Severe flu. Forms and symptoms of influenza

- an acute viral respiratory infection caused by RNA-containing influenza viruses A, B and C, manifested by fever, intoxication and damage to the epithelial lining of the upper respiratory tract. Influenza belongs to the group of acute respiratory viral infections - ARVI. A person with influenza presents the greatest infectious danger in the first 5-6 days from the onset of the disease. The route of transmission of influenza is aerosol. The duration of the disease, as a rule, does not exceed a week. However, with the flu, complications such as otitis media, sinusitis, pneumonia, cystitis, myositis, pericarditis, and hemorrhagic syndrome can occur. The flu is especially dangerous for pregnant women, as it can lead to the threat of termination of pregnancy.

General information

- an acute viral respiratory infection caused by RNA-containing influenza viruses A, B and C, manifested by fever, intoxication and damage to the epithelial lining of the upper respiratory tract. Influenza belongs to the group of acute respiratory viral infections - ARVI.

Exciter characteristic

Influenza virus belongs to the genus Influenzavirus, type A virus can infect humans and some animals, types B and C multiply only in humans. Influenza viruses are characterized by high antigenic variability (highly developed in type A and B viruses, less in C). Antigenic polymorphism contributes to frequent epidemics, multiple morbidity during the season, and also does not allow developing a sufficiently reliable group-specific prophylaxis. The influenza virus is unstable, easily dies when the temperature rises to 50-60 degrees, under the influence of chemical disinfectants. At 4 °C it can remain viable for up to 2-3 weeks.

The reservoir and source of infection is a sick person (with obvious clinical manifestations or an erased form of infection). The maximum isolation of the virus occurs in the first 5-6 days of the disease, the contagiousness depends on the severity of catarrhal symptoms and the concentration of the virus in the secretion of the mucous membrane of the respiratory tract. Influenza A virus is also isolated by sick pigs, horses and birds. One of the modern theories suggests that migratory birds play a certain role in the spread of the influenza virus on a global scale, mammals serve as a reservoir of infection and contribute to the formation of new strains that can subsequently infect humans.

The mechanism of transmission of influenza is aerosol, the virus spreads by airborne droplets. Excretion occurs with saliva and sputum (when coughing, sneezing, talking), which in the form of a fine aerosol spreads in the air and is inhaled by other people. In some cases, it is possible to implement a household contact route of transmission (mainly through dishes, toys).

Human natural susceptibility to the influenza virus is high, especially for new serotypes. Immunity is type-specific, its duration reaches 1-3 years in type A influenza, 3-4 years in type B. Breastfed babies receive antibodies from the mother, but often this immunity does not protect against infection. The prevalence of the influenza virus is ubiquitous, epidemics regularly break out, often on a global scale.

flu symptoms

The incubation period of influenza usually ranges from several hours to three days, the onset is predominantly acute, the course can be mild, moderate, severe, with or without complications. The clinical picture of influenza is represented by three main symptom complexes: intoxication, catarrh and hemorrhage.

The development of intoxication syndrome begins from the first hours of the disease, body temperature can rise up to 40 degrees, chills, headaches and dizziness, general weakness are noted. There may be moderate myalgia and arthralgia, convulsions, impaired consciousness. The intensity of the intoxication syndrome determines the severity of the course of uncomplicated influenza and can vary widely, from moderate malaise to an intense febrile reaction, central vomiting, convulsions, confusion and delirium.

The fever often proceeds in two waves, the symptoms usually begin to subside by the 5th-7th day of illness. When viewed during a febrile period, hyperemia of the face, hyperthermia and dry skin are noted, tachycardia is detected, and some decrease in blood pressure is possible. Catarrhal symptoms appear soon after the development of intoxication (sometimes it is weakly expressed or may be completely absent). Patients complain of dry cough, discomfort and soreness in the throat and nasopharynx, runny nose. A clinic of laryngitis and bronchitis may appear: hoarseness of voice, rawness behind the sternum with a dry, growing in intensity, strained cough. On examination, slight hyperemia of the pharynx and posterior pharyngeal wall, tachypnea are sometimes noted.

In 5-10% of cases, influenza can contribute to the development of a hemorrhagic symptom. At the same time, small hemorrhages in the mucous membrane of the oropharynx, bleeding from the nose join the catarrhal phenomena. With the development of severe hemorrhage, it may progress to acute pulmonary edema. Influenza is usually not accompanied by symptoms from the organs of the abdominal cavity and small pelvis, if such a clinic takes place, then it is predominantly neurogenic in nature.

Influenza can contribute to the development of otitis, as well as be complicated by sinusitis, sinusitis, frontal sinusitis. On the part of other organs and systems, nephritis, pyelocystitis, myositis, inflammation of the heart sac (pericarditis) can be noted. Complications of the heart with influenza is considered to be the cause of the increase in the frequency of myocardial infarction during the epidemic, the development of acute cardiovascular insufficiency. In pregnant women, influenza can cause spontaneous abortion or fetal death.

Influenza Diagnosis

Preliminary diagnosis is carried out on the basis of the clinical picture and express diagnostic data of RNIF or ELISA (detection of the influenza virus antigen in swabs taken in the nasal cavity), the diagnosis is confirmed by serological diagnostic methods: an increase in antibody titer is determined using RTGA, RSK, RNHA, ELISA. More than a fourfold increase has diagnostic value.

If pneumonia is suspected, a patient with influenza may need to consult a pulmonologist and take an x-ray of the lungs. With the development of complications from the ENT organs, an examination by an otolaryngologist with oto- and rhinoscopy is necessary.

Flu treatment

Influenza is treated mainly on an outpatient basis, hospitalizing only patients with severe and complicated forms of infection. In addition, children from orphanages and boarding schools are subject to hospitalization.

For the period of fever, patients are recommended bed rest, plenty of fluids, a balanced, complete diet, and vitamins. As a means of etiotropic therapy in the first days of the disease, rimantadine is prescribed (has contraindications: age up to 14 years, pregnancy and lactation, pathologies of the kidneys and liver), oseltamivir. Late appointment of antiviral agents is ineffective. Interferons may be recommended. In addition to antiviral therapy, vitamin C, calcium gluconate, rutin, antipyretic, antihistamines are prescribed.

The severe course of influenza often requires detoxification measures (parenteral infusion of Hemodez solutions, rheopolyglucin) with forcing diuresis. Eufillin, ascorbic acid, diphenhydramine are often added to detoxification solutions. With developing pulmonary or cerebral edema, the dosage of saluretics is increased, intravenous prednisone is prescribed, and the necessary intensive care measures are taken. Developing cardiovascular insufficiency is an indication for the appointment of thiamine pyrophosphate, sulfocamphoric acid with procaine, potassium and magnesium preparations. At the same time, the necessary correction of the internal acid-base homeostasis is carried out, the airway patency is controlled.

Forecast and prevention of influenza

Mostly the prognosis of influenza infection is favorable, recovery occurs in 5-6 days. The deterioration of the prognosis causes a severe course in young children, the elderly, the development of life-threatening complications. The prognosis of the course of pregnancy is unfavorable - the flu quite often provokes its termination.

Currently, measures have been developed for the specific prevention of influenza, which is carried out in relation to the most common strains. The multiantigenic structure of influenza epidemics does not allow vaccination to completely eliminate the possibility of influenza, but the sensitized organism tolerates the infection much easier, the risk of developing severe complications in immunized children is significantly reduced. It is advisable to get vaccinated against influenza a few weeks before the predicted epidemic period. Anti-influenza immunity is short-term, it is desirable to immunize every year.

General prevention during periods of mass epidemics includes the usual measures to prevent the spread of infections transmitted by airborne droplets. Personal prevention consists in avoiding contact with patients, crowded places, wearing a gauze mask that covers the respiratory tract, taking prophylactic antiviral drugs in case of a risk of infection, and also measures aimed at strengthening the immune properties of the body.

Influenza is a severe acute infectious disease, which is characterized by severe toxicosis, catarrhal symptoms and bronchial lesions. Influenza, the symptoms of which occur in people regardless of their age and gender, annually manifests itself in the form of an epidemic, more often in the cold season, while approximately 15% of the world's population is affected.

History of influenza

The flu has long been known to mankind. Its first epidemic was in 1580. In those days, people knew nothing about the nature of this disease. Respiratory disease pandemic in 1918-1920. was called the "Spanish flu", but it was precisely an epidemic of severe influenza. At the same time, incredible mortality was noted - at lightning speed, even young people developed pneumonia and pulmonary edema.

The viral nature of influenza was only established in 1933 in England by Andrews, Smith, and Laidlaw, who isolated a specific virus that affected the respiratory tract of hamsters that were infected by swabs from the nasopharynx of patients with influenza. The causative agent was named the influenza A virus. Then in 1940, Magil and Francis isolated the type B virus, in 1947 Taylor discovered another variant - the type C influenza virus.

The influenza virus is one of the RNA-containing orthomyxoviruses, its particle size is 80-120 nm. It is weakly resistant to chemical and physical factors, it is destroyed in a few hours at room temperature, and at low temperatures (from -25°C to -70°C) it can be preserved for several years. It is killed by drying, heating, exposure to small amounts of ultraviolet radiation, chlorine, ozone.

How infection occurs

The source of influenza infection is an exceptionally sick person with erased or obvious forms of the disease. The route of transmission is airborne. The patient is most contagious in the first days of the disease, when the virus with droplets of mucus during sneezing and coughing begins to be released into the external environment. With an uncomplicated course of the disease, the isolation of the virus stops approximately 5-6 days from its onset. In the case of pneumonia, which can complicate the course of influenza, the virus in the body can be detected within two to three weeks from the onset of the disease.

The incidence is on the rise, and influenza outbreaks occur during the cold season. Every 2-3 years, an epidemic is possible, which is caused by the type A influenza virus, it has an explosive character (20-50% of the population can get sick in 1-1.5 months). An influenza type B epidemic is characterized by a slower spread, it lasts approximately 2-3 months and affects up to 25% of the population.

There are such forms of the course of the disease:

• Light - body temperature rises by no more than 38 ° C, symptoms of intoxication are mild or absent.
• Medium - body temperature in the range of 38.5-39.5 ° C, the classic symptoms of the disease are noted: intoxication (headache, photophobia, muscle and joint pain, profuse sweating), typical changes in the posterior pharyngeal wall, redness of the conjunctiva, nasal congestion, tracheal damage and larynx (dry cough, chest pain, hoarse voice).
• Severe form - pronounced intoxication, body temperature 39-40°C, nosebleeds, signs of encephalopathy (hallucinations, convulsions), vomiting.
• Hypertoxic - body temperature above 40°C, symptoms of intoxication are most pronounced, resulting in toxicosis of the nervous system, cerebral edema and infectious-toxic shock of varying severity. Respiratory failure may develop.
• lightning form influenza is dangerous with the possibility of death, especially for weakened patients, as well as patients with comorbidities they have. With this form, swelling of the brain and lungs, bleeding and other serious complications develop.

flu symptoms

The duration of the incubation is approximately 1-2 days (possibly from several hours to 5 days). This is followed by a period of acute clinical manifestations of the disease. The severity of uncomplicated disease is determined by the duration and severity of intoxication.

The intoxication syndrome in influenza is the leading one, it is expressed already from the first hours after the onset of the manifestation of the disease. In all cases, influenza has an acute onset. Its first sign is an increase in body temperature - from insignificant or subfebrile to reaching maximum levels. In a few hours the temperature becomes very high, it is accompanied by chills.

With a mild form of the disease, the temperature in most cases is subfebrile. With influenza, the temperature reaction is characterized by relative short duration and severity. The duration of the febrile period is approximately 2-6 days, sometimes longer, and then the temperature begins to decrease rapidly. In the presence of elevated temperature for a long time, it is possible to assume the development of complications.

The leading sign of intoxication and one of the first symptoms of the flu is a headache. Its localization is the frontal region, especially in the supraorbital region, near the superciliary arches, sometimes behind the orbits of the eyes, it can increase with the movements of the eyeballs. Headache in the elderly is more often characterized by prevalence. The severity of the headache is very different. In severe cases of influenza, headache can be combined with repeated vomiting, sleep disturbance, hallucinations, and symptoms of damage to the nervous system. Children may have seizures.

The most common flu symptoms are fatigue, feeling unwell, general weakness, and increased sweating. Increased sensitivity to sharp sounds, bright light, cold. The patient is most often conscious, but may be delirious.

A common symptom of the disease is joint and muscle pain, as well as aches throughout the body. The appearance of the patient is characteristic: a puffy, reddened face. It often happens, accompanied by lacrimation and photophobia. As a result of hypoxia and impaired capillary circulation, the patient's face may acquire a bluish tint.

Catarrhal syndrome with influenza infection is most often mild or absent. Its duration is 7-10 days. The cough lasts the longest.

Already at the beginning of the disease, changes in the oropharynx can be seen: a significant reddening of the soft palate. After 3-4 days from the onset of the disease, an infection of the vessels develops at the site of redness. In severe influenza, small hemorrhages form in the soft palate, in addition, its swelling and cyanosis can be detected. The back wall of the pharynx is reddened, shiny, often grainy. Patients are concerned about dryness and sore throat. 7-8 days after the onset of the disease, the mucous membrane of the soft palate acquires a normal appearance.

Changes in the nasopharynx are manifested by swelling, redness and dryness of the mucosa. Breathing through the nose due to swelling of the nasal concha is difficult. After 2-3 days, the above symptoms are replaced by nasal congestion, less often - discharge from the nose, they occur in about 80% of patients. As a result of toxic damage to the vascular walls, as well as intense sneezing in this disease, nosebleeds are often possible.

In the lungs with influenza, most often hard breathing, dry wheezing of a short duration is possible. Typical of influenza is tracheobronchitis. It is manifested by pain or soreness behind the sternum, dry painful cough. (hoarseness, sore throat) can be combined with.

In children with influenza laryngotracheitis, croup is possible - a condition in which a viral disease is accompanied by the development of edema of the larynx and trachea, which is complemented by shortness of breath, rapid breathing (i.e. shortness of breath), "barking" cough. Cough occurs in about 90% of patients and in uncomplicated influenza it lasts about 5-6 days. Breathing may become more frequent, but its character does not change.

Cardiovascular changes in influenza occur as a result of toxic damage to the heart muscle. On auscultation of the heart, muffled tones can be heard, sometimes a rhythm disturbance or a systolic murmur at the apex of the heart. At the beginning of the disease, the pulse is frequent (as a result of an increase in body temperature), while the skin is pale. After 2-3 days from the onset of the disease, along with weakness in the body and lethargy, the pulse becomes rare, and the patient's skin turns red.

Changes in the digestive organs are not significantly expressed. Appetite may decrease, intestinal peristalsis worsens, constipation joins. There is a thick white coating on the tongue. The abdomen is not painful.

Due to damage to the kidney tissue by viruses, changes occur in the organs of the urinary system. In the analysis of urine, protein and red blood cells may appear, but this happens only with a complicated course of influenza.

Toxic reactions from the nervous system most often manifest themselves in the form of a sharp headache, which is aggravated by various external irritating factors. Drowsiness or, on the contrary, excessive excitement is possible. Often there are delusional states, loss of consciousness, convulsions, vomiting. Meningeal symptoms can be detected in 3% of patients.

In the peripheral blood, the amount also increases.

If the flu has an uncomplicated course, the fever may last 2-4 days, and the disease ends in 5-10 days. After the disease, post-infectious asthenia is possible for 2-3 weeks, which is manifested by general weakness, sleep disturbance, increased fatigue, irritability, headache and other symptoms.

Flu treatment

In the acute period of the disease, bed rest is necessary. Mild to moderate influenza can be treated at home, but severe forms require hospitalization. Plentiful drink is recommended (compotes, fruit drinks, juices, weak tea).

An important link in the treatment of influenza is the use of antiviral agents - arbidol, anaferon, rimantadine, groprinosin, viferon and others. They can be purchased at a pharmacy without a doctor's prescription.

To combat fever, antipyretic drugs are indicated, of which there are a lot today, but it is preferable to take paracetamol or ibuprofen, as well as any drugs that are made on their basis. Antipyretic drugs are indicated if the body temperature exceeds 38 ° C.

To combat the common cold, various drops are used - vasoconstrictor (nazol, farmazolin, rinazolin, vibrocil, etc.) or saline (no-salt, quicks, salin).

Remember that flu symptoms are not as harmless as they seem at first glance. Therefore, with this disease, it is important not to self-medicate, but to consult a doctor and follow all his appointments. Then, with a high probability, the disease will pass without complications.

If you have symptoms that indicate the flu, you should contact your treating pediatrician (therapist).

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The site provides reference information for informational purposes only. Diagnosis and treatment of diseases should be carried out under the supervision of a specialist. All drugs have contraindications. Expert advice is required!

What is flu?

As a separate disease, influenza was first described in 1403. Since then, about 18 pandemics have been reported ( epidemics in which the disease affects a large part of the country or even several countries) influenza. Since the cause of the disease was unclear, and there was no effective treatment, most people who fell ill with influenza died from developing complications ( the death toll was in the tens of millions). So, for example, during the Spanish flu ( 1918 - 1919) infected more than 500 million people, of which about 100 million died.

In the middle of the 20th century, the viral nature of influenza was established and new methods of treatment were developed, which made it possible to significantly reduce mortality ( mortality) for this pathology.

flu virus

In addition to RNA, the influenza virus has a number of other components in its structure, which allows it to be divided into subspecies.

In the structure of the influenza virus, there are:

• Hemagglutinin ( hemagglutinin, H) a substance that binds red blood cells red blood cells responsible for transporting oxygen in the body).
• Neuraminidase ( neuraminidase, N) - a substance responsible for damage to the mucous membrane of the upper respiratory tract.

Despite their danger, all influenza viruses have a rather low resistance and are rapidly destroyed in the external environment.

Influenza virus dies:

• As part of human secretions ( phlegm, mucus) at room temperature- in 24 hours.
• At minus 4 degrees– within a few weeks.
• At minus 20 degrees within a few months or even years.
• At a temperature of plus 50 - 60 degrees– within a few minutes.
• In 70% alcohol– within 5 minutes.
• When exposed to ultraviolet rays ( direct sunlight) - almost instantly.

Influenza (influenza) epidemiology)

The peak incidence occurs during the cold seasons ( autumn-winter and winter-spring periods). The virus spreads rapidly in communities, often causing epidemics. From an epidemiological point of view, the most dangerous is the period of time during which the air temperature ranges from minus 5 to plus 5 degrees, and the air humidity decreases. It is in such conditions that the likelihood of contracting the flu is as high as possible. On summer days, the flu is much less common, without affecting a large number of people.

How does the flu get transmitted?

Influenza virus transmission occurs:

• Airborne. The main way the virus spreads, causing the development of epidemics. The virus is released into the external environment from the respiratory tract of a sick person during breathing, talking, coughing or sneezing ( virus particles are found in droplets of saliva, mucus or sputum). In this case, all people who are in the same room with an infected patient are at risk of infection ( in the classroom, in public transport and so on). entrance gate ( by entering the body) in this case, there may be mucous membranes of the upper respiratory tract or eyes.
• Contact household way. The possibility of transmitting the virus by contact-household is not excluded ( when mucus or sputum containing the virus comes into contact with the surfaces of toothbrushes, cutlery and other objects that are subsequently used by other people), but the epidemiological significance of this mechanism is low.

Incubation period and pathogenesis ( development mechanism) influenza

In the development of influenza, 5 phases are conditionally distinguished, each of which is characterized by a certain stage in the development of the virus and characteristic clinical manifestations.

In the development of influenza, there are:

• reproduction phase ( breeding) virus in cells. After infection, the virus enters the epithelial cells ( upper mucosal layer), starting to actively multiply inside them. As the pathological process develops, the affected cells die, and the new viral particles released at the same time penetrate into neighboring cells and the process repeats. This phase lasts several days, during which the patient begins to show clinical signs of damage to the mucous membrane of the upper respiratory tract.
• Phase of viremia and toxic reactions. Viremia is characterized by the entry of viral particles into the bloodstream. This phase begins in the incubation period and can last up to 2 weeks. The toxic effect in this case is due to hemagglutinin, which affects erythrocytes and leads to impaired microcirculation in many tissues. At the same time, a large amount of decay products of cells destroyed by the virus is released into the bloodstream, which also has a toxic effect on the body. This is manifested by damage to the cardiovascular, nervous and other systems.
• phase of the respiratory tract. A few days after the onset of the disease, the pathological process in the respiratory tract is localized, that is, the symptoms of a predominant lesion of one of their departments come to the fore ( larynx, trachea, bronchi).
• Phase of bacterial complications. Reproduction of the virus leads to the destruction of respiratory epithelial cells, which normally perform an important protective function. As a result of this, the airways become completely defenseless in the face of many bacteria that enter with the inhaled air or from the patient's oral cavity. Bacteria easily settle on the damaged mucous membrane and begin to develop on it, intensifying inflammation and contributing to even more pronounced damage to the respiratory tract.
• The phase of the reverse development of the pathological process. This phase begins after the complete removal of the virus from the body and is characterized by the restoration of affected tissues. It should be noted that in an adult, the complete recovery of the epithelium of the mucous membrane after the flu occurs no earlier than after 1 month. In children, this process proceeds faster, which is associated with more intense cell division in the child's body.

Types and forms of influenza

Flu type A

• Seasonal flu. The development of this form of influenza is due to various subspecies of the influenza A virus, which constantly circulate among the population and are activated during the cold seasons, which causes the development of epidemics. In people who have been ill, immunity against seasonal influenza persists for several years, however, due to the high variability of the antigenic structure of the virus, people can get seasonal influenza every year, becoming infected with various viral strains ( subspecies).
• Swine flu. Swine flu is commonly referred to as a disease that affects humans and animals and is caused by subspecies of the A virus, as well as some strains of the C virus. An outbreak of "swine flu" registered in 2009 was caused by the A / H1N1 virus. It is assumed that the emergence of this strain occurred as a result of infection of pigs with common ( seasonal) influenza virus from humans, after which the virus mutated and led to the development of an epidemic. It should be noted that the A/H1N1 virus can be transmitted to humans not only from sick animals ( when working in close contact with them or when eating poorly processed meat), but also from sick people.
• Bird flu. Avian influenza is a viral disease that mainly affects poultry and is caused by varieties of the influenza A virus, which is similar to the human influenza virus. In birds infected with this virus, many internal organs are affected, which leads to their death. Human infection with the avian influenza virus was first reported in 1997. Since then, there have been several more outbreaks of this form of the disease, in which 30 to 50% of infected people died. Human-to-human transmission of the avian influenza virus is currently considered impossible ( you can only get infected from sick birds). However, scientists believe that as a result of the high variability of the virus, as well as the interaction of avian and seasonal human influenza viruses, a new strain may form, which will be transmitted from person to person and may cause another pandemic.

Influenza type B and C

Type B virus is also able to change its antigenic composition when exposed to various environmental factors. However, it is more “stable” than the type A virus, therefore it rarely causes epidemics, and no more than 25% of the country's population falls ill. Type C virus causes only sporadic ( single) cases of disease.

Flu symptoms and signs

• general weakness;
• aching muscles;
• an increase in body temperature;
• nasal congestion;
• nasal discharge;
• nosebleeds;
• sneezing
• cough;
• eye damage.

General weakness with flu

Headache and dizziness with the flu

Headache can be localized in the frontal, temporal or occipital region, in the region of the superciliary arches or eyes. As the disease progresses, its intensity gradually increases from mild or moderate to extremely pronounced ( often intolerable). Pain is aggravated by any movements or turns of the head, loud sounds or bright lights.

Also, from the first days of the disease, the patient may experience periodic dizziness, especially when moving from a lying position to a standing position. The mechanism of development of this symptom is a violation of blood microcirculation at the level of the brain, as a result of which, at a certain point, its nerve cells may begin to experience oxygen starvation ( due to lack of oxygen in the blood). This will lead to a temporary disruption of their functions, one of the manifestations of which may be dizziness, often accompanied by blackouts in the eyes or tinnitus. Unless there are any serious complications ( for example, when dizzy, a person can fall and hit his head, causing a brain injury), after a few seconds, the blood supply to the brain tissue normalizes and dizziness disappears.

Aches and pains in the muscles with the flu

Under normal conditions, muscles constantly need energy ( as glucose, oxygen and other nutrients) that they get from their blood. At the same time, by-products of their vital activity are constantly formed in muscle cells, which are normally released into the blood. If microcirculation is disturbed, both of these processes are disturbed, as a result of which the patient feels muscle weakness ( due to lack of energy), as well as a feeling of pain or aches in the muscles, which is associated with a lack of oxygen and the accumulation of metabolic by-products in the tissues.

An increase in body temperature with the flu

Sources of pyrogens in influenza are cells of the immune system ( leukocytes). When a foreign virus enters the body, they rush to it and begin to actively fight it, while releasing many toxic substances into the surrounding tissues ( interferon, interleukins, cytokines). These substances fight a foreign agent, and also affect the thermoregulation center, which is the direct cause of the temperature increase.

The temperature reaction in influenza develops acutely, due to the rapid entry of a large number of viral particles into the bloodstream and the activation of the immune system. The temperature reaches its maximum figures by the end of the first day after the onset of the disease, and starting from 2-3 days it can decrease, which indicates a decrease in the concentration of viral particles and other toxic substances in the blood. Quite often, a decrease in temperature can occur in waves, that is, 2 to 3 days after the onset of the disease ( usually in the morning), it decreases, but in the evening it rises again, normalizing in another 1-2 days.

A repeated increase in body temperature 6–7 days after the onset of the disease is an unfavorable prognostic sign, usually indicating the addition of a bacterial infection.

Chills with influenza

The mechanism of development of chills in influenza is associated with a violation of the work of the thermoregulation center. Under the influence of pyrogens, the point of "optimal" body temperature shifts upward. As a result, the nerve cells responsible for thermoregulation “decide” that the body is too cold and trigger the mechanisms described above to increase the temperature.

Decreased appetite with influenza

At the same time, it is worth noting that a decrease in appetite does not reduce the body's need for proteins, fats, carbohydrates, vitamins and useful trace elements. In contrast, with the flu, the body needs more nutrients and energy sources to adequately fight off the infection. That is why throughout the entire period of illness and recovery, the patient must eat regularly and fully.

Nausea and vomiting with the flu

Nausea may persist for some time ( minutes or hours), however, with a further increase in the concentration of toxins in the blood, vomiting occurs. During the gag reflex, the muscles of the stomach, anterior abdominal wall, and diaphragm contract ( respiratory muscle located on the border between the thoracic and abdominal cavities), as a result of which the contents of the stomach are pushed into the esophagus, and then into the oral cavity.

Vomiting with influenza can occur 1-2 times during the entire acute period of the disease. It is worth noting that due to a decrease in appetite, the patient's stomach is often empty at the time of the onset of vomiting ( it may contain only a few milliliters of gastric juice). With an empty stomach, vomiting is more difficult to tolerate, since muscle contractions during the gag reflex are longer and more painful for the patient. That's why, with a premonition of vomiting ( i.e. severe nausea), and after it it is recommended to drink 1 - 2 glasses of warm boiled water.

It is also important to note that vomiting with influenza can occur without previous nausea, against the background of a pronounced cough. The mechanism of development of the gag reflex in this case is that during an intense cough, there is a pronounced contraction of the muscles of the abdominal wall and an increase in pressure in the abdominal cavity and in the stomach itself, as a result of which food can be “pushed out” into the esophagus and vomiting develops. Also, vomiting can be provoked by clots of mucus or sputum that fall on the mucous membrane of the pharynx during coughing, which also leads to the activation of the vomiting center.

Nasal congestion with influenza

Nasal congestion can occur if the virus enters the human body through the nasal passages along with inhaled air. In this case, the virus invades the epithelial cells of the nasal mucosa and actively multiplies in them, causing their death. Activation of local and systemic immune responses is manifested by migration of cells of the immune system to the site of introduction of the virus ( leukocytes), which, in the process of fighting the virus, release many biologically active substances into the surrounding tissues. This, in turn, leads to the expansion of the blood vessels of the nasal mucosa and their overflow with blood, as well as to an increase in the permeability of the vascular wall and the release of the liquid part of the blood into the surrounding tissues. As a result of the described phenomena, swelling and swelling of the nasal mucosa occurs, which covers most of the nasal passages, making it difficult for air to move through them during inhalation and exhalation.

Nasal discharge with influenza

Bleeding from the nose with the flu

Sneezing with the flu

The air flow formed during sneezing moves at a speed of several tens of meters per second, capturing dust microparticles, torn cells and virus particles on the surface of the mucous membrane on its way and removing them from the nose. The negative point in this case is the fact that the air exhaled during sneezing contributes to the spread of microparticles containing the influenza virus at a distance of up to 2-5 meters from the sneezer, as a result of which all people in the affected area can become infected with the virus.

Sore throat with flu

In the first days of the disease, patients may complain of a feeling of soreness or soreness in the throat. This is due to the necrosis of epithelial cells, which are rejected and irritate sensitive nerve endings. In the future, the protective properties of the mucous membrane are reduced, as a result of which patients begin to experience pain during a conversation, when swallowing hard, cold or hot food, with a sharp and deep breath or exhalation.

Cough with flu

In the first days after the onset of flu symptoms, a dry cough ( without sputum) and painful, accompanied by severe pains of a stabbing or burning nature in the chest and throat. The mechanism of development of cough in this case is due to the destruction of the mucous membrane of the upper respiratory tract. Desquamated epithelial cells irritate specific cough receptors, which triggers the cough reflex. After 3-4 days, the cough becomes wet, that is, it is accompanied by sputum of a mucous nature ( colorless, odorless). Purulent sputum that appears 5-7 days after the onset of the disease ( greenish color with an unpleasant odor) indicates the development of bacterial complications.

It is worth noting that when coughing, as well as sneezing, a large number of viral particles are released into the environment, which can cause infection of the people around the patient.

Influenza eye injury

Symptoms of conjunctivitis ( inflammation of the conjunctiva) are usually short-lived and subside along with the removal of the virus from the body, however, with the addition of a bacterial infection, purulent complications may develop.

Flu symptoms in newborns and children

The course of influenza in children is characterized by:

• Tendency to damage the lungs. The defeat of the lung tissue by the influenza virus in adults is extremely rare. At the same time, in children, due to certain anatomical features ( short trachea, short bronchi) the virus spreads quite quickly through the respiratory tract and infects the pulmonary alveoli, through which oxygen is normally transported into the blood and carbon dioxide is removed from the blood. The destruction of the alveoli can cause the development of respiratory failure and pulmonary edema, which without urgent medical attention can lead to the death of the baby.
• Tendency to nausea and vomiting. In children and adolescents ( aged 10 to 16 years) nausea and vomiting in influenza are most common. It is assumed that this is due to the imperfection of the regulatory mechanisms of the central nervous system, in particular, the increased sensitivity of the vomiting center to various stimuli ( to intoxication, to pain syndrome, to irritation of the mucous membrane of the pharynx).
• Tendency to develop seizures. Newborns and infants are most at risk for seizures ( involuntary, pronounced and extremely painful muscle contractions) for influenza. The mechanism of their development is associated with an increase in body temperature, as well as a violation of microcirculation and the delivery of oxygen and energy to the brain, which ultimately leads to impaired function of nerve cells. Due to certain physiological characteristics in children, these phenomena develop much faster and are more severe than in adults.
• Mild local manifestations. The immune system of the child has not yet been formed, which is why it is not able to adequately respond to the introduction of foreign agents. As a result, among the symptoms of influenza, pronounced manifestations of intoxication of the body come to the fore, while local symptoms can be erased and mild ( there may be a slight cough, nasal congestion, the periodic appearance of mucous secretions from the nasal passages).

Influenza Severity

Depending on the severity, there are:

• Mild flu. With this form of the disease, the symptoms of general intoxication are slightly expressed. Body temperature rarely reaches 38 degrees and usually returns to normal after 2 to 3 days. There is no threat to the patient's life.
• Influenza of moderate severity. The most common variant of the disease, in which there are pronounced symptoms of general intoxication, as well as signs of damage to the upper respiratory tract. Body temperature can rise to 38 - 40 degrees and remain at this level for 2 - 4 days. With the timely start of treatment and the absence of complications, there is no threat to the life of the patient.
• A severe form of the flu. It is characterized by fast during few hours) the development of intoxication syndrome, accompanied by an increase in body temperature to 39 - 40 degrees or more. Patients are lethargic, drowsy, often complain of severe headaches and dizziness, may lose consciousness. Fever may persist for up to a week, and complications from the lungs, heart, and other organs that develop can pose a threat to the patient's life.
• Hypertoxic ( lightning fast) shape. It is characterized by an acute onset of the disease and rapid damage to the central nervous system, heart and lungs, which in most cases leads to the death of the patient within 24-48 hours.

gastric ( intestinal) flu

The source of infection may be a sick person or a latent carrier ( a person who has a pathogenic virus in his body, but there are no clinical manifestations of the infection). The main mechanism for the spread of infection is fecal-oral, that is, the virus is excreted from the patient's body along with feces, and if personal hygiene rules are not followed, it can get on various food products. If a healthy person eats these products without special heat treatment, he runs the risk of contracting the virus. Less common is the airborne route of spread, in which a sick person releases microparticles of the virus along with exhaled air.

All people are susceptible to rotavirus infection, but children and the elderly, as well as patients with immunodeficiency conditions, most often get sick ( for example, patients with acquired immunodeficiency syndrome (AIDS)). The peak incidence occurs in the autumn-winter period, that is, at the same time when influenza epidemics are observed. Perhaps this was the reason for the people to call this pathology the stomach flu.

The mechanism of development of intestinal flu is as follows. Rotavirus penetrates the human digestive system and infects the cells of the intestinal mucosa, which normally ensure the absorption of food from the intestinal cavity into the blood.

Symptoms of the intestinal flu

Rotavirus infection manifests itself:

• Vomit. This is the first symptom of the disease, which is observed in almost all patients. The occurrence of vomiting is due to a violation of the absorption of food products and the accumulation of large volumes of food in the stomach or intestines. Vomiting with intestinal flu is usually single, but it can be repeated 1-2 more times during the first day of the disease, and then stops.
• diarrhea ( diarrhea). The occurrence of diarrhea is also associated with impaired absorption of food and the migration of a large amount of water into the intestinal lumen. The fecal masses released at the same time are usually liquid, foamy, they have a characteristic fetid odor.
• Pain in the abdomen. The occurrence of pain is associated with damage to the intestinal mucosa. The pains are localized in the upper abdomen or in the navel, are aching or pulling in nature.
• Rumbling in the stomach. It is one of the characteristic signs of intestinal inflammation. The occurrence of this symptom is due to increased peristalsis ( motility) intestines, which is stimulated by a large amount of unprocessed food.
• Symptoms of general intoxication. Patients usually complain of general weakness and fatigue, which is associated with a violation of the supply of nutrients to the body, as well as with the development of an acute infectious and inflammatory process. Body temperature rarely exceeds 37.5 - 38 degrees.
• Damage to the upper respiratory tract. May present with rhinitis inflammation of the nasal mucosa) or pharyngitis ( inflammation of the pharynx).

Treatment of the intestinal flu

Treatment for stomach flu includes:

• Recovery of water and electrolyte losses ( which are lost along with vomit and diarrhea). Patients are prescribed plenty of fluids, as well as special preparations containing the necessary electrolytes ( for example, rehydron).
• A sparing diet with the exception of fatty, spicy or poorly processed foods.
• Sorbents ( activated charcoal, polysorb, filtrum) - drugs that bind various toxic substances in the intestinal lumen and contribute to their removal from the body.
• Preparations that restore the intestinal microflora ( linex, bifidumbacterin, hilak forte and others).
• Anti-inflammatory drugs ( indomethacin, ibuphen) are prescribed only with a pronounced intoxication syndrome and an increase in body temperature of more than 38 degrees.

Influenza Diagnosis

Additional studies are prescribed only in severe cases, as well as to identify possible complications from various organs and systems.

Which doctor should I contact with the flu?

If the patient's condition is very severe ( that is, if the symptoms of general intoxication do not allow him to get out of bed), you can call a doctor at home. If the general condition allows you to visit the clinic yourself, you should not forget that the influenza virus is extremely contagious and can easily be transmitted to other people when traveling by public transport, while waiting in line at the doctor's office and under other circumstances. To prevent this, a person with flu symptoms should always put on a medical mask before leaving the house and do not remove it until returning home. This preventive measure does not guarantee 100% safety for others, however, it significantly reduces the risk of their infection, since the viral particles exhaled by a sick person linger on the mask and do not enter the environment.

It is worth noting that one mask can be used continuously for a maximum of 2 hours, after which it must be replaced with a new one. It is strictly forbidden to reuse a mask or take an already used mask from other people ( including from children, parents, spouses).

Is hospitalization necessary for the flu?

Hospitalization of patients with influenza may be required only if the patient's condition is extremely serious ( for example, with an extremely pronounced intoxication syndrome), as well as with the development of serious complications from various organs and systems. Children who develop convulsions against the background of elevated temperature are also subject to mandatory hospitalization. In this case, the probability of recurrence ( re-occurrence) convulsive syndrome is extremely high, so the child should be under the supervision of doctors for at least a few days.

If the patient is hospitalized during the acute period of the disease, he is sent to the infectious diseases department, where he is placed in a specially equipped ward or in a box ( insulator). Visiting such a patient is prohibited during the entire acute period of the disease, that is, until the release of viral particles from his respiratory tract stops. If the acute period of the disease has passed, and the patient is hospitalized due to developing complications from various organs, he can be sent to other departments - to the cardiology department for heart damage, to the pulmonology department for lung damage, to the intensive care unit for severe impairment of vital functions. important organs and systems, and so on.

In diagnosing influenza, a doctor may use:

• clinical examination;
• general blood analysis ;
• general urine analysis ;
• nasal swab analysis;
• sputum analysis;
• analysis for the detection of antibodies to the influenza virus.

clinical examination for influenza

Clinical examination includes:

• Inspection. During the examination, the doctor visually assesses the patient's condition. In the first days of the development of influenza, marked hyperemia is noted ( redness) mucous membranes of the pharynx, due to the expansion of blood vessels in it. After a few days, small pinpoint hemorrhages may appear on the mucosa. There may also be redness of the eyes and tearing. In severe cases of the disease, pallor and cyanosis of the skin can be observed, which is associated with damage to the microcirculation and a violation of the transport of respiratory gases.
• Palpation ( probing). On palpation, the doctor can assess the condition of the lymph nodes of the neck and other areas. With influenza, enlargement of the lymph nodes usually does not occur. At the same time, this symptom is characteristic of an adenovirus infection that causes ARVI and proceeds with a generalized increase in the submandibular, cervical, axillary and other groups of lymph nodes.
• percussion ( tapping). With the help of percussion, the doctor can examine the patient's lungs and identify various complications of influenza ( e.g. pneumonia). During percussion, the doctor presses the finger of one hand to the surface of the chest, and taps it with the finger of the other hand. By the nature of the resulting sound, the doctor draws conclusions about the condition of the lungs. So, for example, healthy lung tissue is filled with air, as a result of which the resulting percussion sound will have a characteristic sound. As pneumonia develops, the lung alveoli become filled with white blood cells, bacteria, and inflammatory fluid ( exudate), as a result of which the amount of air in the affected area of ​​\u200b\u200bthe lung tissue decreases, and the resulting percussion sound will have a dull, muffled character.
• auscultation ( listening). During auscultation, the doctor applies the membrane of a special device ( phonendoscope) to the surface of the patient's chest and asks him to take a few deep breaths and exhalations. By the nature of the noise generated during breathing, the doctor draws conclusions about the state of the pulmonary tree. So, for example, with inflammation of the bronchi ( bronchitis) their lumen narrows, as a result of which the air passing through them moves at high speed, creating a characteristic noise, which is assessed by the doctor as hard breathing. At the same time, with some other complications, breathing over certain areas of the lung may be weakened or completely absent.

Complete blood count for influenza

General analysis for influenza reveals:

• Change in the total number of leukocytes ( norm - 4.0 - 9.0 x 10 9 / l). Leukocytes are cells of the immune system that protect the body from foreign viruses, bacteria and other substances. When infected with the influenza virus, the immune system is activated, which is manifested by increased division ( breeding) leukocytes and the entry of a large number of them into the systemic circulation. However, a few days after the onset of the clinical manifestations of the disease, the majority of leukocytes migrate to the focus of inflammation to fight the virus, as a result of which their total number in the blood may slightly decrease.
• Increase in the number of monocytes. Under normal conditions, monocytes account for 3 to 9% of all leukocytes. When the influenza virus enters the body, these cells migrate to the site of infection, penetrate into infected tissues and turn into macrophages that directly fight the virus. That's why with the flu and other viral infections) the rate of formation of monocytes and their concentration in the blood increases.
• An increase in the number of lymphocytes. Lymphocytes are leukocytes that regulate the activity of all other cells of the immune system, and also take part in the processes of fighting foreign viruses. Under normal conditions, lymphocytes account for 20 to 40% of all leukocytes, but with the development of a viral infection, their number may increase.
• Decrease in the number of neutrophils ( norm - 47 - 72%). Neutrophils are cells of the immune system that fight off foreign bacteria. When the influenza virus enters the body, the absolute number of neutrophils does not change, however, due to an increase in the proportion of lymphocytes and monocytes, their relative number may decrease. It should be noted that with the addition of bacterial complications in the blood, a pronounced neutrophilic leukocytosis will be noted ( an increase in the number of leukocytes mainly due to neutrophils).
• Increased erythrocyte sedimentation rate ( ESR). Under normal conditions, all blood cells carry a negative charge on their surface, as a result of which they slightly repel each other. When blood is placed in a test tube, it is the severity of this negative charge that determines the rate at which erythrocytes will settle to the bottom of the test tube. With the development of an infectious-inflammatory process, a large number of so-called proteins of the acute phase of inflammation are released into the bloodstream ( C-reactive protein, fibrinogen and others). These substances contribute to the adhesion of red blood cells to each other, as a result of which the ESR increases ( more than 10 mm per hour in men and more than 15 mm per hour in women). It is also worth noting that ESR may increase as a result of a decrease in the total number of red blood cells in the blood, which can be observed with the development of anemia.

Urinalysis for influenza

Nose swab for influenza

With conventional microscopic examination, the virus cannot be detected, since its dimensions are extremely small. Also, viruses do not grow on conventional nutrient media, which are intended only for the detection of bacterial pathogens. For the purpose of cultivation of viruses the method of their cultivation on chicken embryos is used. The technique of this method is as follows. First, a fertilized chicken egg is placed in an incubator for 8 to 14 days. Then it is removed and the test material is injected into it, which may contain viral particles. After that, the egg is again placed in the incubator for 9-10 days. If there is an influenza virus in the test material, it invades the cells of the embryo and destroys them, as a result of which the embryo itself dies.

Flu sputum analysis

Influenza antibody test

There are many methods for detecting antiviral antibodies, but the hemagglutination inhibition test ( RTGA). Its essence is as follows. Plasma is placed in a test tube liquid part of blood) of a patient to which a mixture containing active influenza viruses is added. After 30-40 minutes, chicken erythrocytes are added to the same test tube and further reactions are observed.

Under normal conditions, the influenza virus contains a substance called hemagglutinin, which binds red blood cells. If chicken erythrocytes are added to the mixture containing the virus, under the action of hemagglutinin, they will stick together, which will be visible to the naked eye. If, on the other hand, plasma containing antiviral antibodies is first added to the virus-containing mixture, they ( antibody data) will block hemagglutinin, as a result of which agglutination will not occur with the subsequent addition of chicken erythrocytes.

Differential diagnosis of influenza

With influenza, differential diagnosis is carried out:

• with adenovirus infection. Adenoviruses also infect the mucous membranes of the respiratory tract, causing the development of SARS ( acute respiratory viral infections). The intoxication syndrome that develops in this case is usually moderately expressed, but the body temperature can rise to 39 degrees. Also an important distinguishing feature is an increase in the submandibular, cervical and other groups of lymph nodes, which occurs in all forms of acute respiratory viral infections and is absent in influenza.
• With parainfluenza. Parainfluenza is caused by the parainfluenza virus and also occurs with symptoms of damage to the mucous membrane of the upper respiratory tract and signs of intoxication. At the same time, the onset of the disease is less acute than with influenza ( symptoms may appear and progress over several days). Intoxication syndrome is also less pronounced, and body temperature rarely exceeds 38-39 degrees. With parainfluenza, an increase in the cervical lymph nodes can also be observed, while damage to the eyes ( conjunctivitis) does not occur.
• With respiratory syncytial infection. This is a viral disease characterized by damage to the lower respiratory tract ( bronchi) and moderate symptoms of intoxication. Mostly children of primary school age get sick, while in adults the disease is extremely rare. The disease proceeds with a moderate increase in body temperature ( up to 37 - 38 degrees). Headaches and muscle pain are rare, and eye damage is not observed at all.
• with rhinovirus infection. This is a viral disease characterized by damage to the nasal mucosa. It is manifested by nasal congestion, which is accompanied by copious secretions of a mucous nature. Sneezing and dry cough are often noted. Signs of general intoxication are very mild and may manifest as a slight increase in body temperature ( up to 37 - 37.5 degrees), weak headaches, poor exercise tolerance.

Influenza is an acute disease with a short incubation period, a sudden onset and a cyclic course, which is characterized by severe toxicosis and damage to the upper respiratory tract and lungs.

The duration of the incubation period for influenza ranges from several hours to 3 days, most often it is 1-2 days.

The influenza clinic can vary significantly depending on the age of the patients, the state of the immune system, the serotype of the virus, its virulence, and the like. It is advisable to consider the following clinical forms of influenza: common (typical) and atypical (afecile, acatarrhal); according to the presence of complications - uncomplicated and complicated. The severity of uncomplicated influenza is determined by the severity and duration of intoxication.

The typical course of the flu

In the clinical picture, two main syndromes are distinguished: intoxication and catarrhal (with damage to the respiratory tract).

Intoxication syndrome

The symptoms of intoxication come to the fore: chills or chilliness, a sharp headache with overwhelming localization in the frontal region and temples, aching muscles, sometimes in the joints, pain when moving the eyeballs or when pressing on them, photophobia, lacrimation, severe weakness and fatigue , lethargy; these symptoms on the first day of the disease dominate the catarrhal syndrome. Weakness in severe cases can reach adynamia. Often it is accompanied by dizziness and fainting.

Already in the first hours of the disease, the body temperature reaches a maximum of 39-40°C. The level of fever reflects the degree of intoxication, but in general these concepts cannot be identified.

Sometimes at a sufficiently high temperature, signs of intoxication are not pronounced, which is mainly observed in young patients with influenza, which is caused by the A (H1N1) virus. Their hyperthermia is short-term, and in the future the disease manifests itself as a moderate degree of severity. The temperature reaction in influenza is acute and relatively short-lived. The fever lasts for 2 to 5 days in influenza A, a little longer in influenza B, and then the temperature decreases by accelerated lysis. In 10-15% of patients, fever has a two-wave character, which is associated with complications caused by the bacterial flora, or exacerbation of chronic diseases.

Headache is the main sign of intoxication and one of the first symptoms of the disease. The pain is usually localized in the frontal region, especially in the region of the superciliary arches, sometimes it is retroorbital in nature. In elderly patients, headache is often diffuse, its degree may vary, but in most cases it is moderate.

Severe headache in combination with insomnia, delirium, repeated vomiting is observed in patients with a severe course of the disease, may be accompanied by meningeal syndrome. In the study of cerebrospinal fluid changes are not detected. In adults, unlike children, seizures rarely occur.

catarrhal syndrome

It is one of the two leading syndromes, often receding into the background. In some cases, it is insufficiently expressed or completely absent. It is manifested by dryness and a sensation of perspiration in the throat, nasal congestion. But the most typical symptom of catarrhal syndrome is tracheobronchitis. It is manifested by a feeling of perspiration or pain behind the sternum, which is due to the inflammatory process of the mucous membrane of the trachea and bronchi, a rough, hacking cough, sometimes paroxysmal with a small amount of sputum. This can lead to an increase in pressure in the system of the superior vena cava and, in case of increased fragility of blood vessels, can contribute to manifestations of hemorrhagic syndrome (nosebleeds, small hemorrhages in the mucous membrane of the oropharynx, sometimes on the skin). During an uncontrollable dry cough that joins vomiting, there are very severe pains in the upper sections of the rectus abdominis muscles and intercostal muscles along the line of attachment of the diaphragm to the chest. Subsequently, the cough becomes wet. Often joins hoarseness, a feeling of squeezing in the chest. Some experts believe that "scratching" pain behind the sternum is a pathognomonic sign of the flu. The catarrhal syndrome lasts about 7-10 days, the cough lasts the longest.

During an objective examination of patients in the first days of influenza, hyperemia and swelling of the face, hyperemia of the neck, injection of blood vessels of the sclera, eye moisture, lacrimation, and moderate conjunctivitis are noted. These symptoms combined resemble the face of a crying baby. From the 3-4th day of illness, herpetic eruptions may appear on the lips, wings of the nose. In severe cases of the disease, pallor of the skin with a cyanotic tint is observed (as manifestations of hypoxia and hypoxemia).

On the mucous membrane of the palate, arches, posterior pharyngeal wall, there is a bright hyperemia, which in patients with severe course has a cyanotic hue (due to circulatory disorders), the injection of the vessels of the soft palate is more pronounced. In some patients, the granularity of the soft palate is revealed, less often - the tongue and arches. The posterior pharyngeal wall is dryish in appearance and has enlarged lymphatic follicles. By the 3-4th day of the disease, the hyperemia of the mucous membranes decreases and only the injection of blood vessels remains. Against this background, the granularity of the soft palate becomes more noticeable and petechial hemorrhages are often noticeable.

The mucous membrane of the nose is usually hyperemic with a cyanotic tint, edematous, therefore, from the first day of the disease, nasal breathing is difficult, but the amount of discharge from the nose is small. There may be plethora and swelling of the lower conchas of the nose, dryness, and sometimes bleeding of the mucous membrane. Later, as noted, mild serous or mucous discharge appears. Abundant rhinorrhea for influenza is not characteristic. The tongue is moist, evenly lined with a thin white coating. Sometimes there may be a slight increase in the cervical lymph nodes, but usually lymphadenopathy is not characteristic.

The defeat of the respiratory system with influenza is natural. In the feverish period, there may be shortness of breath. With percussion of the lungs, a box sound is often detected. On auscultation of the lungs (in the absence of complications), breathing is vesicular, with a hard tone, sometimes single dry rales are heard. On Rg-grams, an increase in the vascular pattern is visualized, an expansion of the roots of the lungs, which can be mistakenly diagnosed as pneumonia.

On the part of the cardiovascular system, the following changes are noted: the pulse at first more often corresponds to temperature, relative bradycardia or tachycardia is less often noted. Persistent tachycardia at the height of the disease is prognostically unfavorable, especially in elderly and senile patients with chronic diseases of the heart, blood vessels and respiratory apparatus. In many patients muffled heart sounds are heard, especially in severe forms of the disease. In older patients, unlike young ones, complaints of pain in the heart area, angina pectoris attacks are possible. Arterial pressure during the height of the disease tends to decrease. The ECG reveals changes typical of toxicosis: a decrease and serration of the P wave, a decrease in the T wave in various leads, a relative lengthening of the Q-T interval, and a lengthening of the P-Q interval. This indicates diffuse toxic damage to the myocardium. The described changes disappear within 1-2 weeks. However, the nature of myocardial damage in influenza has not yet been elucidated. Some researchers consider it as a manifestation of influenza myocarditis, the second attribute changes in the heart to nonspecific dystrophic disorders, and others attach primary importance to vascular lesions.

The use of echocardiography in the dynamics of influenza expands the prevailing views on the nature of myocardial changes in this infection. Echocardiography allows to detect changes in the myocardium in cases where it is not possible to diagnose changes in the myocardium clinically and by means of ECG. Echocardiographic changes are manifested by such signs: a moderately pronounced expansion of the ventricular cavities (mainly the right one), the appearance of local disturbances in the contractile function of the myocardium, changes in central hemodynamics with a tendency to hyperkinetic type. The basis of these processes is the deterioration of blood circulation in a small circle, an increase in pressure in a. pulmonalis as a result of an increase in peripheral resistance in the vessels of the lungs, an increase in the load on the right heart.

Changes in the gastrointestinal tract are not typical for influenza. In severe forms, appetite is reduced up to anorexia. The tongue remains moist, covered with a white coating. The abdomen is soft, painless on palpation. The liver and spleen are not enlarged. The stool is often delayed, it can rarely be loosened. Sometimes with such erroneous diagnoses as “influenza with intestinal syndrome”, “influenza intestinal form”, usually there is a pathology that is caused by adenoviruses or intestinal Coxsackie and ECHO viruses, shigella and salmonella, and sometimes the action of drugs. Sometimes short-term diarrhea with influenza can be associated with an exacerbation of chronic diseases of the gastrointestinal tract. These changes are nonspecific, they are associated with changes in the tone of the autonomic nervous system under the influence of toxins. The opinion of some doctors about the "intestinal form" of the flu is completely unfounded.

Damage to the central nervous system in a severe course of the disease is manifested by dizziness, sleep disturbance, vomiting, and manifestations of meningism. With damage to the peripheral nervous system, there are local hyperesthesias and paresthesias of the skin, trigeminal neuralgia, intercostal and other nerves. Especially often there are functional disorders of the autonomic nervous system in the form of facial flushing, sweating, pulse lability.

Clinical signs of damage to the urinary system in uncomplicated influenza are not detected.

From general clinical laboratory research with influenza, a complete blood count is important. On the first day, 1/3 of patients develop leukocytosis (up to 10-12x10 9 /l) with a moderate stab shift due to an increase in the number of circulating neutrophils. On the second day, the number of neutrophils rapidly decreases, leukopenia develops, which persists until the end of the fever period, and sometimes longer.

The dynamics of the content of lymphocytes in such patients is different. When volunteers were infected with influenza, a significant decrease in the number of lymphocytes in the circulating blood was detected several hours before the onset of the disease. Absolute lymphopenia is characteristic of influenza and is observed throughout the entire period of the disease. At the height of the disease, relative lymphocytosis (due to neutropenia) occurs. At the beginning of convalescence, there is a tendency to normalize the blood count. ESR in most cases remains close to normal. Indicators of hemoglobin, erythrocytes, hematocrit usually do not change.

The decrease in the level of neutrophils in the peripheral blood is explained by their migration to the focus of inflammation, as well as increased production of cortisol in a stressful situation, which is an influenza infection for the body.

Changes in urine are not typical. But at the height of the fever, slight proteinuria is possible as a result of toxicosis and circulatory disorders.

Based on the degree of toxicosis, the severity of the catarrhal syndrome, mild, moderate, severe and fulminant (fulminant, hypertoxic) forms of influenza are distinguished. The latter form is considered by many experts as a complication of influenza.

At mild form flu body temperature does not exceed 38 ° C and normalizes after 2-3 days. Symptoms of general intoxication and catarrhal syndrome are mild. In some cases, in the clinic, this form is not much different from acute respiratory infections of another etiology.

Moderate form influenza is characterized by an increase in body temperature up to 39 ° C, pronounced symptoms of intoxication and damage to the respiratory system. The fever lasts up to 4-5 days. This form of influenza is the most commonly reported.

Severe form influenza is manifested by the rapid development and significant severity of intoxication, fever and catarrhal phenomena. Characteristic:

• acute onset;
• high and longer fever (39-40°C) with pronounced intoxication;
• severe weakness up to complete adynamia;
• severe muscle pain and headache;
• drowsiness or insomnia, dizziness;
• possible delirium, hallucinations, loss of consciousness, convulsions;
• nausea, repeated vomiting;
• earthy skin tone;
• constant shortness of breath, aggravated by movement;
• positive pinch symptom;
• often develop meningeal and postencephalitic syndromes;
• respiratory complications are often observed, and first of all - viral-bacterial pneumonia.

Complicated forms of influenza

Lightning (hypertoxic) form.

An extreme manifestation of a severe form of influenza, which is characterized by severe neurotoxicosis with the development of cerebral edema; cardiovascular, respiratory failure (acute hemorrhagic pulmonary edema, bronchiolitis, stenosis of the larynx, etc.); progressive DVM syndrome; characterized by a rapidly progressive deterioration of the patient's condition, tachypnea, tachycardia, stabbing chest pains, "rusty" sputum, increased shortness of breath, cyanosis of the skin with a gray tint. There is an extreme severity and rapid course of the disease.

The most common syndrome in severe and complicated forms of influenza is acute respiratory failure (ARF). It may be due to:

• reduction of the respiratory surface of the lungs;
• obstruction of the bronchial tree with sputum;
• violation of diffuse properties;
• reduction of functioning areas (atelectasis, collapse);
• inadequate function of the respiratory muscles;
• violation in the surfactant system;
• dysfunction of the respiratory center or blockade of the afferent links in the regulation of the respiratory muscles;
• mismatch between ventilation and perfusion.

The main clinical signs of ARF are shortness of breath, acrocyanosis, sweating, tachycardia, respiratory rhythm disturbance and neuropsychic status, which depends on the degree of hypoxemia and hypercapnia, metabolic or mixed acidosis. The clinical picture of ARF is divided into three degrees.

I degree characterized by complaints of a feeling of lack of air, anxiety, euphoria. The skin is moist, pale, with slight acrocyanosis. There is increasing shortness of breath (25-30 breaths per minute), a moderate increase in blood pressure. Pa02 reduced to 70 mm Hg. Art., PaCO2 increased to 50 mm Hg. Art.

II degree. Delirium, agitation, hallucinations, profuse sweat, cyanosis (sometimes with hyperemia), significant shortness of breath (35-40 breaths per minute), tachycardia, arterial hypertension.

Pa02 reduced to 60 mm Hg. Art., PaCO2 increased to 60 mm Hg. Art.

III degree. There comes a coma with clonic and tonic convulsions, the pupils are wide, significant cyanosis, breathing is superficial, frequent (more than 40 per minute), and only before cardiac arrest does breathing become rare. BP is drastically reduced. Pa02 less than 50 mm Hg. Art., PaCO2 above 70 mm Hg. Art.

The second, no less frequent syndrome in severe and complicated forms of influenza is acute circulatory failure, which, in particular, develops in patients with infectious-toxic shock. The leading role in the development of this complication belongs to viral and bacterial toxins, which cause dysregulation of the peripheral circulation.

The ITSH clinic is divided into 3 stages.

1st stage:

• intoxication without clinical signs of shock. There are chills followed by an increase in temperature to febrile numbers, nausea, vomiting, possible diarrhea;
• hyperventilation - alkalosis (respiratory), cerebral disorders in the form of anxiety or lethargy;
• Blood pressure is normal or slightly reduced, sometimes it can be slightly elevated.

2nd stage:

• the stage of "warm hypertension", which is characterized by low peripheral resistance and high cardiac output;
• symptoms: tachycardia, tachypnea, hypotension, pallor of the extremities with acrocyanosis, oliguria and cerebral disturbances. The lethality of patients reaches 40%.

3rd stage:

• "cold hypotension" - shock with high peripheral resistance and low cardiac output;
• soporous state, which turns into a coma. The skin is pale, cold; may be a petechial rash. Tachycardia, tachypnea, oligoanuria. Violation of thermoregulation - hypothermia. Profound metabolic acidosis. The lethality of patients reaches 60%.

Depending on the phase and depth of shock, the minute volume of circulating blood may be normal, increased or decreased.

In the early stages of shock, a decrease in blood pressure leads to a compensatory increase in the tone of the sympathetic-adrenal system with an increase in blood levels of adrenaline and norepinephrine, which cause spasm of the vessels of parenchymal organs (liver, kidneys), intestines, and skeletal muscles. The result is the stabilization of blood pressure, improvement of blood circulation in the brain and heart.

In the late stages of shock, with insufficient compensatory mechanisms, vasospasm can lead to prolonged ischemia and the development of irreversible changes in tissues and the homeostasis system.

In the terminal phase of the disease, a complication such as brain swelling may occur, which is a consequence of brain tissue hypoxia, hypercapnia, metabolic acidosis, and hyperthermia. The first clinical manifestations are severe diffuse headache, dizziness, nausea, vomiting, the presence of meningeal signs, congestion in the fundus, loss of consciousness, convulsions, increased blood pressure, bradycardia. Bradycardia is the earliest, and oligopnea, on the contrary, is one of the latest symptoms of cerebral edema. When providing assistance to reduce intracranial pressure, a lumbar puncture is indicated, and this must be done very carefully, due to the danger of wedging the cerebellum or medulla oblongata into the foramen magnum.

Toxic hemorrhagic pulmonary edema may appear already in the first days of illness and be the cause of death in severe and fulminant forms of influenza. Against the background of severe intoxication, shortness of breath appears, cyanosis increases; respiratory failure is accompanied by excitation. An admixture of blood appears in the sputum, although this admixture does not cause the development of hemorrhagic pulmonary edema. During auscultation of the lungs, a significant number of different-sized moist rales is heard; shortness of breath, tachycardia increases. In such cases, death occurs very quickly with symptoms of severe respiratory failure.

Swelling of the vocal cords, reflex spasm of the muscles of the larynx can lead to the development of a false croup. This condition occurs in children and young adults and is characterized by the sudden onset of an asthma attack. The attack usually occurs at night, accompanied by anxiety, tachycardia. If you do not provide urgent assistance, the disease can end in death.

A wide variety of changes in the heart muscle - from mild myocarditis, which are detected only on the ECG, to, although rarely, myocardial infarction - can cause vascular disorders. A significant role in the development of such complications is played by the severe course of influenza, the age of the patient. At a later date, endocarditis of an infectious-allergic genesis may occur.

Flu complications can be caused by bacterial flora. More often they appear after the 4-5th day of illness, sometimes even earlier. The most characteristic of them is pneumonia of a diverse nature: focal, segmental, confluent. The very presence of viral pneumonia is not recognized by everyone. It is assumed that viruses cause a violation in the system of local defense of the lungs (T-cell deficiency, impaired phagocytic activity, damage to the ciliary apparatus), which contributes to the occurrence of bacterial pneumonia. Viral (or "postviral") pneumonia is often not recognized even in patients who have a "protracted course" of acute respiratory viral infections, develop signs of bronchial obstruction, and changes in the blood are detected. Such patients are often diagnosed with residual effects of an acute respiratory viral infection. The clinical picture is dominated by manifestations of the corresponding viral infection - influenza. Physical and radiological symptoms in viral pneumonia are generally scanty.

Clinically, pneumonia is manifested by a cough, and a dry flu-like cough is often replaced by a cough with sputum (mucopurulent, purulent). Often patients complain of chest pain, shortness of breath. Objectively, a change in percussion sound is determined over the focus of inflammation; against the background of weakened breathing, crepitus or small bubbling rales are heard. The right lung is most commonly affected.

The severe course of such a complication is more often observed with pneumonia that occurs in the first days of an influenza infection, in contrast to pneumonia that develops at a later date. Pneumonia caused by staphylococcus aureus is especially severe and is known to be prone to abscess formation in debilitated patients. The etiological factor of pneumonia can be another flora (enterobacteria, streptococci, pneumococci, Haemophilus influenzae).

Severe forms of pneumonia can complicate adult respiratory distress syndrome (ARDS), which has a high mortality rate of up to 60%. ARDS is known to have three stages:

1. preclinical, which is characterized by morphological signs of damage to the capillaries of the alveolar membranes;
2. the acute stage, which develops during the first week after the action of the damaging factor, is characterized by the development of interstitial and alveolar edema, inflammatory changes with a large number of polymorphonuclear leukocytes and fibrin both in the exudate inside the alveoli and in tissue infiltrates, hyaline membranes;
3. the stage of organization of exudate and proliferation of second-order pneumocytes, which lead to interstitial fibrosis. The processes of organization begin from the 2-3rd day of the disease.

There are 4 periods in the clinical picture of RDSD.

I period - hidden, or the period of action of the etiological factor (lasts about 24 hours). In this period there are no clinical and radiological manifestations. However, tachypnea (more than 20 breaths per minute) is often observed.

II period - initial changes that occur on the 1st-2nd day from the onset of the etiological factor. The main clinical symptoms of this period are moderate dyspnea and tachycardia. Auscultation of the lungs may reveal harsh vesicular breathing and scattered dry rales. On radiographs of the lungs, there is an increase in the vascular pattern, mainly in the peripheral regions. These changes indicate the onset of interstitial pulmonary edema. The study of the gas composition of the blood either has no deviations from the norm, or a moderate decrease in Pa02 is detected.

III period - deployed, or the period of pronounced clinical manifestations, which is characterized by severe symptoms of acute respiratory failure. Severe shortness of breath appears, auxiliary muscles take part in the act of breathing, swelling of the wings of the nose and retraction of the intercostal spaces are clearly visible, pronounced diffuse cyanosis is observed. During auscultation of the heart, tachycardia and deafness of heart tones are noted, arterial pressure is significantly reduced.

Percussion of the lungs reveals dullness of percussion sound, more in the posterior lower sections, auscultatory - hard breathing, hard wheezing can be heard. The appearance of wet rales and crepitus indicates the appearance of fluid in the alveoli (alveolar pulmonary edema of varying degrees).

X-rays of the lungs reveal pronounced interstitial pulmonary edema, as well as bilateral infiltrative shadows of irregular cloud-like shape, which merge with the root of the lungs and with each other. Very often, in the marginal sections of the middle and lower lobes, against the background of an enhanced vascular pattern, foci-like shadows appear.

Characteristic for this period is a significant drop in Pa02 (less than 50 mm Hg, despite oxygen inhalation).

IV period - terminal. It is characterized by a pronounced progression of respiratory failure, the development of severe arterial hypoxemia and hypercapnia, metabolic acidosis, the formation of acute cor pulmonale as a result of increasing pulmonary hypertension.

The main clinical symptoms of this period are:

• severe shortness of breath and cyanosis;
• profuse sweating;
• tachycardia, deafness of heart tones, often various arrhythmias;
• a sharp drop in blood pressure up to collapse;
• cough with pink frothy sputum;
• a large number of wet rales of various calibers in the lungs, abundant crepitus (signs of alveolar pulmonary edema);
• development of signs of increasing pulmonary hypertension and acute pulmonary heart syndrome (splitting and accent of II tone on the pulmonary artery; ECG signs - high spike P waves in leads II, III, avL, VI-2; pronounced deviation of the electrical axis of the heart to the right; radiographic signs of an increase pressure in the pulmonary artery, protrusion of its cone);
• development of multiple organ failure (impaired kidney function, which is manifested by oligoanuria, proteinuria, cylindruria, microhematuria, increased blood levels of urea, creatinine; impaired liver function in the form of mild jaundice, a significant increase in blood levels of alanine aminotransferase, fructose-1-phosphate aldolase, lactate dehydrogenase; dysfunction of the brain in the form of lethargy, headache, dizziness, clinical signs of cerebrovascular accident are possible).

The study of the gas composition of the blood reveals deep arterial hypoxemia, hypercapnia; study of acid-base balance - metabolic acidosis.

With influenza, the development of arachnoiditis is also possible. Its development is based on a violation of cerebrospinal fluid dynamics as a result of hyperproduction of cerebrospinal fluid and damage to blood vessels with the formation of a focal adhesive process that disrupts the absorption of cerebrospinal fluid by the venous network, which, in turn, increases the violation of CSF circulation. Clinical manifestations of this process are regularly recurring attacks of headache, dizziness, as well as nausea, weakness. These symptoms may appear as early as 2-3 weeks after the flu.

A severe course of influenza, especially in persons with a burdened history (hypertension, atherosclerosis), may be accompanied by hemorrhage in the brain tissue, followed by the development of paralysis.

Guillain-Barré syndrome can also occur with the flu. It is characterized by the development of peripheral paralysis of the muscles of the limbs while maintaining superficial sensitivity. The process can spread from the bottom up with damage to the muscles of the face, pharynx, larynx. In the cerebrospinal fluid, protein-cell dissociation is detected. Fortunately, this syndrome is very rare. Allow infectious-allergic genesis of its development.

Damage to the nervous system during influenza can also be represented by sciatica, neuralgia of various localization, polyneuritis. These complications develop more often already in the period of convalescence and can last from several days to several weeks.

A peculiar and infrequent complication of influenza is Reye's syndrome, which was described as early as 1963. It is characterized by the development of acute encephalopathy and fatty degeneration of internal organs. More often, Reye's syndrome is associated with influenza A and occurs almost exclusively in children under the age of 16 years. This complication begins after the extinction of the clinic of the underlying disease in the period of initial convalescence. The first symptom is sudden vomiting. Encephalopathy, which then grows, is manifested by increased agitation, extreme irritability, aggressiveness, but at the same time there are bright intervals of adequate behavior. This syndrome can develop very quickly: sometimes within a few hours after the onset of vomiting, the child quickly falls into a coma. In 30% of patients at the very beginning of the disease, a slight increase in the liver is also detected, but jaundice does not develop. This is characterized by an increase in the activity of transaminases and an increase in the concentration of ammonia in the blood in combination with hypoglycemia. It is important to note that Reye's syndrome is difficult to differentiate from acute encephalopathies of other etiologies. The diagnosis is considered unquestionable only after it is confirmed by the results of a liver biopsy. In patients, violations of amino acid and fat metabolism are detected. The reasons for the development of the syndrome remain unknown. Possible genetic predisposition. The only thing that is unquestionable is that a previous viral infection is a prerequisite for the development of the disease. Mortality is very high and is 20-56%.

The presence of symptoms of vegetative dystopia and general asthenia is one of the most characteristic features of influenza infection. Usually, all these disorders quickly disappear after the temperature normalizes, but in some patients they persist after the extinction of all clinical manifestations of the infection, sometimes up to a month, that is, they acquire the character of an influenza complication. Symptoms of asthenia (general weakness, sweating, poor sleep, decreased appetite, insomnia, increased fatigue, distracted attention) are combined with pulse lability, unstable blood pressure, and frequent heartbeats. Often there are violations of the emotional sphere (patients become whiny, irritated). In this regard, the concept of “post-viral asthenia syndrome” (SAS) was formed in medicine, which was described back in the 60s by P. Kendell. Asthenia is associated with the action of a biological agent. Many researchers believe that the long-term persistence of viruses is most likely the main reason for the development of SPA. Viremia is accompanied by infection of macrophages and other subpopulations of lymphocytes, which remain carriers of the pathogen for a long time, which forms the development of immunosuppression. SPA often occurs within a month after a viral illness. The duration of this syndrome can be years and depends both on the persistent virus itself, and on the state of the macroorganism and its immune system, as well as on the quality of the treatment of the viral infection that has been carried out.

SPA can also be accompanied by mental disorders - from mild depression to significant behavioral disorders. Neurological symptoms in SPA include sensory impairment, autonomic disorders and myalgia. Often patients are concerned about hyperesthesia in the form of "socks and gloves", a slight subfebrile increase in body temperature.

The phenomenon of neuromyalgia attracts the greatest attention. Pain occurs in an isolated muscle group and is accompanied by muscle weakness and fatigue even with little physical exertion.

The results of clinical analyzes of urine and blood fluctuate within the normal range, and serological examination often makes it possible to diagnose a previous viral infection. An assessment of the immune status indicates a change in the function of lymphocytes, a change in the complement system, as well as suppressor cells. The transferred influenza causes inhibition of the activity of macrophages and neutrophils, in connection with which a syndrome of phagocytosis dysfunction is formed. Against such a background, unmotivated fatigue, an increase in emotional lability cause a misunderstanding in the doctor, who regards them as aggravation.

In addition to the central nervous system, complications from other internal organs are also possible. Thus, sensitization of the mucous membrane of the trachea and bronchi directly by the influenza virus and the decay products of cells infected with the virus is the basis for the development of bronchial asthma. Kidney sensitization by this virus, its antigens, immune complexes underlies the development of glomerulonephritis 1-2 months after the illness. The reliability of the occurrence of such a complication should be determined by the doctor, who, in order to prevent it, may recommend that the patient avoid hypothermia in the coming months.

Vasculitis is the basis of long-term residual effects after the flu.

The transferred influenza, given the decrease in immunological reactivity (anergy), can lead to an exacerbation of chronic diseases that the patient had: tuberculosis, rheumatism, tonsillitis, cholecystocholangitis, pyelonephritis, and the like.

Separately, it should be noted the possibility of influenza complications in pregnant women, which in the II and III trimesters of pregnancy can lead to miscarriages, stillbirths and congenital defects. They can develop 9-14 days after the flu. If a woman has been ill with the flu in the first half of pregnancy, then the child's risk of developing schizophrenia is significantly increased in the future.

Influenza in different age groups

There are some features of the influenza clinic in different age groups.

At young children symptoms of neurotoxicosis with repeated vomiting, meningism, convulsions against the background of subfebrile or normal body temperature may come to the fore. Sometimes such patients develop bronchiolitis, laryngitis, croup. Cough with croup is rough, barking, breathing is noisy, there is tension from the auxiliary respiratory muscles. Unlike diphtheria croup, the phenomena of stenosis of the larynx are weakly expressed.

For the elderly and senile influenza is dangerous primarily because chronic cardiovascular and respiratory diseases are exacerbated against its background, other chronic foci are activated. Clinically, these patients have a state of hyperactivity. Influenza occurs in patients of this group more often with low body temperature, but with severe symptoms of intoxication, complicated by severe pneumonia. Increased susceptibility to other diseases.

convalescence

Fever in uncomplicated influenza is short-term and ranges from 2 to 5 days, much less often - 6-7 days. Body temperature decreases critically or accelerated lysis, accompanied by sweating. In the future, subfebrile condition may persist. Reducing and even normalizing body temperature does not mean recovery from influenza. From the moment the temperature drops, the general condition of patients improves, the intoxication syndrome quickly decreases. Headaches, catarrhal phenomena disappear, appetite resumes and sleep improves. By this time, the cough becomes softer, mucous sputum appears, which alleviates it, the feeling of tickling behind the sternum disappears. Usually, the cough, gradually subsiding, lasts another 2-4 days, but if it persists longer and purulent sputum appears, this is already an indicator of the occurrence of a bacterial complication.

The convalescence period for influenza lasts 1-2 weeks. Many convalescents have asthenia that lasts from several days to 2-3 weeks (fatigue, irritability, sleep disturbance, sweating, sensory excitability to light, sound). Diencephalic disorders may appear - low-grade fever, vestibular disorders.

Mostly the flu ends with a full recovery. In recent decades, influenza mortality has not exceeded 1-3 cases per 100,000 population. But there is the so-called "adjusted mortality" during epidemics, which is not directly related to influenza and ranges from 76.7 to 540 cases per 100,000 population in different countries. The risk group, as already noted, primarily includes elderly and senile people with diseases of the cardiovascular system and chronic inflammatory processes. For example, it is known that hypertensive crises and acute disorders of cerebral circulation are more likely to occur in patients with hypertension during the period of influenza.

It should be noted that a feature of the influenza infection is also its ability to "show" secret foci of infection, regardless of their location (inflammatory diseases of the urinary, nervous system, etc.). Accession of a secondary infection at any stage of the disease (high, convalescence) significantly worsens the patient's condition, increases the frequency of adverse outcomes. On this occasion, French clinicians even say that "influenza pronounces a sentence, and the bacterial flora carries it out."

Outcomes of the disease in the direction of virus carriers have not been studied enough. It is known that the immunodeficiency state of the body contributes to the formation of the persistence of the influenza virus. It is still necessary to establish whether immunodeficiency is the main and necessary condition for such an outcome of the disease.

Due to the lack of clear criteria for distinguishing between moderate and severe influenza, dynamic active monitoring of the patient is necessary the day after the initial examination and in the future. If high temperature and intoxication persist, there is no improvement and complications of the disease are detected, the patient is subject to mandatory hospitalization in an infectious diseases hospital.

is an acute, severe disease caused by a viral infection. The influenza virus is included in the group (acute respiratory viral infections), but due to the severity of the course, as a rule, it is considered separately. Influenza affects the upper respiratory tract, trachea, bronchi, and sometimes the lungs, causing a runny nose, cough, toxicosis; The disease can lead to serious complications and even death. Influenza is most dangerous for those whose body is weakened. Children, the elderly, and those with chronic illnesses are particularly susceptible to the flu.

Causes of the Flu

The flu is caused by a viral infection. Three types of influenza virus have been isolated.

Type A virus capable of infecting both humans and animals. "Bird flu", "swine flu" are varieties of type A virus. A virus of this type causes diseases of moderate or severe severity that become epidemic. Epidemics of influenza A occur with a frequency of 2-3 years. The insidiousness of the virus lies in the fact that it is able to mutate - to change its antigenic structure.

Type B virus is transmitted only from person to person. Although this type is also modified, it does not cause such severe epidemics. Influenza B outbreaks are usually localized. The frequency of such outbreaks is 4-6 years. They may precede or overlap with influenza A epidemics.

Type C virus little studied. It is also transmitted only from person to person, but does not cause severe symptoms (in some cases, infection does not cause symptoms at all).

The main route of infection transmission is airborne. However, a household way is also possible - through household items. The virus enters the air with particles of mucus, saliva or sputum emitted when coughing or sneezing. The zone in which the risk of infection is quite high is usually 2-3 m around the patient. At a greater distance, the concentration of aerosol particles is negligible and does not pose a threat.

Flu Complications

Influenza is dangerous, in particular, the complications that it can cause. Therefore, it is so important to carry out the treatment of influenza under the supervision of a physician. Usually, the prescribed course of treatment and diagnostic procedures are aimed precisely at eliminating the possibility of complications. Sometimes it is the experience and qualifications of a doctor that help to detect a complication in time and start appropriate treatment.

The most common complications of influenza are:

• (pneumonia);
• inflammation of the membranes of the brain (meningitis, arachnoiditis);
• other complications from the nervous system (polyneuritis, sciatica, neuralgia);
• complications from the cardiovascular system (pericarditis, myocarditis);
• kidney complications.

flu symptoms

The incubation period for influenza is about 2 days. The disease begins acutely: the temperature rises, the head begins to hurt (these are symptoms of intoxication), catarrhal signs of the disease appear. High fever and other manifestations of intoxication usually last up to 5 days. If the temperature does not subside after 5 days, bacterial complications should be assumed.

Catarrhal phenomena last a little longer - up to 7-10 days. After their disappearance, the patient is considered recovered, but for another 2-3 weeks, the consequences of the disease may be observed: weakness, irritability, headache, possibly insomnia.

If you have the flu, be sure to call your doctor. It is dangerous to treat influenza without contacting a specialist; you can miss the development of complications. And in a severe course of the disease, timely professional medical care is absolutely necessary, sometimes it is just a matter of saving lives.

On the severe or complicated flu indicate the following symptoms:

• temperature above 40°C;
• maintaining a high temperature for more than 5 days;
• severe headache that is not relieved by conventional painkillers;
• shortness of breath or abnormal breathing;
• convulsions, impaired consciousness;
• the appearance of a hemorrhagic rash.

Symptoms of intoxication

Intoxication with influenza manifests itself primarily as:

• . In mild influenza, the temperature may not rise above 38 ° C, but for moderate influenza, a temperature of 39-40 ° C is typical, and in severe illness it can be even higher;
• chills;
• (mainly in the forehead and eyes);
• joint and muscle pain;
• in some cases - and .

Catarrhal symptoms

Typical catarrhal symptoms of influenza are:

• dryness and sore throat (examination reveals redness of the throat);
• cough . In the uncomplicated course of the flu, as a rule, a dry throat cough is observed. But in some cases, the infection can go down and cause inflammation of the bronchi (bronchitis) and lungs (). Smokers, people with a weakened immune system, as well as patients suffering from bronchial asthma and pulmonary diseases are predisposed to a similar course of the disease;

Hemorrhagic phenomena

Hemorrhagic phenomena in influenza are observed in 5-10% of cases. It:

• hemorrhages in the mucous membranes (eyes, mouth);
• nosebleeds;
• hemorrhages on the skin (in severe disease).

Influenza treatments

Treatment of influenza, which occurs without complications, is carried out at home. As a rule, in the treatment of influenza are prescribed:

• plentiful drink;
• antipyretics;
• means that support immunity;
• drugs that relieve catarrhal symptoms (vasoconstrictor to facilitate nasal breathing, antitussives);
• antihistamines in case of an allergic reaction.

However, the treatment of influenza should be carried out as directed by a doctor, since much depends on the stage of the disease, its severity, the condition of the body, etc.

Specialist consultation

When flu symptoms appear (first of all, a high temperature attracts attention), a doctor should be called to the patient. By contacting JSC "Family Doctor", you can call a therapist to the house of an adult, and a pediatrician to a child.

Flu Prevention

Prevention of influenza, first of all, involves limiting contact with sick people. It is necessary to prevent the virus from entering the mucous membranes of the nose, mouth or eyes. When touching objects that may contain the virus (patient's household items), you should wash your hands thoroughly.

Strengthening the immune system reduces the risk of influenza and other acute respiratory viral infections. This is facilitated by proper nutrition, a measured lifestyle, exercise, walks in the fresh air, the elimination of stress, healthy sleep. Since smoking reduces immunity, it is advisable to stop smoking.

In the event of an outbreak of influenza in the team or an epidemic threat, it is advisable to take prophylactic antiviral agents. However, before you start taking it, you should consult your doctor.

Influenza vaccination

Vaccination should not be considered as an emergency measure in case of a threat of infection, since immunity to the disease is formed within a week after vaccination. Therefore, vaccination must be done in advance. If your profession is related to working with people, your risk of getting sick is higher. The World Health Organization also recommends vaccination against influenza to those population groups for which influenza is the most dangerous (predisposed to ARVI, suffering from chronic diseases of the heart, lungs, kidneys, liver, endocrine and nervous systems, children attending children's institutions, etc. ).

Each year, the composition of the flu shot changes, following the variability of the virus itself. There is a difficulty in predicting which strain of the virus will cause an epidemic in a given year. With a successful prognosis, the effectiveness of vaccination is high. If an accurate prediction could not be made, then the vaccine still reduces the body's susceptibility to the virus, as it contains some of its common components. However, it is impossible to guarantee that a person who has been vaccinated will not get sick.

The "Family Doctor" uses the most effective and safe vaccines for influenza vaccination. Vaccination is preceded by a consultation with a doctor, designed to minimize the risk of possible complications. In some cases, vaccination cannot be done (with intolerance to the components of the vaccine, with acute or chronic diseases in the acute stage, etc.)