Flu - Causes, symptoms and treatment. MF.

With the flu at least once in my life encountered, perhaps, everything. And this is not surprising, because the flu is one of the most common infectious diseases, which can lead to massive outbreaks and even epidemics almost every year. Therefore, it is so important to know the "enemy in person": the more dangerous it is, how to defend from it, and how it is easier to transfer.

Why is the flu so common? Why is an enormous number of adults and children suffering from this ubiquitous disease every year around the world, which can lead to very serious complications?

Influenza virus is highly variable. Annually new subspecies( strains) of the virus appear, with which our immune system has not yet met, and, therefore, can not easily cope. That is why vaccines against influenza can not provide 100% protection - there is always the possibility of a new mutation of the virus.

The history of the flu

The flu was known to mankind many centuries ago. The first documented epidemic of influenza occurred in 1580.However, at that time nothing was known about the nature of this disease.

The pandemic of respiratory infection in 1918-1920, which captured the globe, and was called "Spaniard", was probably nothing more than an epidemic of severe flu. It is known that the Spaniard was characterized by an incredible death rate - lightening resulted in pneumonia and pulmonary edema, even in young patients.

The influenza nature of the virus was established in England only in 1933 by Smith, Andrews and Leidlow, who isolated a specific virus that mainly influenced the airways from the lungs of hamsters infected with flushing from the nasopharynx of influenza patients and designated as influenza A virus. In 1940, Francis and Magilldiscovered the influenza B virus, and in 1947, Taylor identified another new version of the influenza virus - C.

Since 1940, it became possible to actively study the influenza virus and its properties - the virus began to grow in chick embryos. Since then, the study of influenza has made a big step forward - the ability to mutations has been discovered, and all areas of the virus that are capable of variability have been identified. An important discovery, of course, was the creation of a vaccine against influenza.

What is the flu

Influenza is an acute viral disease that can affect the upper and lower respiratory tract, is accompanied by severe intoxication and can lead to serious complications and deaths, mainly in elderly patients and children.

Influenza is a type of acute respiratory viral infection( ARVI), and by the way of infection, and by basic manifestations all ARVI are similar. But the flu causes much more intoxication, often it is difficult and leads to various complications.

Influenza virus

For the correct formation of views about this disease and the prediction of the situation, it is necessary to understand its structure:

• RNA-containing virus;
• The influenza virus has internal and surface antigens: internal antigens - NP( of which the capsid itself consists) and M( a layer of matrix and membrane proteins) - NP and M are type-specific antigens, so that the synthesized antibodies do not have a significant protective effect. Outside these structures, there is a lipoprotein membrane that carries external antigens-2 complex proteins( glycoprotein) - hemagglutinin( H) and neuraminidase( N)
• The antigenic structure of the influenza virus is divided into antigens into types A, B, C, and the disease can be representedone of antigenically independent viruses( it happens that at the time of epidemics and pandemics are registered at once 2 types of viruses).In general, epidemics are caused by A and B types, pandemics - A type.
• The influenza A virus is divided into 13 subtypes of H( H1-H13) and 10 subtypes by N( N1-10) - the first 3 subtypes of H and the first two subtypes of N.
are dangerous for humans. • Type A is highly variable2 variants of variability: antigenic drift and antigenic shift. Drift is a point mutation in the gene that controls the H antigen, and the shift is the complete replacement of one or both of the surface antigens, i.e. the whole RNA segment, as a result of the exchange of genetic material by human and animal influenza, and this leads to the emergence of new antigenic variants to whichthere is no immunity, which is the cause of epidemics and pandemics. Epidemics can also occur during drift, because the slightest change in the genotype of the pathogen, can "confuse memory cells" of the immune system, and it turns out that the majority of the population are unimmunized.

As of the beginning of 2016, viruses similar to the 2009 pandemic influenza A( H1N1) pdm09 virus, the A( H1N1) influenza viruses with genetic changes( according to the information of the influenza scientific research institute) that are transmitted from person to person, circulate among the population of people, so the current flupurely "pig" is not entirely correct.

Causes of the flu

The source of the infection is a sick person. Viruses stand out with saliva, sputum, nasal discharge - when coughing and sneezing. Viruses can get on the nasal mucosa, eyes or upper respiratory tract directly from the air, in close contact with the sick person;but can settle on different surfaces and then get on the mucous membranes through the hands or when using common with the sick hygiene items.

The virus then enters the mucosa of the upper respiratory tract( nose, pharynx, larynx or trachea), penetrates into cells and begins to multiply actively. In just a few hours, the virus affects almost the entire mucosa of the upper respiratory tract. The virus "loves" precisely the mucosa of the respiratory tract, and is not capable of affecting other organs. That's why it's wrong to use the term "intestinal flu" - the flu can not affect the intestinal mucosa. Most often, what is called intestinal flu - fever, intoxication accompanied by diarrhea - is a viral gastroenteritis.

It is not exactly established, due to which protective mechanisms the reproduction of the virus stops and recovery comes. Usually, after 2-5 days, the virus ceases to be released into the environment, i.e.the sick person ceases to be dangerous.

Symptoms of influenza

The incubation period for influenza is very short - from infection to the first manifestations of the disease, it takes an average of several hours to 2 days( A, C), less often up to 4 days( influenza B).

The flu always begins acutely - the patient can accurately indicate the time of onset of symptoms.

By the severity of the flow, flu, mild, moderate and severe influenza is isolated.

In all cases, to some extent, there are signs of intoxication and catarrhal phenomena. In addition, in 5-10% of cases there is also a hemorrhagic component.

Intoxication has the following manifestations:

• is primarily a high fever: with light flow, the temperature does not rise above 38 ° C;for influenza of moderate severity - 39-40 ° C;in severe cases - may increase above 40 ° C,
• chills,
• headache - especially in the forehead, eyes;severe pain in the movement of eyeballs,
• muscle pain - especially in the legs and lower back, joints,
• weakness,
• malaise,
• appetite impairment,
• may be nausea and vomiting.

Symptoms of acute intoxication usually persist for up to 5 days. If the temperature lasts longer, there are likely to be any bacterial complications.

Catarrhal phenomena persist on average 7-10 days:

• Runny nose.
• Sore throat.
• Cough: in uncomplicated course it is usually a dry cough.
• Slowness of voice.
• Cuts in the eyes, watery eyes.

Hemorrhagic phenomena:

• Small hemorrhages or vasodilation of the sclera
• Hemorrhages in the mucous: this can be seen on the mucous membranes of the mouth
• Nasal bleeding
• A very characteristic sign for the flu is redness of the face with a general pallor of the skin
• The appearance of hemorrhages on the skin is an extremely unfavorable signfrom the point of view of the forecast.

With influenza AH1N1, diarrhea is possible.

Symptoms of influenza requiring an ambulance:

• Temperature 40 ºС and above.
• Storage of heat for longer than 5 days.
• Severe headache, which does not go away when taking painkillers, especially when localizing in the occiput.
• Shortness of breath, frequent or abnormal breathing.
• Impaired consciousness - delusions or hallucinations, forgetfulness.
• Convulsions.
• Appearance of hemorrhagic rash on the skin.

With all these symptoms, as well as the appearance of other disturbing symptoms, which are not included in the picture of uncomplicated influenza, should immediately seek medical help.

Who carries heavier flu

Persons with chronic cardio-vascular diseases: especially congenital and acquired heart disease( especially mitral stenosis).
Persons suffering from chronic lung diseases( including bronchial asthma).
Patients with diabetes mellitus.
Patients with chronic kidney and blood diseases.
Pregnant.
Elderly people are over 65 years of age, because in most cases they have chronic diseases to some extent.
Children under 2 years of age and those suffering from immunodeficiency are also susceptible to developing complications of influenza. Complications of influenza

Viral complications from influenza

Primary viral pneumonia - a very serious complication of influenza. It is caused by the spread of the virus from the upper respiratory tract farther along the bronchial tree and lung damage. The disease is steadily progressing. Intoxication is expressed at the extreme, dyspnea, sometimes with the development of respiratory failure. There is a cough with scant sputum, sometimes with an admixture of blood. Viral pneumonia is predisposed to heart defects, especially mitral stenosis.

Infectious-toxic shock is an extreme degree of intoxication with a disruption in the functioning of vital organs: in particular the cardiovascular system( there is a marked increase in heart rate and a critical drop in blood pressure) and kidneys. The first manifestation of infectious-toxic shock.

Myocarditis and pericarditis - as complications of influenza were met during the pandemic "Spaniard".At present they are extremely rare.

Bacterial complications of influenza

In influenza greatly reduced resistance to natural other infections. All the reserves the body spends on fighting the virus, so bacterial infections join the clinical picture very often. Especially in the presence of any chronic bacterial diseases - all of them after the transferred flu are used to exacerbate.

• Bacterial pneumonia. Usually 2-3 days after the acute course of the disease, after the improvement, the temperature rises again. There is a cough with sputum yellow or green. It is important not to miss the onset of this complication and to start treatment on time with properly selected antibiotics.
• Otitis, sinusitis, frontalitis. Bacterial inflammation of the nasal sinuses and the ear are perhaps the most frequent complications of influenza.
• Glomerulonephritis is an inflammation of the renal tubules, which is accompanied by a decrease in kidney function.
• Meningitis, encephalitis - inflammation of the membranes and / or brain tissue. It occurs most often in patients at risk, mostly suffering from immunodeficiency.
• Septic conditions are conditions accompanied by the ingestion and subsequent reproduction of bacteria in the blood. Extremely severe conditions, often fatal.

Treatment of influenza

Non-drug treatment of influenza

Calm, better bed rest for 5 days. It is not necessary to read, watch TV, work at the computer during the acute period of the illness( as if it was not desirable).This depletes an already weakened organism, prolongs the time of illness and the risk of complications.

Plentiful warm drink at least 2 liters per day. Better rich in vitamin C - tea with lemon, rose hips, mors. Drinking a large amount of liquid daily, a sick person carries out detoxification - i.e.accelerated removal from the body of toxins, which are formed as a result of the vital activity of viruses.

Antiviral therapy

Intranasal interferon: leukocyte 5 drops in the nose 5 times a day, influenza 2 to 3 drops 3 to 4 times a day for the first 3 to 4 days.
Antifungal γ-immunoglobulin is administered to patients with immunodeficiency
Rimantadine is an antiviral agent. Treatment with rimantadine is better to start on the first day of the disease, and at least not later than 3 days. It is NOT recommended to take the drug to children under 12 years old, pregnant, people with chronic liver and kidney disease. NOT effective in swine flu. Treatment lasts 3 days.
Oseltamivir( Tamiflu). Treatment should begin on the first day of the disease. The advantage of oseltamivir is the ability to prescribe to children under 12 years of age and the effectiveness against the AH1N1 virus. The course of treatment is 3-5 days.

Nonspecific drug therapy for influenza

- Non-steroidal anti-inflammatory drugs: paracetamol, ibuprofen, diclofenac. These drugs have anti-inflammatory effect, reduce body temperature, reduce pain. It is possible to take these drugs in the composition of medicinal powders such as Coldrex, Tera - flu, etc. It should be remembered that it is not necessary to lower the temperature below 38 ° C, because it is at this body temperature that the protective mechanisms against infection are activated. Exceptions are sick, prone to convulsions, and small children.

Children are contraindicated in taking aspirin. Aspirin in viral infection can cause a serious complication - Reye syndrome - toxic encephalopathy, which manifests as epileptic seizures and coma.

- Antihistamines are medicines that are used to treat allergies. They have a powerful anti-inflammatory effect, therefore reduce all signs of inflammation: nasal congestion, mucosal edema. Preparations of the first generation of this group - dimedrol, suprastin, tavegil - have a side effect: they cause drowsiness. Preparations of the second generation - loratadine( klaritin), fenistil, semprex, zirtek - do not have this effect.

- Drops for the nose. Vasoconstrictive drops for the nose reduce edema, relieve congestion. However, this is not as safe a drug as it might seem. On the one hand, during ARVI it is necessary to use drops to reduce the edema and improve the outflow of fluid from the sinuses to prevent the development of sinusitis. However, frequent and prolonged use of vasoconstrictive drops is dangerous in the development of chronic rhinitis. Uncontrolled administration of drugs causes a significant thickening of the nasal mucosa, which leads to dependence on drops, and then to a permanent nasal congestion. Treatment of this complication is only surgical. Therefore, it is necessary to strictly adhere to the regime of drinking drops: no longer than 5-7 days, no more than 2-3 times a day.

- Rinsing of the nose. Against the common cold and for the prevention of diseases of the ENT organs, as well as complications, the nose is washed. However, most solutions for the treatment of the nose in the form of ready-made aerosols imply a procedure for nasal irrigation, rather than for immediate rinsing. Irrigation, unlike washing, can only reduce the thick consistency of nasal secretions, but will not solve the problems with their removal along with harmful bacteria. After irrigation the mucous membrane quickly dries up, which further aggravates the rhinitis, provokes swelling. Washing helps reduce inflammation, improve the mucous membrane of the nose and reduce the development of complications of the disease. Modern methods involve the washing of the nasal passages with special antiseptic agents. For example, the components of the drug "Dolphin" get to the sinuses of the nose, diluting the clots of mucus and naturally leading them out.

- Treatment of sore throat. The most effective means( it is the most unloved by many) is the gargling of the throat with disinfectant solutions. You can use infusions of sage, chamomile, as well as ready-made solutions, such as furatsilin. Rinse should be frequent - every 2 hours. In addition, disinfectant sprays can be used: hexoral, bioparox, etc.

- Cough preparations. The purpose of cough treatment is to reduce the viscosity of phlegm, make it liquid and easy to cough. It is important for this drinking regime - warm drink dilutes sputum. With difficulties with cough, you can take expectorant drugs, such as ATSTS, mukaltin, bronholitin, etc. Do not yourself( without consulting a doctor) take drugs that suppress the cough reflex - it can be dangerous.

- Antibiotics - should not be used. Antibiotics are completely powerless against viruses, they are used only by in the event of bacterial complications of .Therefore, antibiotics should not be used without prescribing a doctor, however much you like. These are unsafe for the body preparations. In addition, uncontrolled use of antibiotics leads to the emergence of resistant to them forms of bacteria.

Prevention of influenza

First and foremost, it is important not to allow viruses to enter the mucous membranes of the nose, eyes or mouth. For this, it is necessary to limit contact with people who are sick. In addition, it must be remembered that viruses can stay for some time on personal hygiene items of a sick person, as well as on various surfaces in the room where he is. Therefore, it is important to wash hands after contact with objects on which viruses can remain. Do not touch the nose, eyes, mouth with dirty hands.

It should be noted that soap certainly does not kill influenza viruses. Washing hands with soap and water causes mechanical removal of microorganisms from the hands, which is quite enough. As for various disinfectant hand lotions, there is no convincing evidence that the substances contained in them are detrimental to viruses. Therefore, the use of such lotions for the prevention of colds is completely unjustified.

In addition, the risk of contracting ARVI directly depends on immunity, i.e.the body's resistance to infections.

To maintain normal immunity it is necessary: ​​

To eat properly and fully: food should contain enough protein, fats and carbohydrates, as well as vitamins. In the autumn-spring period, when the number of fruits and vegetables in the diet decreases, an additional intake of a complex of vitamins is possible.

• Regularly exercise, preferably in the open air, including walking at a fast pace.
• It is compulsory to observe the rest regime. Adequate rest and full sleep are extremely important aspects for maintaining normal immunity.
• Avoid stress.
• Quit smoking. Smoking is a powerful factor that reduces immunity, which has a negative impact on both general resistance to infectious diseases, and on the local protective barrier - in the nasal mucosa, trachea, bronchi.

Vaccine prophylaxis for influenza

Influenza vaccines are updated annually. Vaccination is carried out by vaccines against viruses that circulated in the previous winter, so its effectiveness depends on how close the viruses are to the present. However, it is known that with repeated vaccinations, the effectiveness increases. This is due to the fact that the formation of antibodies - protective antiviral proteins - in previously vaccinated people occurs faster.

What vaccines are there?

Three types of vaccines have been developed:

Whole-virion vaccines are vaccines that represent a single influenza virus, either live or inactivated. Now these vaccines are practically not used, because they have a number of side effects and often cause the disease.
Split vaccines are split vaccines containing only a portion of the virus. They have significantly fewer side effects and are recommended for vaccination of adults.
Subunit vaccines are highly purified vaccines that practically do not cause side effects. Possible use in children.

When is it best to get vaccinated?

It is best to vaccinate in advance, before the epidemic develops - from September to December. It is also possible to be vaccinated during an epidemic, but it must be borne in mind that the immunity is formed within 7-15 days, during which it is best to carry out additional prophylaxis with antiviral agents - for example, remantadine.

Vaccine safety:

As already mentioned, for greater safety it is better to use the most purified subunit vaccines.

• Adverse reactions:
  
  Local reactions in the form of redness, pass for 1-2 days
• General reactions: fever, malaise, chills, muscle pain. They are quite rare and also occur within 1-2 days
• Allergy to vaccine components. It should be remembered that the vaccine should not be administered to people with intolerance to chicken protein, since vaccine viruses are grown using this protein, and the vaccines contain traces of it. If you are allergic to influenza vaccines, then you can not vaccinate.

Emergency flu prevention

In case of an outbreak in a closed team or during a flu epidemic, the effectiveness of the vaccination is significantly reduced, since at least 1-2 weeks are required to form a full-fledged immunity.

Therefore, if vaccination has not been carried out, especially in people at risk, a preventive antiviral drug is advisable.

• Rimantadine is taken daily at the same time in a dose of 50 mg for no more than 30 days.
• Oseltamivir( Tamiflu) in a dose of 75 mg 2 times a day for 6 weeks.
• For emergency prevention, it is also possible to use a specific anti-influenza immunoglobulin, especially in patients with immunodeficiency.