Feverish form of tick-borne encephalitis. Characteristics and symptoms of tick-borne encephalitis

Tick-borne encephalitis Is an acute viral disease nervous system... The causative agent of the disease is a specific virus that more often enters the human body when bitten by a tick. Infection is possible when eating raw milk from sick animals. The disease manifests itself as general infectious symptoms and damage to the nervous system. Sometimes it is so severe that it can be fatal. People living in areas with a high prevalence of the disease are subject to preventive vaccination. Vaccination reliably protects against disease. From this article you will learn how tick-borne encephalitis proceeds, how it manifests itself and how to prevent the disease.

Tick-borne encephalitis is sometimes called differently - spring-summer, taiga, Siberian, Russian. Synonyms arose due to the characteristics of the disease. Spring-summer, because the peak incidence occurs during the warm season when ticks are most active. Taiga, because the natural focus of the disease is mainly in the taiga. Siberian - due to the distribution zone, and Russian - due to the detection mainly on the territory of Russia and the description of a large number of virus strains by Russian scientists.

Tick-borne encephalitis causes

The disease is caused by a virus belonging to the arbovirus group. The prefix "arbo" means transmission by arthropods. The tick-borne encephalitis virus reservoir is ixodid ticks that live in the forests and forest-steppe of Eurasia. The virus among ticks is transmitted from generation to generation. And, although only 0.5-5% of all ticks are infected with the virus, this is enough for the periodic occurrence of epidemics. In the spring-summer period, there is an increased activity of ticks associated with their development cycle. At this time, they actively attack people and animals.

The virus gets to a person through the bite of an ixodid tick. Moreover, the sucking of a tick, even for a short period of time, is dangerous for the development of encephalitis, since the tick saliva containing the pathogen immediately enters the wound. Of course, there is a direct relationship between the amount of the pathogen that has entered the blood of a person and the severity of the disease that has developed. Duration incubation period (the time from the entry of the pathogen into the body until the first symptoms appear) also directly depends on the amount of the virus.

The second way of getting infected is by eating raw milk or foods made from thermally unprocessed milk (such as cheese). More often, the culprit of the disease is the use of goat milk, less often - cows.

Another rare way of infection is the following: a tick is crushed by a person before it sucks, but from contaminated hands the virus gets onto the mucous membrane of the oral cavity if personal hygiene is not followed.

After entering the body, the virus multiplies at the site of entry: in the skin, in the mucous membrane of the gastrointestinal tract. Then the virus enters the bloodstream and spreads throughout the body. The favorite site of the virus is the nervous system.

Several types of virus have been identified that have a certain territorial attachment. In the European part of Russia, there is a virus that causes less severe forms of the disease. The closer to the Far East, the worse the prognosis for recovery, and the more often deaths occur.

The incubation period lasts from 2 to 35 days. In case of infection due to the consumption of infected milk, it is 4-7 days. You should know that a patient with tick-borne encephalitis is not dangerous to others, since it is not contagious.

Tick-borne encephalitis begins acutely. At first, general infectious signs appear: the body temperature rises to 38-40 ° C, chills occur, general malaise, a diffuse headache, aching and pulling pains in muscles, weakness, sleep disturbance. Along with this, there may be abdominal pain, sore throat, nausea and vomiting, redness of the mucous membrane of the eyes and throat. IN further illness can proceed in different ways. In this regard, several clinical forms of tick-borne encephalitis are distinguished.

Clinical forms of tick-borne encephalitis

Currently 7 forms are described:

• feverish;
• meningeal;
• meningoencephalitic;
• polyencephalytic;
• poliomyelitis;
• polioencephalomyelitis;
• polyradiculoneuritic.

Febrile form characterized by the absence of signs of damage to the nervous system. The disease proceeds like a common cold. That is, the rise in temperature lasts 5-7 days, accompanied by general intoxication and general infectious signs. Then comes an independent recovery. No changes in the cerebrospinal fluid (as in other forms of tick-borne encephalitis) are found. If the tick bite was not recorded, then usually there is no suspicion of tick-borne encephalitis.

Meningeal form, perhaps, is one of the most common. At the same time, patients complain of severe headache, intolerance to bright light and loud sounds, nausea and vomiting, pain in the eyes. Against the background of an increase in temperature, meningeal signs appear: tension in the muscles of the neck, symptoms of Kernig and Brudzinsky. Possible impairment of consciousness by the type of stunning, lethargy. Sometimes there may be motor agitation, hallucinations and delusions. Fever lasts up to two weeks. When carried out in the cerebrospinal fluid, an increase in the content of lymphocytes, a slight increase in protein are found. The changes in the cerebrospinal fluid last longer than clinical symptoms, that is, the state of health may improve, but the tests will still be bad. This form usually ends with a full recovery after 2-3 weeks. Often leaves behind a long-term asthenic syndrome, characterized by increased fatigue and fatigue, sleep disturbance, emotional disorders, poor exercise tolerance.

Meningoencephalitic form characterized by the appearance of not only meningeal signs, as in the previous form, but also symptoms of damage to the brain substance. The latter are manifested by muscle weakness in the limbs (paresis), involuntary movements in them (from slight twitching to pronounced contractions in amplitude). Contraction violation possible facial muscles persons associated with damage to the nucleus facial nerve in the brain. In this case, the eye does not close on one half of the face, food flows out of the mouth, the face looks distorted. Among other cranial nerves, the glossopharyngeal, vagus, accessory, and sublingual nerves are more often affected. This is manifested by impaired speech, nasal voice, choking when eating (food gets into airways), violation of tongue movements, weakness of the trapezius muscles. Possible violation of the rhythm of breathing and heartbeat due to damage vagus nerve or centers of respiration and cardiac activity in the brain. Often with this form, epileptic seizures and disturbances of consciousness of varying severity occur, up to coma. In the cerebrospinal fluid, an increase in the content of lymphocytes and protein is detected. This is a severe form of tick-borne encephalitis, in which the development of cerebral edema with dislocation of the trunk and impairment of vital functions is possible, as a result of which the patient may die. After this form of tick-borne encephalitis, paresis, persistent speech disorders, swallowing are often left, which cause disability.

Polyencephalytic form characterized by the onset of symptoms of cranial nerve damage on the 3-5th day of an increase in body temperature. The bulbar group is most often affected: glossopharyngeal, vagus, hypoglossal nerves. This is manifested by a violation of swallowing, speech, immobility of the tongue. They suffer somewhat less often and trigeminal nerves, which causes symptoms such as sharp pain in the face and deformation. At the same time, it is impossible to wrinkle your forehead, close your eyes, your mouth twists to one side, food pours out of your mouth. Lacrimation is possible due to constant irritation of the mucous membrane of the eye (because it does not close completely even during sleep). Even less often, defeat develops oculomotor nerve, which is manifested by strabismus, movement disorder eyeballs... This form of tick-borne encephalitis can also be accompanied by a violation of the activity of the respiratory and vasomotor centers, which is fraught with life-threatening conditions.

Poliomyelitis formhas such a name in mind of its similarity with. It is observed in approximately 30% of patients. Initially, there is general weakness and lethargy, increased fatigue, against the background of which there are minor muscle twitchings (fasciculations and fibrillations). These twitches indicate damage to the motor motoneurons of the anterior horns of the spinal cord. And then paralysis develops in the upper limbs, sometimes asymmetric. It can be combined with impaired sensitivity in the affected limbs. Within a few days, muscle weakness invades the muscles of the neck, chest and arms. The following symptoms appear: "head hanging on the chest", "bent hunched posture". All this is accompanied by severe pain, especially in the back of the neck and shoulder girdle. Less common is the development of muscle weakness in the legs. Usually, the severity of paralysis increases for about a week, and after 2-3 weeks an atrophic process develops in the affected muscles (muscles are depleted, "lose weight"). Muscle recovery is almost impossible, muscle weakness remains with the patient for the rest of his life, making it difficult to move and self-care.

Polioencephalomyelitis formcharacterized by symptoms characteristic of the previous two, that is, simultaneous damage to the cranial nerves and neurons of the spinal cord.

Polyradiculoneuritic formmanifested by symptoms of damage to peripheral nerves and roots. The patient develops severe pain along the nerve trunks, impaired sensitivity, paresthesia (feeling of crawling, tingling, burning, and others). Along with these symptoms, ascending paralysis is possible, when muscle weakness occurs in the legs and gradually spreads upward.

A separate form of tick-borne encephalitis is described, characterized by a kind of two-wave course of fever. With this form, in the first wave of temperature rise, only general infectious symptoms appear, reminiscent of a cold. After 3-7 days, the temperature returns to normal, the condition improves. Then comes the "light" period, which lasts 1-2 weeks. There are no symptoms. And then a second wave of fever sets in, along with which a lesion of the nervous system occurs according to one of the options described above.

There are also cases of chronic infection. For some reason, the virus is not completely eliminated from the body. And after a few months or even years "makes itself felt." More often it manifests itself epileptic seizures and progressive muscle wasting, resulting in disability.

The transferred disease leaves behind strong immunity.

Diagnostics

To make a correct diagnosis, the fact of a tick bite in areas endemic for the disease is important. Since specific clinical signs there is no disease, then serological methods play an important role in diagnosis, with the help of which antibodies against tick-borne encephalitis virus are detected in the blood and cerebrospinal fluid. However, these tests become positive from the 2nd week of illness.

I would especially like to note the fact that the virus can be found in the tick itself. That is, if you are bitten by a tick, then it must be delivered to medical institution (if possible). When a virus is detected in tick tissues, preventive treatment - the introduction of a specific anti-mite immunoglobulin or the administration of Iodantipyrine according to the scheme.

Treatment and prevention

Treatment is carried out using various means:

• specific anti-tick immunoglobulin or serum of those who have had tick-borne encephalitis;
• antiviral drugs are used: Viferon, Roferon, Cycloferon, Amiksin;
• symptomatic treatment consists in the use of antipyretic, anti-inflammatory, detoxification, dehydration drugs, as well as drugs that improve microcirculation and blood flow in the brain.

Prevention of tick-borne encephalitis can be non-specific and specific. Non-specific measures include the use of agents that repel and destroy insects and ticks (repellents and acaricides), wearing the most closed clothing, a thorough examination of the body after visiting a forest park area, and eating thermally processed milk.

Specific prophylaxis is emergency and planned:

• emergency consists in the use of anti-tick immunoglobulin after a tick bite. It is carried out only in the first three days after the bite, later it is no longer effective;
• it is possible to take Yodantipyrin within 9 days after the bite according to the scheme: 0.3 g 3 r / day for the first 2 days, 0.2 g 3 times a day for the next 2 days and 0.1 g 3 times a day for the last 5 days ;
• planned prevention is vaccination. The course consists of 3 injections: the first two with an interval of a month, the last one - a year after the second. This introduction provides immunity for 3 years. To maintain protection, revaccination is required once every 3 years.

Tick-borne encephalitis is a viral infection that occurs initially under the guise of an ordinary colds.
It can pass unnoticed by the patient, and can cause severe damage to the nervous system. The results of the transferred tick-borne encephalitis can also vary from complete recovery to permanent disability. It is impossible to get sick with tick-borne encephalitis again, since the transferred infection leaves a persistent lifelong immunity. In areas endemic for this disease, it is possible to carry out specific prophylaxis, vaccination, which reliably protects against tick-borne encephalitis.

Survey TV, a story on the topic "Tick-borne encephalitis":

Useful video about tick-borne encephalitis

viral infection, of natural origin, appearing during spring, summer and early autumn.

The infection occurs during absorption into the skin and suction of blood from the human body (in the first minutes of suction) by a tick affected by the encephalitis virus.

Studies have shown that the duration of the suction of blood from the human body is on the order of several days, and the body weight of the insect, at the same time, increases many times.

Infection with this infection is also possible by ingesting infectious raw milk or by-products made from an infected ingredient (milk).

The presence of the virus in the tissues of the human brain is determined, a few days after the bite (data from a clinical study), and is maximally observed on day 4.

The incubation period of tick-borne encephalitis depends on the method of infection (with a bite 7-20 days, through food 4-7 days). Not everyone who is bitten by a tick gets sick. It all depends on the body's immune system.

How and when does the disease occur

Infection with tick-borne encephalitis affects people whose activities are carried out in forest areas (timber industry workers, geologists, tourists, hunters), less, but still at risk, and city dwellers visiting recreation parks with forest plantations, dachas (garden and vegetable garden plots).

For infection, branches of plants brought into the house from the forest, parks, summer cottages may also be suitable.

Ticks are considered carriers.living in forest spaces, and affected by infection. Clinical studies carried out on animals have shown that the affected animal (by a tick bite) experienced malaise, lethargy.

And after about 5 days, the virus damaged all organ tissues. The accumulation of the virus was observed in the genital tract, intestines and salivary glands.

Pathogenesis

Differs in two reproductions:

1. The virus, when bitten by a tick, enters the blood cells. In them (inside) its development takes place, and when fully formed, it moves to the cell membrane, subsequently leaving it.
2. Lymph nodes, cells of the liver, spleen are affected, and then, the virus enters the motor neurons of the spinal cord, the pia mater and the cells of the cerebellum.

Types of disease

In modern medical literature, domestic authors, depending on the period and form of the course of the disease, and the number of deaths, it is permissible to divide infection viruses into the following types as danger:

• west;
• siberian;
• far Eastern.

Common signs of the disease

After a hike in an area dominated by a large number of deciduous trees and vegetation, the first signs of tick-borne encephalitis can be suspected when appearance:

Signs of tick-borne encephalitis in people:

• the appearance of weakness in the limbs;
• the appearance of seizures, numbness of the facial joints and neck;
• paralysis of individual parts of the muscles, then completely of the limbs.

The development of the disease is acute with distinctive signs:

• chills and fever lasting 2 to 10 days;
• general malaise of the patient;
• clouding of consciousness;
• different stages of deafness (different degrees).

As the body becomes infected, such symptoms of tick-borne encephalitis:

• severe headaches, accompanied by loss of consciousness, vomiting;
• damage to the mucous membranes of the body ( oral cavity, eye (conjunctivitis develops));
• development coma with loss of time interval and space.

Moreover, in patients observed:

• malfunctions of the cardiac system, cardiovascular failure and arrhythmia appear;
• malfunctions digestive tract, there is a stool retention, with an internal check of organs can be detected;
• an increase in the size of the liver and spleen.

At the same time, throughout the entire development of the infectious period, the patient has an elevated temperature within 40 degrees.

Despite the severe consequences of this disease, most often, the disease is mild, characterized by a slight fever.

Clinical forms of the disease

Experts distinguish several forms of the disease, depending on the severity of it symptoms:

• feverish;
• meningeal;
• meningoencephalitic;
• poliomyelitis;
• polyradiculoneuritic.

Symptoms depending on the form of the disease

The symptoms of infection are characterized by appearance:

• fever;
• intoxication of the brain (damage to its gray matter), subsequently the development of encephalitis;
• damage to the brain and spinal cord, in particular its membranes, as a consequence of the development of diseases meningitis and meningoencephalitis.

The listed diseases are dangerous because, if they are not treated in time, they lead to complications of a neurological and psychiatric nature, as well as to death (death).

Each form of the disease has its own specific first symptoms of tick-borne encephalitis.

Febrile form

It is caused by a mild course of the disease and a quick cure. Signs of infection are:

• headache, weakness, nausea;
• the presence of fever, which ranges from 3-5 days.

Meningeal form

A common form of the disease. The febrile state proceeds with intensified symptoms (listed below in the text) and ranges from 7 to 14 days:

• headache (at the slightest movement), dizziness;
• nausea with single or repeated vomiting;
• pain in the eyes;
• lethargy and lethargy are observed.

Meningoencephalitic form

It is often found in the Far Eastern part of the country. It leaks and has a severe form. In patients observed:

• delusional state with hallucinations;
• loss of orientation in time and place.

Missed treatment for this type of disease, leads to:

• brain damage by reference to the body's respiratory reflexes;
• numbness of the facial muscles and muscles of the tongue;
• epileptic seizures (possible);
• stomach bleeding with bloody vomiting (in rare cases).

How does it differ from the disease in adults. Special symptoms and methods of treatment of pathology in infants.

Severe and severe disease alcoholic polyneuropathy, the treatment of which must be started in a timely manner, otherwise.

Poliomyelitis form

It is observed in a third of patients. It begins with a general lethargy of the whole organism, which is observed within 1-2 days. Accompanied by:

• weakness in the limbs, which can subsequently lead to numbness;
• pain in the neck is characteristic.

Subsequently, with rapid, growing disorders of the motor functions of the body. The result is muscle atrophy.

Polyradiculoneuritic form

The nervous system of the patient is damaged. Paralysis develops, starting in the legs and spreading, subsequently, to the entire trunk, covering the arms of the infected person.

Diagnostics

It is carried out by methods used in medical literature and reference books titles:

Encephalitis as a disease occurs more often in children than in adults, which occurs against the background of infectious diseases, can occur as a complication after vaccinations.

The main symptoms and signs of tick-borne encephalitis in children include:

• the first sign of tick-borne encephalitis is a headache, expressed by an increase in body temperature;
• sleep disorders;
• disorders of the eyeball;
• disorders of the vestibular apparatus.

Treatment of the disease

There is no definite treatment for tick-borne encephalitis in humans in practice. Applicable drug therapy , in which antiviral drugs are prescribed.

In case of damage to the nervous system, with the development of meningitis or encephalitis, the patient should be urgently hospitalized.

In the treatment of this disease, one can distinguish two ways:

• treating tick-borne encephalitis on your own;
• specialist help.

Self-help

Carried out through traditional medicine.

If a tick is found on the body (it looks like a bulge of a dark color, with a substance sticking out from under the skin (the back of the insect's body)), traditional healers recommend dropping a drop on it vegetable oil or any alcohol, and leave for 15-20 minutes.

Under the legs sticking out above the skin of a person, bring a loop-shaped thread, and try to pull it out with smooth, slow, swinging movements. The thread can be replaced with tweezers.

The extracted tick must be placed in any container and taken to a medical clinic to determine whether or not there is an infection in it.

Desirable after removing the insect from the skin, contact a specialist in the same hospital to undergo tests for the presence of infection in your body. Infectionists recommend, even if no infection is detected, to be seen by a doctor during the incubation period.

When the appearance elevated temperature, skin rash, itching, urgent consultation with a specialist is needed.

Specialist help

If, nevertheless, due to a tick bite, an attempt to extract an insect was not crowned with a positive result, or there was a fear of doing the wrong thing action, you need the help of a specialist.

In the hospital, the tick will be removed from the patient's skin, and the patient will receive an injection, intramuscularly, against the development of the disease.

Immunoglobulin is an expensive drug, due to the content of antibodies obtained from donated bloodpreviously vaccinated against tick-borne encephalitis. Besides of this medicine, there are a number of others antiviral drugs, which can be prescribed by a doctor, for prophylactic and therapeutic purposes.

• drug therapy;
• bed rest;
• rational diet.

Forecast

Data are based on 100 people - 100%:

1. Out of a hundred infected patients, complications (neurological and psychiatric) develop in 10-20 people.
2. The lethal outcome occurs for the European type: 1-2 people, for the Far Eastern type: 20-25 people. As a rule, death occurs after the appearance neurological symptoms for 5-7 days.

Preventive measures

1. The preparatory process is carried out in two stages. The first in the autumn, the second in the winter.
2. In case of sudden (extreme) cases, also in two stages, with intervals of two weeks. Immunity as shown clinical researches, develops 14-20 days after vaccination. After 9-12 months, 3 injections should be given.

Everyone, in order to prevent (prevention), needs remember:

Today, tick-borne encephalitis is not incurable and, if detected early, does not cause significant damage to the body.

The key in this case is precisely timely detection of a ticka, therefore, you should especially carefully examine the surface of the skin (especially in children) after visiting the forest.

It should also be remembered that tick-borne encephalitis is not transmitted from one patient to another, it is not dangerous, like a viral disease, to others.

Video: What to do if you have had tick-borne encephalitis

The neurologist talks about what to do next if you are bitten by a tick and the patient has had tick-borne encephalitis. Highly helpful advice the doctors.

Tick-borne encephalitis is a classic flavovirus natural focal infectious disease characterized by a predominant lesion of the central nervous system, severe course and disability. Distinctive feature is polymorphism of clinical manifestations and the development of persistent neurological complications.

In the early 1930s, in a number of places in the Far East, doctors discovered severe acute illnesses, which often ended in death. Local health professionals have classified this completely unexplored neuroinfection as "toxic flu." In 1937, during an expedition under the leadership of Professor Zilber, a virus unknown to science was discovered, its strains were isolated, the disease vector, the ixodid tick, was established, the clinic and pathomorphology were studied. The new disease is called spring-summer epidemic encephalitis.

How can you get infected

A person becomes infected with the tick-borne encephalitis virus during bloodsucking with viral mites. One tick may contain an excess dose of the pathogen - up to 1000 viral particles. The ingestion of one millionth of the viral pool into the blood is enough for the development of the infectious process. The disease is also observed in people who removed only crawling ticks.

It has been proven that tick-borne encephalitis is transmitted when working with biological material in laboratory conditions, through blood transfusions, organ and stem cell transplants, while breastfeeding, transplacental infection of the fetus is possible.

Important! A sick person as a source of infection for others is not dangerous.

There is also an alimentary route of infection, such as eating raw milk from infected goats. In milk at refrigerator temperature, the virus persists for 2 weeks, in sour cream and butter, it is detected for up to 2 months. But in comparison with vector-borne transmission of infection, the proportion of this pathway is insignificant.

Tick-borne encephalitis symptoms

The latent period of the disease, when it does not manifest itself in any way, ranges from 2 to 35 days, on average 7-14 days. After the incubation period, the first signs of encephalitis after a tick bite begin acutely. The severity of symptoms depends on the genotype of the virus and the severity of the disease. The main clinical manifestation is a general infectious syndrome, which is expressed by raising the temperature to high numbers (39-40 ° C), headache of varying intensity, soreness when moving the eyeballs, atrophies, myalgia in the cervico-shoulder and lumbar region, legs, joints.

Loss of appetite, nausea, single or repeated vomiting, dizziness are observed. Characterized by lethargy, drowsiness, or, conversely, slight agitation, flushing of the face, neck, upper third of the body. After 3-5 days, damage to the nervous system develops, which is expressed by a disorder of sensitivity, motor disorders, up to paralysis.

What happens to the body during infection

After the virus enters the body, it begins to multiply intensively in the vessels of the skin and regional lymph nodes at the site of tick suction or in the tissues of the digestive tract during the alimentary route of infection. This stage corresponds to the incubation period, there are no visible symptoms of tick-borne encephalitis in humans.

Further, the viremia phase develops, when the pathogen spreads through the capillary network of blood and lymphatic vessels. It multiplies in blood leukocytes, liver, spleen and kidney cells. Flu-like symptoms appear.

96 hours after infection, the virus is found in high concentrations in all internal organs and tissues of the immune system. This is the visceral phase of pathogenesis. Further, the pathogen enters the central nervous system, affecting the gray matter. It multiplies in the nerve cells of the brain and spinal cord. As a result, polioencephalitis and poliomyelitis develop.

After the transferred tick-borne viral encephalitis, persistent, lifelong immunity remains. Virus-neutralizing antibodies are observed in the blood for a long time.

Varieties of the course of the disease

The clinical manifestations of encephalitis depend on the virulence of the virus and the body's defenses. If the virus fails to overcome the blood-brain barrier, it does not enter the brain, and then the pathology proceeds quite easily, with erased symptoms of the disease. In such cases, pathology can only be determined with the help of tests. During the illness, a person feels healthy, but at the same time he develops antibodies to the tick-borne encephalitis virus and strong immunity. Antibodies are also often found in people living in endemic areas who do not have encephalitis, indicating contact with the virus.

In some patients, the virus crosses the blood-brain barrier, which leads to damage to the central nervous system. Clinically, the disease develops in an acute cyclical form with recovery, but it can transform into a chronic infection. Severe complications acute form sometimes come to the end with paralysis and death.

Chronic infection with brain damage is lifelong, in many cases it occurs in childhood and young age and is formed after acute illness in terms from several months to 3-5 years. More frequent chronicity of the process in puberty is due to hormonal changes in the body at this age. The photo below shows chronic stage tick-borne encephalitis in a patient with atrophy of the muscles of the shoulder girdle.

There are 5 main clinical forms of tick-borne encephalitis, each of which proceeds in a different way. These include febrile, meningeal, meningoencephalitic, polymyelitic, polyradiculoneurotic forms.

How is the treatment

On the question of whether tick-borne encephalitis can be treated, the answer is ambiguous. Despite the fact that the etiology, pathogenesis, clinical picture of the disease has been studied well enough, the issue of therapy requires a search for new methods and approaches.

Treatment is carried out in a hospital setting. At the stage of primary pre-medical health care medication is aimed at lowering body temperature and preventing the development of complications. In the future, the choice of tactics depends on the clinical form, the severity of the disease, the patient's age, the presence and nature of complications, the availability and possibility of performing treatment.

Medicinal treatment of tick-borne encephalitis consists of etiotropic and pathogenetic therapy. A common method of prevention and treatment is the use of human serum anti-tick immunoglobulin according to the standard regimen.

Pathogenetic therapy:

• detoxification therapy (parenteral administration of isotonic solutions);
• dehydration therapy to prevent cerebral edema;
• non-steroidal anti-inflammatory drugs with severe pain syndrome, an increase in body temperature above 38.5 ° C;
• glucocorticosteroids;
• antihistamines;
• antibacterial agents for severe forms of tick-borne encephalitis in humans, complicated by signs of bacterial infection;
• antifungal drugs according to indications.

Besides drug treatment tick-borne encephalitis symptoms should be observed and strict bed rest up to 5-7 days normal temperature and until the symptoms of intoxication disappear. An individual diet is prescribed depending on the symptoms and severity of the disease.

All persons who have overcome tick-borne encephalitis, regardless of the clinical form, are subject to dispensary observation for 1-3 years.

What can tick-borne encephalitis lead to?

The acute period of infection does not always end with recovery. Very often, those who have recovered note certain symptoms of damage to the central nervous system. Outcomes in the form of asthenia, psychovegetative hypertensive-hydrocephalic syndromes are considered relatively favorable. Residual effects of tick-borne encephalitis are manifested mainly in the form of spastic and flaccid paresis of varying severity. In some cases, the consequences remain in the form mental disorders, epileptic seizures.

Often transferred tick-borne encephalitis becomes the cause of disability. In the event of gross pathological changes incompatible with life, an extremely unfavorable outcome occurs - death.

Statistics

Favorable climatic conditions in Russian Federation promote the activation of ticks transmitting various infectious diseases... Several thousand cases are registered annually, and there are cases with a fatal outcome. According to the statistics of 2016 in Russia, out of 467 thousand people who applied for a tick bite, 2035 cases of tick-borne encephalitis were recorded, including 513 cases of infection among children.

How not to get sick with tick-borne encephalitis

In order to prevent the development of tick-borne encephalitis in medical organizations, preventive vaccinations travelers traveling to regions endemic for this disease. The entire course of vaccinations should be completed 2 weeks before departure to an unfavorable territory. Within four days after the removal of the tick, according to indications, seroprophylaxis is carried out - the introduction of human immunoglobulin against tick-borne encephalitis.

Tick-borne encephalitis with symptoms of damage to cerebral structures is called an acute viral pathology that occurs in people after a tick bite. The peak incidence, as a rule, falls on the warm season - May-August, when the population actively visits the forest. Without appropriate antiviral treatment, death can occur or a person becomes deeply disabled. However, in the case of the introduction of a specific vaccine, the body develops a special protection against encephalitis. Therefore, doctors urge people to be sure to vaccinate against encephalitis ticks.

Since the viral particles after the tick bite has occurred, it takes a certain time to activate in the human bloodstream, at this moment no special signs of tick-borne encephalitis are observed. Sometimes there may be a slight malaise in the form of chills, weakness, dizziness.

Subsequently, the debut of encephalitis is acute. Typical symptoms after a tick bite are:

• intense discomfort in the joints, sacrum area;
• cephalalgia - soreness in the head, especially in the area of \u200b\u200bthe eyeballs;
• nausea and even indomitable vomiting - often do not bring relief from well-being;
• hyperthermia - with an increase in body temperature up to 39 degrees;
• disturbances of consciousness - lethargy, or deafness, drowsiness.

After the tick-borne virus has moved into the medulla with its inflammation, the signs of encephalitis will be bright and the correct diagnosis does not cause difficulties for specialists:

• increased sensitivity to sunlight;
• violations of superficial as well as deep sensitivity;
• malfunctions in the muscular system - activity is lost first of the facial muscles, and then in the limbs;
• convulsive involuntary contractions, epileptic seizures are possible;
• growing weakness - the inability to raise your head from the pillow, take care of yourself, and eat on your own.

If the brain stem is involved in the pathological process, symptoms of cardiovascular / respiratory failure will appear simultaneously with persistent hyperthermic syndrome. A similar form of tick-borne encephalitis often ends in coma and death.

Incubation period

By itself, a tick does not pose a danger to humans - its own protection of integumentary tissues is able to cope with such external aggression. With a weakened immunity and a large dose of a tick-borne virus that entered the bloodstream after a tick bite, encephalitis can form literally in a matter of hours.

Experts do not indicate the exact timing of the incubation period. Traditionally, it is customary to focus on the fact that in most cases, signs of damage to nerve structures appear by 8-21 days from the moment of infection. Less often, a fulminant form is observed - encephalitis proceeds in 1-3 days, or a prolonged variant - tick infestation makes itself felt by the end of the month after the virus enters the body.

On average, the appearance of signs of a tick bite in humans is 1.5–3 weeks, since it all depends on the variant of encephalitis. For example, the most common, meningeal, variant is characterized by rapid development clinical picture inflammation of the lining of the brain. Whereas with polyradiculoneurotic encephalitis, the incubation period can be 2.5–3 weeks.

Causes

In 2/3 of cases, infection with human tick-borne encephalitis is, of course, based on the bite of a carrier tick. Damage to cerebral structures viral infection occurs after the injection of particles dangerous for the nervous system into the bloodstream.

The characteristic of the tick-borne virus is its low resistance to high temperatures and UV rays. Therefore, it practically cannot exist outside the host's organism. Meanwhile, in cold weather, viral particles in the external environment persist for a long time.

Tick-borne encephalitis develops not only when a person is bitten by insects, but also from taking milk from an infected cow - an alimentary route of infection. Less commonly, the virus enters through scratched skin, which contains tick feces or particles of its damaged body.

Arobavirus enters the human brain tissue exclusively from the outside in the following ways:

• tick bite;
• alimentary - through products from infected animals;
• fecal-oral through dirty hands, on which mite waste products are present;
• through microtraumas on the integumentary tissues - the virus is introduced by scratching the skin on which the tick was present.

Encephalitis can be avoided with careful adherence to public safety rules.

Diagnostics

The correct collection of anamnesis contributes to the identification of the disease after a tick bite - the doctor asks a person whether he has recently visited the forest, whether he has traveled to those regions where an unfavorable epidemic situation for tick-borne encephalitis. Then the specialist examines the integumentary tissues - identifying wounds or inflammatory areas of the skin that may indicate a pre-existing bite. It is especially true if encephalitis in children is suspected. After all, a baby can not always answer questions of interest to a specialist.

Tests for tick-borne encephalitis will confirm the preliminary diagnosis:

• examination of a directly infected tick;
• PCR diagnostics - detection of virus particles in the cerebrospinal fluid, as well as in the blood;
• Serological concentration of the titer of antibodies to the virus - its decrease / increase in two sera, which were taken with a break of two weeks.

Additional instrumental research to establish encephalitis in a person, the doctor may recommend electroencephalography and computed tomography brain. After comparing all the information from the diagnostic procedures, the specialist gives his opinion and selects the optimal therapy.

Therapeutic tactics

For effective fight with signs of tick-borne encephalitis, treatment should be started on the day of the bite and in full. Antiencephalitis immunoglobulin therapy has proven itself well. Benefits leading inactivated vaccine with ribonucleic acid, if the procedure was carried out directly 1.5–3 hours of presumptive encephalitis after a tick bite.

For complex treatment tick-borne encephalitis, a person is necessarily placed in a hospital, where he is immediately injected with immunoglobulin - strictly under the supervision of a doctor. It is with his help that your own the immune system the infected person is able to quickly cope with the insidious neurotropic virus.

In the future, after a tick bite, the treatment adheres to the principles of symptomatic therapy:

• antipyretic drugs - antipyretics;
• detoxifying solutions - accelerating the elimination of toxins from tissues;
• vitamins - to raise immunity, improve the activity of the nervous system;
• medicines that correct the water-salt balance in the body;
• antiemetics;
• analgesics.

More severe manifestations of tick-borne encephalitis in children. Therefore, their doctors observe longer, they are in no hurry to discharge them from the hospital under outpatient follow-up neuropathologists. In the future, the dispensary control of babies should be at least three years old.

Prevention

As such, the specific prophylaxis of tick-borne encephalitis is three times the vaccination. After all, the body then produces anti-mite antibodies. IN National calendar universal immunization of the population does not provide for such a procedure. However, each person on their own may see a doctor for a tick-borne vaccination.

Non-specific disease prevention:

• stop eating unpasteurized foods, especially dairy products;
• when traveling to the forest, wear clothes that will completely cover all parts of the body;
• timely contact medical institutionif a case of a tick bite has been identified;
• be sure to use repellents;
• carefully observe the rules of personal safety during the season of tick activity - take a hygienic shower and inspect clothes and clothes after each trip to the country, to the country.

Great attention is paid to the preservation of health of the population by medical workers. However, each person should know and be able to apply the rules for the prevention of tick bites.

Consequences and complications

Since human infection does not occur in all cases of human collision with forest insects, the percentage of complications of tick-borne encephalitis among bitten individuals is low. The prognosis largely depends on the type of pathology and the initial state of the patient's health.

The main consequences of an encephalitis tick bite in humans are:

• persistent headaches;
• tendency to epilepsy;
• various sensitivity disorders;
• decreased memory and intellectual capabilities.

In severe cases of the disease, encephalitis tick in humans provokes complications such as paralysis of the muscles of the hands and lower limbs, a sharp weakening of brain activity, chronic focal disorders. People become deeply disabled, and it is not possible to return them to society.

The prognosis is more favorable for a febrile form of encephalitis - recovery reaches 2/3 of cases. Whereas with meningoencephalitis, complications are formed more often and they are more severe.

Tick-borne encephalitis is an acute viral disease that mainly affects nerve cells in the human body. These can be structures of the brain, peripheral innervation or radicular nerve endings in the spinal cord.

The main source of infection is the ixodid taiga tick. For the reproduction of these insects, animal or human blood is needed. Spring-summer seasonality is associated with the biology of tick vectors. The virus, entering the tick's stomach with the blood of infected animals, penetrates into all organs of the tick and is then transferred to other animals, and is also transmitted to the offspring of the tick (transovarial transmission of the virus).

The penetration of the virus into the milk of farm animals (goats) has been proven, therefore alimentary ways of infection of people through goats and cows are possible. Alimentary “goat” endemic foci of encephalitis have been established in various regions of the former Soviet Union.

Where is tick-borne encephalitis common?

Currently, the disease with tick-borne encephalitis is recorded almost throughout the territory of Russia (about 50 territories of the constituent entities of the Russian Federation are registered), where ticks are its main carriers. The most disadvantaged regions in terms of morbidity are: the Ural, West Siberian, East Siberian and Far East regions, and from the adjacent to the Moscow region - Tver and Yaroslavl.

Incubation period

The time from the moment of infection until the first symptoms of tick-borne encephalitis appear is approximately 10-14 days. The incubation period can be lengthened in people who received vaccinations against tick-borne encephalitis in childhood.

There are also several stages of the disease:

1. Lightning fast. With her initial symptoms appear on the first day. In the absence of adequate treatment, the sick person quickly falls into a coma and dies from paralysis of the central nervous system.
2. Protracted. In this case, the duration of the incubation period can be about a month, sometimes even slightly longer.

The first signs of the disease (what you should pay attention to): usually a week after resting in nature, a person suddenly develops a headache, nausea, vomiting that does not bring relief, an increase in body temperature to 39-40 °, severe weakness. Then join brain symptoms: paralysis of the limbs, strabismus, pain along the nerve endings, convulsions, loss of consciousness.

Classification

The clinical classification of tick-borne encephalitis is based on determining the form, severity and nature of the course of the disease. Tick-borne encephalitis forms:

• inapparent (subclinical):
• feverish;
• meningeal;
• meningoencephalitic;
• poliomyelitis;
• polyradiculoneuritic.

According to the nature of the course, acute, two-wave and chronic (progressive) course are distinguished.

Tick-borne encephalitis symptoms

After a tick bite, the virus multiplies in tissues, enters the lymph nodes and blood. When the virus multiplies and when it enters the bloodstream, flu-like symptoms form. The virus crosses the blood-brain barrier and affects brain tissue - neurological symptoms occur.

But the brightness of clinical manifestations, the speed of their growth and specificity always depend on what subtype of the disease and on the location of the virus.

1. European - it is characterized by 2 phases. The first is similar in manifestations to the flu and lasts about a week. The second phase is characterized by lesions of the nervous system of varying degrees: from meningitis light form to severe encephalitis.
2. Far Eastern - usually begins with a febrile state, is acute. Other symptoms can build up just as quickly, leading to paralysis and coma. The lethal outcome can be within 6-7 days.

Despite the wide variety of symptoms and manifestations of the course of the disease, there are 4 main clinical forms tick-borne encephalitis:

1. Feverish. Tick-borne encephalitis virus does not affect the central nervous system, only symptoms of fever appear, namely heat, weakness and body aches, loss of appetite, headache and nausea. Fever can last up to 10 days. Cerebrospinal fluid does not change, symptoms of damage to the nervous system are absent. The forecast is the most favorable.
2. Meningeal. After a period of fever, a temporary decrease in temperature occurs, the virus at this time penetrates into the nervous system, and the temperature rises again sharply, signs of neurological disorders appear. Headaches with vomiting, severe photophobia and stiff neck muscles, symptoms of irritation of the membranes of the brain, and changes in cerebrospinal fluid appear.
3. Meningoencephalitic... It is characterized by damage to brain cells, which are characterized by impaired consciousness, mental disorders, convulsions, weakness in the limbs, paralysis.
4. Poliomyelitis... The onset of this form of the disease is manifested by severe fatigue, general weakness... Numbness occurs in the body, after which flaccid paralysis of the muscles of the neck and arms, proximal parts appears upper limbs... Hanging head syndrome appears. The increase in movement disorders occurs within a week, after which the affected muscles atrophy occurs. The poliomyelitis form of the course of the disease occurs quite often, in almost 30% of cases. The course is unfavorable, disability is possible.

It is worth noting that different people have different susceptibility to tick-borne encephalitis. When living for a long time in a natural focus, a person may be exposed to repeated suction by ticks with the ingress of small doses of the virus. After that, antibodies are produced in the blood, the accumulation of which contributes to the development of immunity to the virus. If such people become infected, the disease will be mild.

Diagnosis of tick-borne encephalitis

In the case of tick-borne encephalitis, diagnosis is carried out using tomographic studies of the brain, serological and virological studies. Based on all indicators, an accurate diagnosis is established.

Brain damage is determined primarily on the basis of complaints during a neurological examination by a doctor. The presence of inflammation and the nature of brain damage are established, the causes of encephalitis are determined.

How to treat tick-borne encephalitis

There is no specific treatment for tick-borne encephalitis. If symptoms appear that indicate damage to the central nervous system (meningitis, encephalitis), the patient should be immediately hospitalized for maintenance therapy. As symptomatic treatment often resort to corticosteroids. In severe cases, it becomes necessary to intubate the trachea, followed by mechanical ventilation.

Etiotropic therapy consists in the appointment of a homologous gamma globulin titrated against the tick-borne encephalitis virus. Thanks to this drug, you can observe a clear therapeutic effect, especially when it comes to a severe or moderate course of the disease. Gamma globulin is administered in 6 ml intramuscularly every day for three days. Healing effect observed 13-24 hours after drug administration - the patient's body temperature returns to normal, improves general state, meningeal phenomena and headaches decrease, may even disappear completely. IN last years for the treatment of tick-borne encephalitis, serum immunoglobulin and homologous polyglobulin are used, which are obtained from the blood plasma of donors living in natural foci of tick-borne encephalitis.

Only 2-3 weeks after intensive treatment, subject to normalization of body functions and stabilization of the condition, the patient must be discharged from the hospital. Hard work, mental strain are contraindicated. Regular walks are recommended, and it is advisable to use tick repellents. A doctor's visit is compulsory for two years.

Tick-borne encephalitis and its prevention

As a specific prevention of tick-borne encephalitis, vaccination is used, which is the most reliable preventive measure. All persons living in or leaving endemic areas are subject to compulsory vaccination. The population in endemic areas is about half of the total population of Russia.

In Russia, vaccination is carried out with foreign (FSME, Encepur) or domestic vaccines according to the basic and emergency schemes. The basic scheme (0, 1-3, 9-12 months) is carried out with subsequent revaccination every 3-5 years. To form immunity by the beginning of the epidemic season, the first dose is administered in the fall, the second in the winter. An emergency scheme (two injections with an interval of 14 days) is used for unvaccinated persons who come to endemic foci in the spring and summer. Emergency vaccinated persons are immunized for only one season (immunity develops in 2-3 weeks), after 9-12 months they are given the third injection.

As an emergency prophylaxis during tick sucking, unvaccinated people are injected intramuscularly with immunoglobulin from 1.5 to 3 ml. depending on age. After 10 days, the drug is re-injected in an amount of 6 ml.

Forecast

With tick-borne encephalitis, the prognosis for dysentery depends on the degree of damage to the nervous system. With a febrile form, as a rule, all patients recover completely. With the meningeal form, the prognosis is also favorable, but in some cases persistent complications from the central nervous system in the form of chronic headaches and the development of migraine may occur.

The focal form of tick-borne encephalitis is the most unfavorable prognosis. The mortality rate can be up to 30 people per 100 cases. Complications of this form are the occurrence of persistent paralysis, convulsive syndrome, decreased mental abilities.

Where to get vaccinated against tick-borne encephalitis 2016?

In 2016, in Moscow, in all administrative districts from March to September, vaccination centers operate annually at the bases of polyclinics, medical units, health centers of educational institutions: (in the Western Administrative District - in children's polyclinic No. 119; in polyclinics for adults: No. 209, No. 162 and MSU polyclinic No. 202), as well as the Central Vaccination Center on the basis of polyclinic No. 13 (Trubnaya st., 19, building 1 telephone: 621-94-65).

Where to conduct a laboratory test of ticks?

Tick \u200b\u200btesting for pathogen infection natural focal infections is held at the Federal Budgetary Healthcare Institution "Federal Center for Hygiene and Epidemiology", the Federal State Budgetary Healthcare Institution "Center for Hygiene and Epidemiology in Moscow", and the Federal State Budgetary Institution of Healthcare of the Russian Federation.
When contacting the laboratory, it is necessary to provide information about the date and territory on which the tick sucked (region, region, settlement).