The annual epidemic of bronchiolitis, which mainly affects babies, has now spread to most of the French metropolis after accelerating in recent days, the public health agency announced on Wednesday. During the week ending November 5, “activity linked to bronchiolitis was significantly increasing in France,” summarizes a weekly report from Public Health France.

Four new regions (Hauts-de-France, Bourgogne-Franche-Comté, Nouvelle-Aquitaine and Occitanie) are now considered in the epidemic phase, which brings the number of metropolitan regions in this situation to ten. Of the remaining three, Auvergne-Rhône-Alpes and Provence-Alpes-Côte d’Azur are in the pre-epidemic phase and only Corsica is still spared. Overseas, Guadeloupe, Martinique and Guyana remain affected by the epidemic.

Bronchiolitis, caused primarily by respiratory syncytial virus (RSV), causes breathing difficulties in babies. Generally not serious, it can nevertheless lead to visits to the emergency room and hospitalizations. Last year, it was the cause of an unprecedented epidemic in more than ten years, sending tens of thousands of infants to hospital.

The epidemic is currently less than at the same time in 2022 but several indicators – consultations with private doctors, visits to the emergency room – accelerated last week to return to the already high level of 2021.

One of the big questions is the effect that a new preventive treatment, Sanofi’s Beyfortus, will have. Initially offered to all babies born since February, it is currently reserved for maternity wards, pending new stocks.

» READ ALSO – Bronchiolitis: victim of its success, Beyfortus is partly reserved for maternity wards

Public Health France has also given an assessment of two other diseases: Covid, in a declining phase, and seasonal flu, still limited to a few sporadic cases in mainland France while awaiting the inevitable annual epidemic.

Only Reunion Island and now Mayotte, in a special situation because they are subject to a reverse climate in the Southern Hemisphere, are already in the epidemic phase.