The flu epidemic in France is expected to increase the use of healthcare during the Christmas holidays with a potential "strong impact" on hospitals, and its peak is expected to occur at the turn of the year, according to unprecedented projections published Wednesday by Pasteur and Public Health France.
In a metropolis where all regions are experiencing an epidemic, the various indicators related to influenza continued to rise for all age groups from December 8 to 14, the 50th week of the year, according to the weekly report from the public health agency released on the same day.
For the first time, Pasteur and Public Health France are communicating forecasts on the dynamics of the flu epidemic in metropolitan France, at the national and regional level, over a four-week horizon, and on the probable period of occurrence of the peak.
Objective: to provide a tool for anticipating the trajectory of the epidemic to help health authorities and healthcare professionals.
The first version of this model "anticipates an increase in emergency room visits for flu-like symptoms in the next two weeks, followed by a decrease" in the first two weeks of 2026, notably due to the delayed effect of a decrease in transmission linked to school closures during the holidays, the two institutions summarized.
"The performance of the model can vary," noted Juliette Paireau, who works on the mathematical modeling of infectious diseases at Pasteur and SpF, during a press conference: "for seasons that resemble the past, the model performs best; for very different seasons, the model will have more difficulty anticipating the dynamics."
The peak of the flu epidemic is, at this stage, expected rather in the week of Christmas, with "15% chance that the peak will take place in week 51, 70% in week 52 and 12% in week 1".
But "great uncertainty" persists "about the magnitude of the peak," Juliette Paireau said.
Given the forecasts and "despite the high degree of uncertainty inherent in modelling influenza activity, it is likely that the use of influenza care will increase significantly over the next two weeks in all regions of mainland France, with a strong impact to be anticipated in hospitals during the end-of-year holiday period," warned Pasteur and SpF.
And, at this stage, we cannot rule out a resurgence of the epidemic after the Christmas holidays, as observed last year, or later in the season as in 2022-2023, according to the two institutions.
English 
French