What are the symptoms and Duration of the Flu?

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After the Ile-de-France, the flu spreads throughout metropolitan France in mid-December. Every year, the influenza epidemic causes annoying symptoms in millions of people, but also significant complications in many thousands. Doctissimo presents the signs of this viral disease, as well as its average duration.

Influenza-like symptoms vs. true flu symptoms
Duration of incubation, contagion, and recovery of influenza
Vaccination against influenza
Treatment of flu
symptômes grippe

Influenza is abundantly described in older medical books. As such, it is one of the oldest viral diseases. However, there is sometimes a tendency to use the term flu for a set of diseases that is not the flu virus, but a simple flu condition.

Influenza-like symptoms vs. true flu symptoms
Symptoms of influenza (or flu-like illness)
Several features distinguish the flu syndrome from the true flu. The symptoms of ILI are often transient and of moderate intensity. Those responsible for these “false flu” are syncytial respiratory viruses (SRV), parainfluenza viruses, adenoviruses, rhinoviruses, enteroviruses, coronaviruses …

Symptoms of true flu, viral and seasonal
On the other hand, real influenza, seasonal and viral, is characterized by symptoms of a strong intensity occurring suddenly :

An intense fever (around 39 ° C);
Intense fatigue (asthenia);
Headaches (headaches);
Aches and pains (diffuse muscular and articular pains);
Sometimes a cough and nasal congestion .
Far from being as harmless as its counterparts, the influenza virus remains in France a leading cause of infectious mortality. In France, he is responsible each year for several thousand deaths.

The influenza viruses (Influenza)

Influenza viruses belong to the family Orthomyxoviridae and the genus Influenzavirus, of which there are three types A, B and C. Type A and B viruses are responsible for annual influenza epidemics, but the only type A viruses are the origin of influenza pandemics. Type C virus seems to be linked to sporadic cases.

Type A viruses are the most common and most virulent; several subtypes are distinguished by their surface antigens, hemagglutinin (H1 to H16) and neuraminidase (N1 to N9). This gives therefore 144 possible combinations, but for seasonal flu, the viruses involved boils down to H1, H2, H3 and N1 or N2 responsible for the annual flu.

Duration of incubation, contagion and recovery of influenza
The incubation time of the flu (between the virus contamination and the first symptoms) varies between 24 and 48 hours. The patient is contagious for an average period of six days, including before the symptoms appear. In non-compromised individuals, recovery is complete after one to two weeks.

Vaccination against influenza
Vaccination against influenza is recommended at:

  • Pregnant women, notwithstanding of the trimester of pregnancy;
  • people, including kids from the age of 6 months, who have the following diagnosis:
    chronic bronchopulmonary diseases fitting the criteria of ALD 14 (asthma and COPD),
    Obstructive or limiting chronic respiratory insufficiencies despite of the cause, including neuromuscular diseases at risk for respiratory decompensation, upper or lower airway malformations, lung malformations or chest malformations,
    chronic respiratory diseases that do not meet the criteria of ALD but may be aggravated or decompensated by an influenza illness, including asthma, chronic bronchitis, bronchiectasis, bronchial hyperresponsiveness,
  • broncho-pulmonary dysplasias,
  • cystic fibrosis,
  • congenital heart defects cyanogenic or with PAH and heart failure,
  • severe valvulopathies,
  • severe heart failure,
  • severe arrhythmias warranting long-term treatment,
  • coronary diseases,
  • severe forms of neurological and muscular diseases (as well as myopathy)
  • history of stroke,
  • poliomyelitis, myasthenia, Charcot’s disease),
  • severe chronic nephropathy,
  • paraplegia and quadriplegia with diaphragmatic involvement,
  • severe chronic nephropathy,
  • nephrotic syndromes,
  • sickle cell disease, homozygotes and double heterozygotes S / C, thalasso-sickle cell disease,
  • type 1 and type 2 diabetes,
  • primary or acquired immunodeficiencies (oncological and hematologic diseases, hematopoietic organ and stem cell
  • transplants, hereditary immune deficiencies, inflammatory and autoimmune diseases receiving immunosuppressive
  • therapy), except persons receiving regular immunoglobulin treatment; persons infected with HIV irrespective of age and
  • immunovirological status
  • chronic liver disease with or without cirrhosis
  • obese persons with a body mass index (BMI) equal to or greater than 40 kg / m2, without associated pathology or with a pathology other than those mentioned above;
  • Persons staying in a care facility as well as in a medico-social accommodation establishment regardless of their age;
  • A famiy with infants less than six months of age with serious risk factors for severe influenza defined as follows: premature babies, especially those with broncho-dysplasia-type sequelae, and children with congenital heart disease, congenital immunodeficiency, pathology pulmonary, neurological, neuromuscular or long-lasting condition.

It requires to be renewed every year as new strains of influenza virus appear and change constantly. Influenza epidemics can occur from October to March. The best time to get vaccinated is from October to mid-December, 15 days is needed for your body to produce antibodies for your protection.

  • Treatment of flu
  • In people who are not particularly fragile, the body can effectively fight the infection with a little rest, good rehydration and antipyretic drugs. The advice is then:
    • To stay in bed
    • To drink a lot
    • Clear the nose
    • Treat fever

What is the Stomach Flu or the Viral Gastroenteritis

For more information, read our article on flu treatments .

For the children, some peculiarities are necessary. The choice of antipyretic depends on its age, your doctor will judge the usefulness of using a particular drug. To find out more, read them in our article ” Influenza, how to reduce children’s fever? “.

It is also possible to use antivirals, which can reduce the duration and intensity of symptoms. There are two classes today:

Inhibitors of viral M2 protein ( amantadine and rimantadine) are active against influenza A viruses, but have some drawbacks: they have poor renal, hepatic and neurological tolerance. Also, resistances appear quickly;

Neuraminidase inhibitors (zanamivir – Relenza ® – and oseltamivir – Tamiflu ®) would be effective in reducing the intensity and duration of symptoms if administered within 48 hours after onset of symptoms. These drugs would also have a preventive action against influenza infection. But a study * published in 2012 covering all the work concerning oseltamivir ( Tamiflu ®) reaches more disappointing conclusions concerning its effects. By including published and unpublished double-blind studies comparing this drug with placebo, the benefits would be limited to a reduction in symptom duration of 20 hours if the drug is taken within 24 hours of the first symptoms. No statistically significant reductions in serious complications (pneumonia or hospitalization) were noted by the authors. What to review its usefulness in case of an influenza pandemic?
Recall that the usefulness of antibiotics is limited to the prevention of complications of influenza (bacterial infections). They are helpless against the virus.

Health Life Media Team