Noting a “continuation of the increase” in epidemic indicators “despite a shift” linked to the All Saints holidays, Public Health France underlined on Wednesday the “number of visits to the emergency room and hospitalizations for bronchiolitis very high and at levels higher than those observed at epidemic peaks for more than 10 years”.

The whole metropolis is affected, the northern part more strongly.

Faced with this black scenario, the Minister of Health François Braun announced in the Senate the triggering of an “ORSAN plan (organization of the response of the health system in exceptional health situations) specific to this epidemic, to further strengthen the means of ARS (regional health agencies) and allow the entire hospital to focus on this particularly acute problem today”.

“This does not mean that the white plan is triggered in all hospitals in France”, but only in a “limited number” at this stage, said the minister’s entourage.

The “white plan” contains organizational measures intended to deal with an exceptional health situation or increased activity of a hospital.

Common and highly contagious, bronchiolitis, most commonly caused by respiratory syncytial virus (RSV), causes babies to cough and have labored, rapid, wheezing breathing.

If it can worry parents, it is most of the time benign. But, in some cases, it may require a visit to the emergency room, or even hospitalization.

Nearly 6,900 children under the age of two went to the emergency room for bronchiolitis in mainland France from October 31 to November 6, a weekly increase of 7% – much less, however, than the previous increase (47%). Some 2,337 children were eventually hospitalized.

– “Rebound effect” –

“Before the Covid-19 pandemic, bronchiolitis epidemics were known for their great regularity, with a peak systematically reached around the 50th week of the year. The pandemic has upset this relative balance”, explains to AFP Pascal Crépey, epidemiologist at the School of Advanced Studies in Public Health in Rennes.

After a weaker circulation of the main virus causing bronchiolitis in 2020, the 2021 epidemic started in early October in France, in a context of end of confinements.

“The 2022 epidemic seems to be shaping up like that of last year for its start, but it is still difficult” to determine if the peak is approaching, according to Pascal Crépey.

On the Public Health France side, epidemiologist Sophie Vaux “expects it to continue to rise” and does not exclude that “the weekly rhythm goes up once the effect of the holidays has faded”.

How to explain this singular flight?

One of the hypotheses is a simultaneous circulation of viruses which, ordinarily, rather follow one another, according to Sophie Vaux. “The main cause of bronchiolitis and its most serious effects, RSV, circulates earlier. Other viruses that can cause bronchiolitis, such as rhinoviruses or metapneumoviruses, are also currently circulating,” she told AFP. AFP.

Another hypothesis: a “rebound effect” linked to a form of post-Covid “immune debt”, she adds. This “debt” could concern “children (larger than infants) and adults, including pregnant women who would have transmitted fewer antibodies capable of protecting their infants”.

In France, as in other countries, this early epidemic is bad news for hospital systems weakened by Covid.

This epidemic, “still in a rising wave”, “initially surprised the health system, which is forced to reorganize”, government spokesman Olivier Véran said on Sunday.

Since mid-September, 38 children in pediatric intensive care have been transferred from Ile-de-France to other regions.

Especially since bronchiolitis has only aggravated the crisis in pediatric emergencies, linked to unsatisfactory working conditions and a lack of staff.

France is not alone in difficulty. In the United States, a “tripledemia” of bronchiolitis, flu and Covid is raging during an early season that is testing hospitals.

Hope seems to be emerging on the treatment/vaccine side, after decades of research.

The European Union has approved a preventive treatment capable of preventing severe forms of bronchiolitis in all babies, the AstraZeneca and Sanofi groups, which are developing it, announced on Friday. These synthetic antibodies will not be available before the 2023 season.

Pfizer has reported positive results for an RSV vaccine, paving the way for future approval.