Specific treatment of tick-borne encephalitis. Tick-borne encephalitis - symptoms, prevention and treatment

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

The main source of infection is the ixodid taiga tick. To reproduce these insects, animal or human blood is required. Spring-summer seasonality is associated with the biology of tick vectors. The virus, entering the stomach of a tick with the blood of infected animals, penetrates 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, so nutritional routes of infection of people through goats and cows are possible. Nutritional “goat” endemic foci of encephalitis have been identified in various regions of the former Soviet Union.

Where is tick-borne encephalitis common?

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

Incubation period

The time from the moment of infection to the appearance of the first symptoms of tick-borne encephalitis is approximately 10-14 days. The incubation period may lengthen in people who received vaccinations against tick-borne encephalitis in childhood.

There are also several stages of the disease:

1. Lightning fast. With it, the initial symptoms appear already 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 a little longer.

The first signs of the disease (what you should pay attention to): usually a week after relaxing in nature, a person suddenly develops a headache, nausea, vomiting that does not bring relief, an increase in body temperature to 39-40°, and severe weakness. Then brain symptoms appear: 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 disease. Forms of tick-borne encephalitis:

• inapparent (subclinical):
• febrile;
• meningeal;
• meningoencephalitic;
• polio;
• polyradiculoneuritic.

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

Symptoms of tick-borne encephalitis

After a tick bite, the virus multiplies in tissues and penetrates the lymph nodes and blood. When the virus multiplies and enters the bloodstream, flu-like symptoms form. The virus penetrates the blood-brain barrier and infects brain tissue, causing neurological symptoms.

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

1. European - it is characterized by 2 phases. The first symptoms are similar to the flu and last about a week. The second phase is characterized by damage to the nervous system of varying degrees: from mild meningitis to severe encephalitis.
2. Far Eastern– usually begins with a feverish state and is acute. Other symptoms can increase just as quickly, leading to paralysis and coma. Death can occur within 6-7 days.

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

1. Feverish. The tick-borne encephalitis virus does not affect the central nervous system; only symptoms of fever appear, namely high temperature, weakness and body aches, loss of appetite, headache and nausea. Fever can last up to 10 days. The cerebrospinal fluid does not change, there are no symptoms of damage to the nervous system. The prognosis is most favorable.
2. Meningeal. After a period of fever, a temporary decrease in temperature occurs, at this time the virus penetrates the nervous system, and again the temperature rises sharply, and signs of neurological disorders appear. Headaches with vomiting, severe photophobia and stiffness of the neck muscles, symptoms of irritation of the meninges appear, and there are changes in the cerebrospinal fluid.
3. Meningoencephalitic. It is characterized by damage to brain cells, which are characterized by impaired consciousness, mental disorders, convulsions, weakness in the limbs, and paralysis.
4. Poliomyelitis. The onset of this form of the disease is manifested by severe fatigue and general weakness. Numbness occurs in the body, followed by flaccid paralysis of the muscles of the neck and arms, proximal parts of the upper extremities. “Dangling head” syndrome appears. The increase in motor disorders occurs within a week, after which atrophy of the affected muscles occurs. The polio form 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 outbreak, a person may be exposed to repeated tick bites and small doses of the virus. After this, 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 based on complaints during a neurological examination by a doctor. The presence of inflammation and the nature of brain damage are established, and the causes of encephalitis are determined.

How to treat tick-borne encephalitis

In the case of tick-borne encephalitis, there is no specific treatment. If symptoms indicating damage to the central nervous system (meningitis, encephalitis) occur, the patient should be immediately hospitalized to provide supportive care. Corticosteroids are often used as symptomatic treatment. In severe cases, there is a need for tracheal intubation followed by artificial ventilation.

Etiotropic therapy consists of prescribing homologous gamma globulin titrated against the tick-borne encephalitis virus. Thanks to this drug, a clear therapeutic effect can be observed, especially if we are talking about severe or moderate disease. Gamma globulin is administered 6 ml intramuscularly, every day for three days. The therapeutic effect is observed 13-24 hours after administration of the drug - the patient’s body temperature returns to normal, general condition improves, meningeal symptoms and headaches decrease, and may even disappear completely. In recent years, serum immunoglobulin and homologous polyglobulin, which are obtained from the blood plasma of donors living in natural foci of tick-borne encephalitis, have been used to treat tick-borne encephalitis.

Only 2-3 weeks after intensive treatment, subject to normalization of body functions and stabilization of the patient’s condition, should the patient be discharged from the hospital. Hard work and mental stress are contraindicated. Regular walks are recommended, and it is advisable to use tick repellents. Visiting a doctor is mandatory 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 endemic areas or traveling to them are subject to mandatory vaccination. The population in endemic areas accounts for approximately half of the total population of Russia.

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

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

Forecast

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

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

Where can I get vaccinated against tick-borne encephalitis 2016?

In 2016, in Moscow, in all administrative districts, from March to September, vaccination points operate annually at the bases of clinics, medical units, and health centers of educational institutions: (in the Western Administrative District - in children's clinic No. 119; in clinics for adults: No. 209, No. 162 and Moscow State University Polyclinic No. 202), as well as the Central Vaccination Point based on Polyclinic No. 13 (Trubnaya St., 19, building 1 telephone: 621-94-65).

Where to conduct laboratory testing of ticks?

Research of ticks for infection with pathogens of natural focal infections is carried out at the Federal Budgetary Institution of Health "Federal Center for Hygiene and Epidemiology", Federal State Budgetary Institution "Center for Hygiene and Epidemiology in Moscow", at the Federal State Budgetary Institution Central Research Institute of Epidemiology of Rospotrebnadzor.
When contacting the laboratory, it is necessary to provide information about the date and territory in which the tick suction occurred (region, region, locality).

Tick-borne encephalitis (spring-summer type encephalitis, taiga encephalitis) is a viral infection that affects the central and peripheral nervous system. Severe complications of acute infection can result in paralysis and death.

The main carriers of the encephalitis virus in nature are ixodid ticks, whose habitat is located throughout the forest and forest-steppe temperate climatic zone of the Eurasian continent. Despite the significant number of species of ixodid ticks, only two species are of real epidemiological significance: Ixodes Persulcatus ( taiga tick) in the Asian and in a number of areas of the European part, Ixodes Ricinus ( European wood tick) - in the European part.

Tick-borne encephalitis is characterized by a strict spring-summer seasonality of the onset of the disease, associated with the seasonal activity of vectors. In the range of I. Persulcatus, the disease occurs in spring and the first half of summer (May-June), when the biological activity of this tick species is highest. For ticks of the species I. Ricinus, there is an increase in biological activity twice per season, and in the range of this tick there are 2 peaks of seasonal incidence of tick-borne encephalitis: in spring (May-June) and at the end of summer (August-September).

Infection human infection with the tick-borne encephalitis virus occurs during the blood-sucking of virus-forming ticks. The female tick's blood-sucking continues for many days, and when fully saturated, it increases in weight 80-120 times. Blood sucking by males usually lasts several hours and may go unnoticed. Transmission of the tick-borne encephalitis virus can occur in the first minutes of tick attachment to a person. It is also possible to become infected through the digestive and gastrointestinal tracts by ingesting raw milk from goats and cows infected with tick-borne encephalitis.

Signs of tick-borne encephalitis. The incubation period of tick-borne encephalitis lasts on average 7-14 days with fluctuations from one day to 30 days. Transient weakness in the limbs, neck muscles, numbness of the skin of the face and neck are noted. The disease often begins acutely, with chills and an increase in body temperature to 38-40°C. Fever lasts from 2 to 10 days. General malaise, severe headache, nausea and vomiting, weakness, fatigue, and sleep disturbances appear. In the acute period, hyperemia (overflow of blood vessels of the circulatory system of any organ or area of ​​the body) of the skin of the face, neck and chest, mucous membrane of the oropharynx, injection of the sclera and conjunctiva is noted.

I am worried about pain throughout the body and limbs. Muscle pain is characteristic, especially significant in muscle groups, in which paresis (partial loss of muscle strength) and paralysis usually occur in the future. From the moment the disease begins, clouding of consciousness and stupor may occur, the intensification of which can reach the level of coma. Often, erythema of varying sizes (redness of the skin caused by dilation of the capillaries) appears at the site of tick suction.

If symptoms of tick-borne encephalitis are detected, the patient should be urgently admitted to an infectious diseases hospital for intensive treatment.

Treatment patients with tick-borne encephalitis is carried out according to general principles, regardless of previous preventive vaccinations or the use of specific gamma globulin (a drug containing antibacterial and antiviral antibodies) for preventive purposes.

In the acute period of the disease, even in mild forms, patients should be prescribed bed rest until the symptoms of intoxication disappear. Almost complete restriction of movement, gentle transportation, and minimizing pain stimulation improve the prognosis of the disease. An equally important role in treatment is the rational nutrition of patients. The diet is prescribed taking into account functional disorders of the stomach, intestines, and liver.

Taking into account the vitamin balance observed in a number of patients with tick-borne encephalitis, it is necessary to prescribe vitamins B and C. Ascorbic acid, which stimulates the function of the adrenal glands, and also improves the antitoxic and pigmentary functions of the liver, should be administered in an amount of 300 to 1000 mg per day.

Prevention of tick-borne encephalitis

The most effective protection against tick-borne encephalitis is vaccination. Clinically healthy people are allowed to get vaccinated after examination by a therapist. Vaccination can only be done in institutions licensed for this type of activity.

Modern vaccines contain inactivated (killed) tick-borne encephalitis virus. After the vaccine is administered, the immune system recognizes viral antigens and learns to fight the virus. Trained cells of the immune system begin to produce antibodies (immunoglobulins), which block the development of the virus that has entered the body. To maintain the protective concentration of immunoglobulin for a long time, it is necessary to administer several doses of the vaccine.

The effectiveness of vaccination can be assessed by the concentration of protective antibodies in the blood (IgG to tick-borne encephalitis virus).

Vaccines against tick-borne encephalitis registered in Russia:
- Tick-borne encephalitis vaccine, culture-based, purified, concentrated, inactivated, dry - for children over 4 years of age and adults.
- EnceVir - for children over 3 years of age and adults.
- FSME-IMMUN Inject - from 16 years old.
- FSME-IMMUN Junior - for children from 1 year to 16 years. (Children should be vaccinated during the first year of life if they are at risk of contracting tick-borne encephalitis.)
- Encepur adult - from 12 years old.
- Encepur for children - for children from 1 year to 11 years.

The above vaccines differ in virus strains, antigen dose, degree of purification, and additional components. The principle of action of these vaccines is the same. Imported vaccines are capable of developing immunity to Russian strains of tick-borne encephalitis virus.

Vaccination is carried out after the end of the tick season. In most regions of Russia, vaccination can begin in November. However, in case of urgent need (for example, if you are going to travel to a natural focus of tick-borne encephalitis), the vaccination can be done in the summer. In this case, the protective level of antibodies appears after 21-28 days (depending on the vaccine and vaccination schedule).

Immunity appears two weeks after the second dose, regardless of the type of vaccine and the chosen regimen. The third dose is administered to consolidate the result. Emergency regimens are not intended for protection after a tick bite, but for the fastest possible development of immunity if the timing of standard vaccination has been missed.

Local adverse reactions include: redness, thickening, soreness, swelling at the injection site, urticaria (an allergic rash resembling that of a nettle burn), and enlargement of the lymph nodes close to the injection site. Usual local reactions are observed in 5% of vaccinated people. The duration of these reactions can reach 5 days.

Common post-vaccination reactions include a rash covering large areas of the body, increased body temperature, anxiety, sleep and appetite disturbances, headache, dizziness, short-term loss of consciousness, cyanosis, cold extremities. The frequency of temperature reactions to Russian vaccines does not exceed 7%.

If a tick is attached, it should be removed immediately. It should be borne in mind that the likelihood of contracting tick-borne encephalitis depends on the amount of virus that penetrates during the “bite” of the tick, that is, on the time during which the tick was in the attached state. If you do not have the opportunity to seek help from a medical facility, then you will have to remove the tick yourself.

When removing a tick yourself, you must follow these recommendations:

A strong thread is tied into a knot as close as possible to the tick’s proboscis, and the tick is removed by pulling it up. Sudden movements are not allowed.

If, when removing the tick, its head, which looks like a black dot, comes off, the suction site is wiped with cotton wool or a bandage moistened with alcohol, and then the head is removed with a sterile needle (previously calcined in a fire). Just like an ordinary splinter is removed.

Removing a tick must be done with caution, without squeezing it, since this may squeeze the contents of the tick along with pathogens into the wound. It is important not to tear the tick when removing it - the remaining part in the skin can cause inflammation and suppuration. It is worth considering that when the head of the tick is torn off, the infection process can continue, since a significant concentration of TBE virus is present in the salivary glands and ducts.

There is no basis for some recommendations that for better removal it is recommended to apply ointment dressings to the attached tick or use oil solutions.

After removing the tick, the skin at the site of its attachment is treated with tincture of iodine or alcohol. A bandage is usually not required.

After removing the tick, save it for testing for infection - usually such a test can be done in an infectious diseases hospital. After removing the tick, place it in a small glass bottle with a tight lid and place a cotton swab lightly moistened with water. Cap the bottle and store it in the refrigerator. For microscopic diagnosis, the tick must be delivered to the laboratory alive.

The material was prepared based on information from open sources

Tick-borne encephalitis is an acute viral disease of the nervous system. Its main sources are two types of ixodid ticks - taiga and European forest ticks. The peak incidence of encephalitis occurs in spring (May-June) and late summer and early autumn (August-September).

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 in the warm season, when ticks are most active. The first peak of the disease is recorded in May-June, the second - at the end of summer.

If you are bitten by an encephalitis tick, the virus enters the bloodstream within the first minutes of contact. According to statistics, six ticks out of a hundred are carriers of the virus (at the same time, from 2 to 6% of people bitten can get sick from an infected individual).

The causative agent of tick-borne encephalitis is an RNA virus belonging to the Vlaviviridae family. There are 3 types of virus:

• Far Eastern - the most virulent (can cause severe forms of the disease);
• Siberian - less contagious;
• Western - the causative agent of two-wave encephalitis - causes mild forms of the disease.

The bite of an ixodid tick is the main cause. Due to damage to the body by a natural focal viral infection, which is dangerous for the membranes of the brain and spinal cord, meningitis and meningoencephalitis occur.

There are known cases of human infection with tick-borne encephalitis after consuming milk from tick-infected domestic animals. Therefore, you can only drink pasteurized or boiled milk.

Features of the tick-borne encephalitis virus are its poor resistance to high temperatures, disinfectants and ultraviolet radiation. Thus, when boiled, it dies within 2 minutes and cannot be preserved in the environment in hot sunny weather. However, at low temperatures it is able to maintain viability for a long time.

Incubation period

During a tick bite, some viruses begin to multiply in the subcutaneous tissue and tissue macrophages, while another part enters the blood and penetrates the vascular endothelium, lymph nodes, parenchymal organs, and into the tissue of the central nervous system, where they intensively multiply and accumulate. Treatment of tick-borne encephalitis is carried out using many groups of drugs that affect the virus itself and all parts of the pathological process.

Sometimes fulminant forms of tick-borne encephalitis are diagnosed (the first symptoms appear within a day) and protracted forms - the incubation period can include up to 30 days.

You should know that a patient with tick-borne encephalitis is not dangerous to others, as it is not contagious.

On average, the incubation period is 1-3 weeks, since the forms of development of the disease are different:

1. Lightning fast. With it, the initial symptoms appear already on the first day.
2. Lingering. In this case, the duration of the incubation period can be about a month, sometimes even a little longer.

Symptoms of tick-borne encephalitis

Tick-borne encephalitis is a viral infection that initially occurs under the guise of a common cold. It may go unnoticed by the patient, or may cause severe damage to the nervous system.

After a tick bite, the virus multiplies in tissues and penetrates the lymph nodes and blood. When the virus multiplies and enters the bloodstream, flu-like symptoms form.

Often the disease begins with the following symptoms:

• an increase in body temperature to 39-40 C and with chills characteristic of this condition,
• severe pain in the lower back and limbs,
• pain in the eyeballs,
• general weakness,
• nausea and vomiting,
• consciousness is preserved, but there is lethargy, drowsiness, and symptoms of stupor.

When the virus enters the membranes of the brain, and then into the substance of the brain, symptoms of disturbances in its activity appear (neurological):

• sensation of goose bumps, touches on the skin;
• skin sensitivity disorders;
• disturbances in muscle movements (first facial movements, then the ability to voluntarily make movements of the arms and legs is lost);
• convulsive seizures are possible.

Violations may later occur:

• cardiovascular system (myocarditis, cardiovascular failure, arrhythmia),
• digestive system - stool retention, enlarged liver and spleen.

All of these symptoms are observed against the background of toxic damage to the body - an increase in body temperature to 39-40 degrees C.

The most common and noticeable signs of an encephalitis tick:

• transient weakness of the limbs;
• weakness of the muscle tissue of the cervical region;
• feeling of numbness of the facial and cervical skin.

The outcome of tick-borne encephalitis comes in three main options:

• recovery with gradual long-term recovery;
• transition of the disease to a chronic form;
• death of a person infected with tick-borne encephalitis.

After a tick bite infected with the encephalitis virus, it is necessary to carry out emergency prevention for 3 days.

Forms of tick-borne encephalitis

Currently, the following forms of the disease are distinguished:

Febrile form of tick-borne encephalitis

Tick-borne encephalitis in this form occurs with a predominance of a febrile state, which can last from 2 to 10 days. The most typical manifestations include headache, weakness and nausea. In this case, neurological symptoms are mild.

Meningeal

Meningeal, which proceeds relatively favorably. It begins, like any other manifestation, with the phenomena of intoxication of the body:

• weakness,
• increase in body temperature,
• sweating

Then symptoms of brain damage appear (occipital headaches, vomiting, fear of light and impaired reflexes). Within two to three weeks, typical symptoms appear.

Meningoencephalitic

Meningoencephalitis is characterized by a two-wave temperature reaction. Each wave lasts from 2 to 7 days. At intervals of 1-2 weeks. The first wave occurs with general toxic symptoms, and the second with meningeal and cerebral signs. The course of this form is favorable, rapid recovery and absence of complications are observed.

Poliomyelitis form

It is observed in 30% of patients. It begins with general lethargy of the whole body, observed within 1-2 days. Accompanied by the following symptoms:

• weakness in the limbs, which can subsequently lead to numbness;
• characterized by pain in the neck;
• all violations described in the previous forms are possible;
• the ability to hold the head in an upright position disappears;
• loss of movement in the hands.

Motor pathologies progress over 1-1.5 weeks. From the beginning of the second to the end of the third week, the muscles begin to atrophy.

Polyradiculoneuritic form

It is observed rarely, in no more than 4% of cases. In addition to the symptoms of meningitis, with the development of this variant of tick-borne encephalitis, severe paresthesia (tingling) in the extremities and severe sensitivity in the area of ​​the fingers appear. Sensitivity in the central parts of the body is impaired.

As you can see, the signs of this disease can be completely different. Some forms of encephalitis are quite difficult to diagnose. That is why it is extremely important to consult a doctor in time, preferably before the appearance of disorders of the nervous system.

Signs of tick-borne encephalitis in children

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

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

The best measure to prevent tick-borne encephalitis in children and adults has been and remains vaccination. Vaccination against tick-borne encephalitis is recommended for everyone who lives or stays in epidemic foci.

Complications and possible consequences

The consequences of an encephalitis tick bite cannot be called pleasant. You can endlessly list why the encephalitis tick is dangerous and what its attack is fraught with.

Complications:

• Memory impairment.
• Headache.
• Complete or partial disturbances of movement and/or sensitivity in the limbs and facial area.
• Decreased muscle strength and volume (usually the upper shoulder girdle).

Diagnostics

The only answer to the question: what to do if suddenly bitten by an encephalitis tick is to deliver the patient to the nearest infectious diseases hospital as soon as possible.

When diagnosing tick-borne encephalitis, it is necessary to take into account a combination of three factors:

1. clinical manifestations (symptoms),
2. epidemiological data (time of year, whether the vaccine was given, whether there was a tick bite)
3. laboratory tests (analysis of the tick itself - optional, blood test, cerebrospinal fluid analysis, etc.).

I would especially like to note the fact that the virus can be detected in the tick itself. That is, if you are bitten by a tick, you must take it to a medical facility (if possible).

To accurately confirm the diagnosis, it is necessary to determine specific antibodies:

• immunoglobulin class M for encephalitis (IgM) – the presence indicates an acute infection,
• IgG - the presence indicates contact with an infection in the past, or the formation of immunity.

If both types of antibodies are present, this is a current infection.

All patients with tick-borne encephalitis must be examined for It is possible to become infected with both infections at the same time.

Treatment

Anti-encephalitis immunoglobulin therapy is considered an effective treatment method for tick-borne encephalitis at an early stage of detection. An inactivated vaccine and ribonucleic acid (RNA) are also most useful for successful recovery. Timely vaccination and protection against ticks are effective methods of preventing the complex course of the disease.

When prescribing treatment, they are guided by the principle of symptom relief. Therefore, medications are mainly prescribed to maintain the body. It includes:

• antipyretics,
• detoxifying drugs,
• vitamins,
• medications that normalize the body's water balance.

The patient is prescribed strict bed rest. The specific treatment regimen depends on the time that has passed since the first symptoms appeared.

Patients are discharged on days 14-21 of normal temperature. Dispensary observation is provided by an infectious disease specialist and a neurologist for 1 year after a febrile form with examination once every 6 months. After other forms of the disease - 3 years with quarterly examination.

Forecast

The meningeal and febrile form of the disease proceeds favorably in most cases. Meningoencephalitic, poliomyelitis and polyradiculoneuritic are significantly worse. Fatalities are 25-30%.

The consequences of tick-borne encephalitis can be decreased memory, headaches, and paralysis.

Prevention of tick-borne encephalitis

Prevention of tick-borne encephalitis is carried out in two directions:

• vaccination - the most reliable protection against tick-borne encephalitis is one’s own antibodies, which are produced in response to vaccination. Traditionally, they are held in advance in the autumn-winter period.
• preventive measures (nonspecific prevention).

Preventive measures also include:

1. refusal to consume dairy products that have not undergone heat treatment during the warm season;
2. timely vaccination (can be carried out both in the autumn-winter period and within 4 days after a tick is detected on oneself - different types of vaccines are used for this);
3. wearing clothing that covers the body (it is better to go out into nature in clothes with long sleeves and pants, the head should be covered with a cap);
4. promptly consult a doctor if any insects are detected (removing ticks on your own is not recommended at all);
5. use of tick repellents;
6. after returning home, you need to take off all your clothes and immediately take a shower, then you need to carefully examine your clothes “from the forest” and your body for ticks.

If you find a tick embedded in your skin on your body, immediately seek help from medical professionals - they will remove the insect and carry out anti-encephalitic vaccination.

Ixodid ticks carry dangerous diseases, one of which is tick-borne encephalitis. To protect yourself from it, to recognize the onset of infection in time, it is important to know the mechanism of infection, what signs you should pay attention to, how symptoms develop, what consequences arise, how the disease is treated and what preventive measures are.

What is tick-borne encephalitis

Tick-borne encephalitis is an infectious disease with natural focality. The carriers are ticks. It is isolated from 14 species of the genus Ixodes, and the main role is played by: Ixodes persulcatus and Ixodes ricinus.

Endemic areas: Siberia, the Urals, the Far East, Arkhangelsk, Leningrad, Irkutsk regions, about. Crimea, Perm, Primorsky region, rep. Tatarstan and others.

The peak incidence occurs in the warm season. This is due to people actively visiting natural hotspots against the backdrop of increased tick activity.

Few people know what an encephalitis tick looks like. Its outline resembles a spider. However, the structure is more primitive: instead of the typical division into a cephalothorax and abdomen, the body consists of a trunk and a mouth. The tick moves thanks to 4 pairs of short limbs. There is a hard shield on the back.

There are 2 mechanisms of human infection:

1. Transmissible - by bite. It has basic epidemiological significance.
2. The nutritional mechanism is recorded extremely rarely. Infection occurs through unboiled milk from a sick goat or cow with viremia.

The causative agent of encephalitis is a small RNA flavivirus coated with a protein coat. Its small size helps it penetrate various body barriers. Ultraviolet irradiation and high temperatures cause its destruction, and in the refrigerator the encephalitis virus remains in products for up to 2 months. In the body of the ixodid tick, the pathogen quickly penetrates all its organs with maximum accumulation in the digestive system. Therefore, the main danger to humans is the bite of an encephalitis tick.

Entry into the ovaries of females leads to the possibility of transmission of tick-borne encephalitis virions to offspring. Favorable conditions in the tick's body ensure transphase transmission: the virus moves along with the tick, maintaining the ability to infect. This mechanism is important for maintaining the focus of infection.

Spread of the virus in the body

The tick-borne encephalitis virus penetrates the skin or mucous membrane of the gastrointestinal tract. The first cells to meet it are the cells of the immune system - macrophages, which are found in almost all organs. They specialize in capturing and digesting infectious, foreign agents, and dead body cells.

The virus uses macrophages to recreate its own genetic material and assemble it, then leaves them, spreading hematogenously throughout the body. The ability of the encephalitis virus to integrate into the DNA of host cells can lead to long-term asymptomatic carriage, and suppression of immunity leads to a chronic course of the disease. Also, the encephalitis virus can cause a dangerous slow infection with a long incubation, after which the first symptoms of the disease quickly appear with a sharp deterioration.

The circulation of the virus in the blood is called viremia. It has 2 peaks: the first occurs during the initial propagation from the entrance gate. It does not last long and leads to the formation of foci of secondary reproduction in the liver, spleen, blood vessels, and lymph nodes. The second peak occurs at the end of the incubation period, when the encephalitis virus leaves the internal organs.

The first signs of the disease

The incubation period of tick-borne encephalitis is up to 30 days. When drinking milk, it is the shortest - up to several days. This period of time is dangerous due to imaginary well-being, as well as the fact that subsequently it is difficult to associate the symptoms of an encephalitis tick bite with an infection. You can see painless redness on the skin - a trace of suction. The development of ring erythema indicates the presence of two tick-borne infections: encephalitis and borreliosis.

In some patients, the incubation period of encephalitis is replaced by nonspecific symptoms - prodrome. These will be the first signs of encephalitis after a tick bite. They are often mistaken for the development of ARVI. This:

• headache;
• weakness;
• fatigue;
• rise in temperature;
• irritability;
• sleep disorders;
• muscle pain;
• weakness in arms, legs;
• paresthesia of the skin of the neck and face.

Symptoms

Symptoms of tick-borne encephalitis indicate the spread of virions and will help recognize the disease:

• hyperpyretic fever;
• chills;
• muscle pain;
• headache;
• facial redness;
• decreased heart rate;
• injection of eye vessels;
• drop in blood pressure.
• abdominal pain, bloating, white coated tongue;
• hepato- and splenomegaly develop when the pathogen penetrates the organs.
• meningeal signs (symptoms of irritation of the meninges).

If the central nervous system is damaged, the following are added:

1. symptoms of switching off, confusion%
2. episyndrome;
3. malignant hyperthermia;
4. symptoms of local brain involvement.

The first signs of infection when the motor neurons of the spinal cord are damaged look like flaccid paresis and paralysis.

Forms of tick-borne encephalitis

What symptoms tick-borne encephalitis will develop will be determined by a combination of conditions:

• place of virus introduction;
• duration of tick suction;
• the total number of ticks on one person;
• properties of the encephalitis virus strain;
• properties of the human immune system.

The division of the disease into forms is arbitrary, since cases are known that begin with clinical signs of one form and then have atypical development. Also, there may be no symptoms of encephalitis after a bite due to its asymptomatic course.

Let's take a closer look at the main forms of the disease:

Feverish

Most victims of a tick bite develop the so-called febrile form of tick-borne encephalitis. It has the following characteristics:

• sudden onset without prodrome;
• pale skin;
• muscle pain;
• pain in the eyeballs;
• a sharp rise in temperature to 39 degrees;
• severe intoxication;
• the appearance of symptoms of irritation of the meninges without inflammation (meningism).

The elevated temperature persists for 6 days. CSF analysis is not indicative. This is the most benign option. Asthenic phenomena remain at the exit.

Minengial

The meningeal form is often diagnosed. The virus does not cross the membranes of the brain. Signs of tick-borne encephalitis are:

• headache, dizziness;
• pain in the eyeballs, photophobia;
• cerebral vomiting without subsequent relief.

Patients are lethargic, positive persistent signs of irritation of the membranes of the brain are inhibited. The duration of fever is about 3 weeks. The cerebrospinal fluid contains a large number of lymphocytes and the protein content is increased.

Meningoencephalitic

The meningoencephalitic form appears when the tick-borne encephalitis virus crosses the blood-brain barrier. It is more severe due to the involvement of brain tissue. Fever reaches 40 degrees, its increase is accompanied by pronounced general somatic symptoms. The duration of fever reaches 2-3 weeks. Meningoencephalitis can be diffuse or focal.

In case of diffuse damage, the clinic is determined by general cerebral disorders: epileptic seizures, dysphagia, forced crying, reflexes of oral automatism, delirium.

With focal damage, the cranial nerves are involved, unilateral paresis and episyndrome occur. The clinic appears on the 3rd – 5th day of illness.

Poliomyelitis

The polio form affects the motor parts of the spinal cord. It begins with a prodromal period, after which the following symptoms of encephalitis appear:

• muscle twitching;
• weakness in arms, legs;
• numbness;
• soreness;
• cerebral manifestations;
• flaccid paresis of the neck, muscles of the shoulder girdle, arms.

CSF analysis will show lymphocytosis. There are persistent consequences of tick-borne encephalitis: paresis, atrophy, hypotrophy.

Tick-borne encephalitis with a two-wave course begins acutely, with meningeal and general somatic manifestations against the background of the first wave of fever. Analysis of the cerebrospinal fluid is not indicative; leukopenia and an increase in ESR are detected in the blood. The wave duration is up to 1 week. This is followed by a fever-free period, lasting up to 2 weeks. The subsequent second wave of hyperthermia is more severe. Lethargy, cerebral vomiting, meningeal signs, and local manifestations are noted. A blood test will show leukocytosis; CSF pressure is increased, lymphocytosis is pronounced. This option often ends well.

Polyradiculoneuritic

The polyradiculoneuritic form of tick-borne encephalitis occurs with damage to peripheral nerves: pain in the arms, legs, numbness, paresthesia. Landry's palsy may occur, starting in the legs or shoulder girdle and involving the brain stem.

The severity of the infection can be mild, moderate or severe. The type of tick-borne encephalitis is determined by the properties of the human body and the virus.

Few people know how encephalitis manifests itself in children. The infection manifests itself as fever. The tendency of children to generalize reactions makes it difficult to diagnose the disease in a timely manner. This means that the child’s body cannot localize the infectious process due to insufficiently developed barriers. Therefore, an increasing number of organ systems are involved with the appearance of striking, but not allowing for a correct diagnosis, symptoms:

• stomach ache;
• urinary retention;
• fever that cannot be controlled by medication;
• vomit;
• sore throat;
• various neurological symptoms.

The course is severe, with frequent mental disorders. Encephalitis is dangerous due to the development of episyndrome, status epilepticus (epistatus). Episyndrome is the appearance of epileptic seizures due to brain damage by a virus.

Epistatus is a series of epileptic attacks, coming one after another. In the interval between them, the person does not regain consciousness. This condition can cause swelling of the brain and lead to death. Due to the immaturity of the immune system, cases of chronic disease are common.

Consequences of tick-borne encephalitis

Some patients experience incomplete recovery from the disease. Then various neurological disorders come to the fore.

The main consequences of encephalitis are:

• persistent headache;
• dizziness;
• ataxia;
• pathologies of speech, hearing, vision;
• formation of paresis, paralysis;
• memory and attention impairment;
• asthenic symptoms;
• psychotic disorders;
• heart failure;
• pneumonia.

Diagnostics

Diagnosis of tick-borne encephalitis includes a set of measures:

Important! If several pincers were removed, they should be transported separately in labeled jars.

1. Collection of complaints, medical examination data.
2. Laboratory research methods will help establish a diagnosis.

A general blood test will show leukocytosis and increased ESR.

For meningeal, focal symptoms, a spinal puncture with examination of the cerebrospinal fluid will reveal signs of inflammation: lymphocytosis, increased protein.

The diagnostic standard is a method (ELISA) that allows one to evaluate the appearance of Ig G, M and track the increase in titer in paired sera (at the beginning and end of the disease).

It is possible to detect fragments of viral DNA using the polymerase chain reaction (PCR) method. The material is blood and liquor.

Differential diagnosis is carried out with other neuroinfections, tuberculous meningitis, borreliosis.

Treatment

Important! A tick found on the body must be immediately removed and taken to the laboratory.

If the diagnosis is verified, etiotropic treatment of tick-borne encephalitis is carried out using injections of special immunoglobulin. It is used in people examined in the first few days after tick ingestion. The administration regimen is selected by an infectious disease specialist.

Patients need to be monitored, so examination and treatment of encephalitis must be carried out in a hospital. Constant monitoring is especially important in children due to the risk of sudden deterioration of the condition and death.

In the infectious diseases department, patients are provided with strict bed rest. Treatment includes:

• interferons;
• antipyretics;
• detoxification;
• vitamin preparations;
• neuroprotectors.

If necessary, the following is included in treatment:

• hormones, diuretics to prevent cerebral edema;
• anticonvulsants;
• tranquilizers, neuroleptics;
• oxygen therapy.

Disease prevention

Disease prevention measures are divided into specific and nonspecific.

Specific planned prevention of tick-borne encephalitis consists of timely vaccination. The vaccine is given to adults and children.

Emergency prevention of encephalitis is carried out by administering immunoglobulin to all persons who come after a tick bite before laboratory confirmation of the diagnosis.

Non-specific methods include:

1. Using repellents.
2. When visiting a forested area, choose light-colored clothing that covers your arms and legs, with tight-fitting cuffs, and wear a headdress with a brim.
3. It is not recommended to sit on the grass, camp or spend the night in areas with tall grass.
4. Regular inspections during walks for timely detection of tick bites.
5. Boiling milk is mandatory.

Even a single and short-term contact with an encephalitis tick can trigger the development of the disease. Paying attention to your health will help you avoid serious consequences and death.

Tick-borne encephalitis is an acute viral disease of the nervous system. The causative agent of the disease is a specific virus, which often enters the human body through a tick bite. Infection is possible by consuming raw milk from sick animals. The disease manifests itself with 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 the disease. From this article you will learn how tick-borne encephalitis occurs, 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 in the warm season, when ticks are most active. Taiga, because the natural focus of the disease is predominantly located in the taiga. Siberian - due to the distribution zone, and Russian - due to detection mainly in Russia and description of a large number of virus strains by Russian scientists.

Causes of tick-borne encephalitis

The disease is caused by a virus belonging to the arbovirus group. The prefix "arbo" means transmission by arthropods. The reservoir of the tick-borne encephalitis virus is ixodid ticks, which live in the forests and forest-steppes 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 periodic epidemics to occur. 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 reaches a person through the bite of an ixodid tick. Moreover, tick suction 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 pathogen that has entered the human blood and the severity of the disease that has developed. The duration of the incubation period (the time from the pathogen entering the body until the first symptoms appear) also directly depends on the amount of virus.

The second method of infection is consumption of raw milk or food products made from thermally untreated milk (for example, cheese). More often, the disease is caused by the consumption of milk from goats, less often - from cows.

Another rare method of infection is the following: a tick is crushed by a person before being sucked on, but from contaminated hands the virus gets onto the oral mucosa if the rules of personal hygiene are not followed.

After entering the body, the virus multiplies at the site of penetration: in the skin, in the mucous membrane of the gastrointestinal tract. The virus then enters the blood and spreads throughout the body. The favorite place of localization of the virus is the nervous system.

Several types of virus have been identified that have a certain territorial affinity. A virus that causes less severe forms of the disease lives in the European part of Russia. The closer to the Far East, the worse the prognosis for recovery, and the more common deaths are.

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

Tick-borne encephalitis begins acutely. First, general infectious signs appear: body temperature rises to 38-40°C, chills, general malaise, diffuse headache, aching and nagging pain in the muscles, fatigue, and sleep disturbance occur. Along with this, there may be abdominal pain, sore throat, nausea and vomiting, redness of the mucous membrane of the eyes and throat. In the future, the disease may progress 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:

• febrile;
• meningeal;
• meningoencephalitic;
• polyencephalitic;
• polio;
• polioencephalomyelitis;
• polyradiculoneuritic.

Fever form characterized by the absence of signs of damage to the nervous system. The disease proceeds like a common cold. That is, the increase in temperature lasts 5-7 days, accompanied by general intoxication and general infectious symptoms. Then spontaneous recovery occurs. No changes in the cerebrospinal fluid (as in other forms of tick-borne encephalitis) are detected. If a tick bite has not been recorded, then usually there is not even a suspicion of tick-borne encephalitis.

Meningeal form, perhaps, is one of the most common. In this case, patients complain of severe headache, intolerance to bright light and loud sounds, nausea and vomiting, and pain in the eyes. As the temperature rises, meningeal signs occur: tension in the neck muscles, Kernig's and Brudzinski's symptoms. Possible disturbance of consciousness such as stupor, lethargy. Sometimes there may be motor agitation, hallucinations and delusions. The fever lasts up to two weeks. When carried out in the cerebrospinal fluid, an increase in the content of lymphocytes and a slight increase in protein are detected. Changes in the cerebrospinal fluid persist longer than clinical symptoms, that is, your health may improve, but the tests will still be poor. This form usually ends with complete recovery after 2-3 weeks. Often leaves behind a long-term asthenic syndrome, characterized by increased fatigue and fatigue, sleep disturbances, emotional disorders, and poor tolerance to physical activity.

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 minor twitching to pronounced contractions in amplitude). There may be a violation of the contraction of facial muscles associated with damage to the nucleus of the facial nerve in the brain. In this case, the eye on one side of the face does not close, food flows out of the mouth, and the face looks distorted. Among other cranial nerves, the glossopharyngeal, vagus, accessory, and hypoglossal nerves are most often affected. This is manifested by speech impairment, nasal voice, choking when eating (food enters the respiratory tract), impaired tongue movements, and weakness of the trapezius muscles. There may be disturbances in the rhythm of breathing and heartbeat due to damage to the vagus nerve or the centers of breathing and cardiac activity in the brain. Often with this form, epileptic seizures and disturbances of consciousness of varying degrees of severity occur, up to coma. An increase in the content of lymphocytes and protein is detected in the cerebrospinal fluid. This is a severe form of tick-borne encephalitis, in which cerebral edema may develop with dislocation of the brainstem and disruption of vital functions, as a result of which the patient may die. This form of tick-borne encephalitis often leaves behind paresis, persistent speech and swallowing disorders, which cause disability.

Polyencephalitic form characterized by the appearance of symptoms of damage to the cranial nerves on the 3-5th day of increased body temperature. The bulbar group is most often affected: glossopharyngeal, vagus, hypoglossal nerves. This is manifested by impaired swallowing, speech, and immobility of the tongue. The trigeminal nerves are also somewhat less commonly affected, which causes symptoms such as sharp pain in the face and facial deformation. At the same time, it is impossible to wrinkle your forehead, close your eyes, your mouth twists to one side, and food pours out of your mouth. Tearing 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, damage to the oculomotor nerve develops, which is manifested by strabismus and impaired movement of the eyeballs. This form of tick-borne encephalitis can also be accompanied by disruption of the respiratory and vasomotor centers, which can lead to life-threatening conditions.

Poliomyelitis form has this name due to its similarity with. It is observed in approximately 30% of patients. Initially, general weakness and lethargy, increased fatigue appear, against which minor muscle twitching (fasciculations and fibrillations) occurs. These twitchings indicate damage to the motor neurons of the anterior horns of the spinal cord. And then paralysis develops in the upper limbs, sometimes asymmetrical. It may be combined with sensory loss in the affected limbs. Within a few days, muscle weakness affects the muscles of the neck, chest and arms. The following symptoms appear: “head hanging on the chest”, “bent and stooped 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 (the muscles become exhausted and “lose weight”). Muscle recovery is almost impossible; muscle weakness remains with the patient for the rest of his life, making movement and self-care difficult.

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

Polyradiculoneuritic form manifested by symptoms of damage to peripheral nerves and roots. The patient experiences severe pain along the nerve trunks, impaired sensitivity, paresthesia (crawling sensation, tingling, burning, etc.). Along with these symptoms, ascending paralysis may occur, when muscle weakness begins in the legs and gradually spreads upward.

A separate form of tick-borne encephalitis has been described, characterized by a peculiar 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 and the condition improves. Then comes the “bright” period, which lasts 1-2 weeks. There are no symptoms. And then a second wave of fever occurs, along with which damage to 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, it “makes itself felt.” More often this is manifested by epileptic seizures and progressive muscle atrophy, which leads to disability.

The disease leaves behind a strong immunity.

Diagnostics

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

I would especially like to note the fact that the virus can be detected in the tick itself. That is, if you are bitten by a tick, you must take it to a medical facility (if possible). If a virus is detected in the tissues of a tick, preventive treatment is carried out - the introduction of a specific anti-tick immunoglobulin or the administration of Yodantipirin according to the regimen.

Treatment and prevention

Treatment is carried out using various means:

• specific anti-tick immunoglobulin or serum from those who have recovered from tick-borne encephalitis;
• antiviral drugs are used: Viferon, Roferon, Cycloferon, Amiksin;
• symptomatic treatment consists of 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 nonspecific and specific. Non-specific measures include the use of products that repel and destroy insects and ticks (repellents and acaricides), wearing clothing that is as closed as possible, a thorough examination of the body after visiting a forested area, and eating heat-treated milk.

Specific prevention can be emergency or planned:

• emergency is to use 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 Yodantipirin for 9 days after the bite according to the following regimen: 0.3 g 3 times a 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 consists of vaccination. The course consists of 3 injections: the first two with an interval of a month, the last - a year after the second. This administration provides immunity for 3 years. To maintain protection, revaccination is required once every 3 years.

Tick-borne encephalitis is a viral infection that initially occurs under the guise of a common cold.
It may go unnoticed by the patient, or may cause severe damage to the nervous system. The results of tick-borne encephalitis can also vary from complete recovery to permanent disability. It is impossible to get tick-borne encephalitis again, since the infection leaves a lasting lifelong immunity. In areas where this disease is endemic, it is possible to carry out specific prophylaxis and vaccination, which reliably protects against tick-borne encephalitis.

TV review, story on “Tick-borne encephalitis”:

Useful video about tick-borne encephalitis