The four regions named – Occitanie in the south west, Provence-Alpes-Côtes d'Azur in the south east, Pays-de- la-Loire in the west and the greater Paris Île-de-France region – have all seen high levels of flu-related hospital admissions in the past week.
Santé publique France in its weekly bulletin recorded 1,787 flu-related hospital visits in the week before Christmas, of which 160 resulted in the patient being admitted – a sharp rise from previous weeks.
“An increase in all the indicators, whether it be hospital and intensive care admissions or the number of consultations”, has been observed in these regions, Vincent Henouf, deputy director of the influenza reference centre at the Pasteur Institute, told BFMTV.
In 2018 flu caused 9,500 deaths in France.
The health agency says it is still not too late to get vaccinated against flu if you haven't already had the jab, which can be obtained from your doctor or from participating pharmacies.
Flu wasn't the only virus causing problems over the festive period.
The seasonal stomach flu virus, known as “gastro” in France was also affecting certain regions with the south west particularly badly hit as the map below shows.
The north east of France as well as the Pays-de-la-Loire in the centre and the region of Provence-Alpes-Côte d'Azur have also seen the spread of a virus that causes acute sickness and diarrhoea.
To avoid falling victim to the virus members of the public are advised to wash their hands regularly, especially after visiting the toilet.
The illness normally lasts for between 24 and 72 hours. Anyone struck down by acute sickness and diarrhoea is advised to stay well hydrated.