Influenza: map, 2023 epidemic, strain, duration, symptoms

[Mis à jour le 3 janvier 2023 à 10h57] The flu epidemic is still on the rise in France at the start of 2023. Public health France reports in its bulletin of December 28 a “continued increase in influenza indicators in all age groups and a very strong increase in hospitalizations in all age groups” in week 51 (December 19-25). All regions of France are in the epidemic phase. The regions Hauts-de-France, Ile-de-France, Normandy and Provence-Alpes-Côte d’Azur are the most affected regions. “The flu is progressing strongly. And the health system is under great tension. I therefore remain very vigilant“, already alerted François Braun, Minister of Health in the Sunday newspaper December 18. In this viral context, France must “redouble your efforts” in terms of vaccination, estimates the Organization for Economic Cooperation and Development (OECD), on December 5, 2022. The threat of a deadlier seasonal flu than in previous years (she was absent during the winter of 2020-2021), and the risk of excess mortality linked to viral co-infections, are to be feared, reports the Academy of Medicine. Must therefore be careful and absolutely respect barrier gestures (mask, ventilation, etc.). WHO recommends a vaccination rate of 75%. As much as “we have not had a strong flu epidemic for two years and therefore our overall immunity to the flu has probably waned“, warned Professor Brigitte Autran, president of Covars, on October 4 on RMC. What are the flu symptoms ? The incubation period? The disease duration ? Is she contagious ? What are the treatments (natural or medicinal) to heal quickly? When to get vaccinated? Our special file on the flu.

Epidemic 2022-2023: how many cases of influenza at the moment?

All indicators of influenza are in progress in all age groups according to the Public Health France bulletin of December 28, 2022. The incidence rate of consultations for flu syndrome per 100,000 inhabitants is 460, sharply increasing compared to the previous week (it was at 390, or +29% increase). This upward trend was observed in all age groups and the consultation rate for flu-like illness was the highest among 15-64 years old. Since the start of monitoring (week 40) in mainland France, 193 severe cases of flu were admitted to intensive care. Among them, 16 were between 0 and 4 years old, 16 between 5 and 14 years old, 79 were between 15 and 64 years old and 80 were 65 years old or older.

Flu epidemic map

According to Public Health France, as of December 28, 2022:

• Continued increase in influenza indicators in all age groups
• Very sharp increase in hospitalizations, particularly among 15-64 year olds
• All metropolitan areas in epidemic phase
• Majority circulation of A(H3N2) virus
• Overseas: Guadeloupe, Martinique, Guyana, Mayotte and Reunion in epidemic phase

Definition: what is a flu?

The flu is a acute respiratory infectiondue to a influenza virus, while an influenza-like illness can be caused by many other respiratory viruses like rhinovirus, respiratory syncytial virus, etc. Influenza viruses are mainly divided into two types: A and Bdividing themselves into two subtypes (A(H3N2) and A(H1N1) pdm09) or lineages (B/Victoria and B/Yamagata). Type A influenza viruses circulate in many animal species (ducks, chickens, pigs, horses, seals, etc.). Influenza viruses from B-type circulate mainly in humans. Viruses A and B cause seasonal epidemics in humans, but only type A viruses have been responsible for pandemics to date, points out Public Health France. In autumn 2022, the A(H3N2) virus circulates mainly in France.

What are typical flu symptoms?

Each year, flu epidemics can affect all age groups, but the most vulnerable people are the children under two years old, adults over 65 and people with certain chronic diseases. Early symptoms of the flu include:

• great fatigue,
• chills even when you are not cold,
• a dry, painful cough
• then comes the fever which can rise to more than 39°c,
• aches,
• headaches…

In all cases, in case of sudden aggravation or without improvement of the state 72 hours after the first symptomsit is essential see a doctor.

When to get the flu shot?

Vaccination is recommended for people at risk and healthcare professionals, and is the best way to protect against influenza and its complications. It is necessary allow approximately 15 days between vaccination and the time when the body is protected against the flu. No need to wait for the first cold weather or the start of the epidemic to get vaccinated.

How long does a flu last?

A hard flu between 3 and 7 days (5 days on average).

What is the incubation time for the flu?

“The incubation time (the time between the moment of illness and the appearance of symptoms) generally lasts between 24 and 48 hours, but it can be extended to 72 hoursrecalls Dr. Parneix. However, the patient is contagious, even before the appearance of symptoms and this, during an average period of 6 days.“

Is the flu contagious?

The flu is a contagious disease. The patient can transmit it “even before the onset of symptoms and during an average period of 6 days“ recalls our interlocutor.

To be infected with the flu virus, you must be in contact with someone who already has the flu. Contamination can occur in three ways:

• The first by airway : a sick person projects droplets of saliva into the air, when talking, coughing or sneezing. Millions of viruses are then found in the air, ready to be inhaled and contaminate you.
• The second, by close direct contact : a sick person shakes your hand or kisses you.
• Finally, contamination can occur through the contact with touched objects by a sick person, for example a doorknob or a telephone.

• Cough at the bend of the elbow and cover the nose when sneezing,
• Wash your hands with soap regularly throughout the day, especially after blowing your nose, coughing or sneezing.
• Blow your nose in a tissue and then throw it in the trash, ideally closed with a lid,
• Carry a surgical mask if you are sick and you have to go to a closed and public place, this prevents contaminating others.
• the hydroalcoholic gel is also practical, but in the long term it can dry out the hands.
• Finally, remember to air the rooms regularly, several times a day: you will thus eliminate stagnant viruses in the air, through sneezing and breathing.

Treatment: how to cure a flu?

In case of flu-like symptoms:

• Consult the doctor quickly. He or she will be able to make the diagnosis and prescribe the most appropriate medications.
• Take some paracetamol to reduce fever, aches and pains.
• The vitamin C is also sometimes recommended to combat fatigue. Similarly, certain foods are particularly recommended to better combat fatigue.
• If necessary, you can complete with a nasal decongestant and one cough suppressant for dry and stubborn coughs.
• Finally, it is necessary drink plenty and rest.

What are the natural treatments to relieve the flu?

Garlic, lemon, honey, thyme… Several natural solutions can help boost the immune defenses in the prevention or treatment of the flu.

What are the figures for the last flu epidemic (2021)?

According to the epidemiological update published in October 2022 by Santé Publique France, influenza viruses began to circulate in December 2021. The epidemic started in March, peaked nationally in early April and ended in late April, either 9 weeks of epidemic. No other influenza epidemic had reached its peak as late over the period 2009-2022. A co-circulation of A(H3N2) and A(H1N1) viruses was observed, with a diversity of viral strains detected. Its impact was moderate in the general population, but important in children under 15.

What should I do if my child catches the flu?

To prevent your child from contracting the flu virus, it is important to teach him how to blow his nose in a single-use tissue, to cover his nose to his mouth when sneezing or coughing. In any case, consult your pediatrician so that he can examine him and administer, depending on the case, the most appropriate treatment, especially against fever.

To limit the seasonal flu epidemic, it is essential to adopt simple preventive measures on a daily basis aimed at limiting the circulation of the flu virus, particularly in communities and on public transport where it is easily transmitted. For those around people with the flu, it is recommended to respect these few hygiene rules:

• Wash your hands regularly and systematically after each outing and each contact with the sick person.
• Avoid close contact with the person with the flu and in particular if you yourself are vulnerable or “at risk” (pregnant women, seniors, people suffering from a chronic illness or immunocompromised, young children, etc.)
• Wash yourself regularly hands with soap and water, or if you cannot do otherwise, with a hydro-alcoholic solution, especially after any contact with the patient and after each return home.
• Do not share objects such as glasses, cutlery and of course toothbrushes.
• Ventilate its interior every day between 10 and 15 minutes to renew the air and prevent the proliferation of viruses.
• Clean germ nests such as door handles, remote controls, phone screens…

Thank you to Dr Pierre Parneix, medical officer of health and hospital practitioner in public health (Bordeaux University Hospital).