each of the waves, the epidemic curve appears to follow the bell curve (see curves above). The bell shape (also called curve of Gauss in mathematics) is typical of curves of evolution of an epidemic called “by propagation”, as is the case with most human-to-human diseases (viral diseases). If we analyze the epidemic curve of a viral disease, we always notice an ascending phase at the start of the epidemic, then a bell shape which corresponds at the peak of the epidemic, a stagnation in the number of new cases and finally, a downward phase, where the number of cases gradually decreases. For some scientists, this typical “bell” shape represents an indicator that would announce that the peak of the epidemic has been reached and that the disease is in a very decreasing phase.
Sources: Covid-19 epidemiological update, Public Health France // Geodès curves – Public Health France (hospital data) // Note from the Covid-19 Scientific Council: a second wave resulting in a critical health situation – October 26, 2020