Influenza viruses are the cause of one of the most contagious diseases. According to WHO, each year in the world it contributes to millions of cases and up to 500,000. deaths. What is the flu virus? How can you get infected with it? What are the symptoms of infection? How to prevent it? What is the treatment?

Influenza virusescause respiratory infections, a major he alth problem worldwide. The flu virus causes illness in all age groups. The World He alth Organization (WHO) estimates that it may affect 5-10 percent annually. adults and 20 percent -30 percent kids. It is estimated that an estimated 3 to 5 million cases of severe complications from influenza and an estimated 250,000 to 500,000 deaths are caused by influenza every year .¹

Contents:

  1. Flu virus - what is it?
  2. Flu virus - how do you get infected?
  3. Influenza virus - what are the symptoms of infection?
  4. Influenza virus - what is the treatment?
  5. Influenza virus - how to prevent infection?
  6. Influenza virus - what is the role of vaccination?

Flu virus - what is it?

The flu virus belongs to the Orthomyxoviridae family. There are three types of virus, i.e. type A, B and C.

Influenza A virus is contagious to humans and animals (horses, pigs, mink, seals, whales and birds), and depending on the severity of the infection, it can take the form of an epidemic or even a pandemic .² In the case of the virus influenza B has been shown to be pathogenic only to humans and the course of the infection is much milder than with influenza A infection, although sometimes there may be a "full" clinical picture and complications typical of influenza A infection. Apart from humans, C infects also pigs, but despite the fairly common occurrence of infections with this type of virus, the infection against it is asymptomatic .²

Influenza A is responsible for the majority of seasonal, epidemic and pandemic infections.

The flu virus is the cause of seasonal flu, i.e. flu that occurs every year during the epidemic period (in the northern hemisphere, including Poland, from late autumn to early spring). Seasonal flu is caused by common flu viruses found in humans. The flu virus is also the culprit of the flupandemic, i.e. influenza occurring every several or several dozen years in the form of epidemics spreading throughout the world. This type of flu is caused by new types of influenza virus that have been unknown in humans, e.g. swine flu in the 2009/2010 season caused by a new variant of the A / H1N1 virus or H5N1 and H5N8 avian flu.

Flu virus - how do you get infected?

The flu virus most often attacks during the fall, early winter or spring solstice. Influenza infection occurs:

Influenza virus, after entering the body, infects and damages epithelial cells of the respiratory system (nose, larynx, trachea and bronchi).

  • by droplets - in the case when a sick person coughs or sneezes, saliva droplets containing viruses can settle on the mucosa of the mouth and nose of a person who is close to the sick person. Infection can also occur through direct contact, e.g. a kiss, shaking hands
  • by ingestion through contact with infected objects - some viruses can survive in the environment for several hours, e.g. on everyday objects
  • as a result of close contact (e.g. touching) with sick or dead animals - pigs, domestic or wild birds, e.g. avian flu. You can also get this disease by eating raw or undercooked meat or raw eggs from sick birds

The hatching period for the influenza virus is 18 to 72 hours, usually 2 days. An infected person spreads the virus for the entire duration of the disease.

Flu virus - symptoms of infection

Symptoms of influenza virus infection are:

  • high, up to 40 degrees C., fever
  • chills
  • headache
  • muscle and joint pain
  • general weakness
  • dry cough
  • qatar
  • in some cases vomiting and diarrhea - more often in children and adolescents

Symptoms resolve spontaneously after 5 - 7 days, but coughing, fatigue and a feeling of breakdown may persist for around 2 weeks

Influenza virus AH3N2 [TOWIDEO]

Flu virus - treatment

Treatment of infection with influenza virus is symptomatic. It is recommended to stay at home and rest, drink plenty of fluids, use painkillers and antipyretics (containing active substances such as paracetamol or ibuprofen). In some cases, your doctor may recommend flu antiviral medications.

Influenza virus - preventing infection with influenza virus

Vaccination is the most effective method of preventing infection with the flu virus. There are also othersmethods that will reduce the risk of disease. The most important thing is personal hygiene - washing your hands, covering your mouth with a tissue while sneezing. A he althy diet will also help.

Flu virus - why do you have to get vaccinated against flu every year?

Being sick does not provide immunity to infection. Flu vaccinations must be repeated every season. This is because the flu virus is highly variable. If the flu virus attacks an organism that has already been infected with another strain, it can mix up the genes and create a completely new virus. This process is called genetic reassortment.

It is best to get vaccinated in September, because vaccines are already available then. First of all, young children, the elderly, pregnant women and people after transplantation should be vaccinated.

In the prevention of influenza in people with a high risk of complications, it is possible to use anti-viral drugs active against the influenza virus. The drug is not a substitute for flu vaccination.

Source:

1. gis.gov.pl, https://gis.gov.pl/images/ep/choroby_zaka%C5%BAne/informacja_dotycz%C4%85ca_sezonu_grypowego_2016_2017.pdf

2. Wierzbicka-Woś A., Tokarz-Deptuła B., Deptuła W., The immune system and the influenza virus, "Advances in Hygiene and Experimental Medicine" 2015;69

Category:

Infectious diseases