Tick-borne encephalitis symptoms treatment prevention. Tick-borne encephalitis - symptoms, prevention and treatment

In spring, summer and even autumn, in addition to warm days, the health and life of people, as well as animals, are threatened by small ticks belonging to the class of arachnids. It is these blood-sucking creatures that after a human bite can cause a number of diseases, the most popular of which is tick-borne encephalitis. The latter will be discussed today.

What is tick-borne encephalitis (TBE)?

Tick-borne encephalitis- an inflammatory disease of the brain and / or spinal cord of an infectious nature, which develops as a result of a bite by a virus-carrying tick.

Other names for the disease are spring-summer tick-borne meningoencephalitis, tick-borne viral encephalitis, TBE or TVE.

The causative agent of the disease- arbovirus Tick-borne encephalitis virus, belonging to the genus Flavivirus (Flavivirus), the carriers of which are Ixodes ticks of the species "Ixodes persulcatus" and "Ixodes ricinus".

The main signs of the disease- neurological (paresis, convulsions, photophobia, discoordination of movements) and mental disorders, persistent intoxication, up to death.

The diagnosis is established on the basis of PCR of blood and cerebrospinal fluid.

Treatment mainly includes the introduction of immunoglobulin, antiviral drugs and symptomatic therapy.

The main regions of distribution of encephalitis ticks are Siberia, East Asia and Eastern Europe, where there are forests.

Pathogenesis and periods of tick-borne encephalitis

The incubation period of CE is from 2 to 35 days.

The most vulnerable to tick-borne infection are the subcortical nodes and the cerebral cortex, the cells of the meninges, the structures of the bottom of the third ventricle.

Penetrating into the body, the flavivirus infection is adsorbed on the surface of immune cells - macrophages, after which the virus penetrates into them, where RNA replication, capsid proteins and the formation of the virion are performed. Then the viruses leave the cell through the modified membranes and go to regional lymph nodes, cells of the liver, spleen, settle on the inner walls (endothelium) of blood vessels. This is the second period of virus replication.

The next stage of TBE damage to the body is the penetration of the virus into the neurons of the cervical spinal cord, cells of the soft tissues of the meninges and cerebellum.

Further, the processes of disintegration of axial cylinders and demyelination, atrophy and destruction of neurons develop. Edema of the brain and spinal cord appears, as well as increased permeability of the walls of blood vessels, which leads to the growth of microglial cells and spontaneous hemorrhages.

After that, liquorodynamic disorders develop - a condition when the secretion and circulation of cerebrospinal fluid (CSF) is disturbed, as well as its interaction with the circulatory system. In the pathological process, diffuse infiltration of nerve tissues by mononuclear cells, polynuclear cells and plasma cells can be observed, especially in the perivascular space.

Histological studies do not have a clear picture of changes in EC.

Distribution areas and statistics

According to WHO, about 12,000 cases of TBE are recorded every year. Of these, about 10% falls on the regions of Russia, mainly Siberia, the Urals, Altai, Buryatia, and the Perm Territory.

The percentage of those bitten by ticks and the detection of TBE does not exceed 0.4-0.7%

Among other regions where the most bites and incidences of TBE are recorded are Northern, Central and Eastern Europe, Mongolia, China, and others where there are large forest areas.

ICD

ICD-10: A84
ICD-10-KM: A84.1, A84.9, A84.8 and A84.0
ICD-9: 063

Symptoms

The greatest number of bites and infection with flavivirus infection is recorded in spring and early autumn.

The places where ticks are most found are forests and park areas where grass is present.

Classification

The classification of tick-borne encephalitis is as follows:

With the flow:

Spicy;
Subacute;
Chronic.

By form:

Feverish(about 50% of patients) - is characterized mainly by a febrile condition of the patient, with jumps in body temperature from high to high, chills, weakness, body aches and other clinical manifestations for several days. With remission of the disease, the temperature returns to normal, however, weakness, excessive sweating, tachycardia attacks may be present even after normal laboratory parameters for blood and cerebrospinal fluid tests.

Meningeal(about 30% of patients) - is characterized by damage to the membranes of the brain and spinal cord, while the leading symptom of the disease already on the 3-4th day are signs. The main symptoms are high body temperature (about 14 days), severe headache, nausea and vomiting, stiffness (tightness) of the neck muscles, skin hypersensitivity to contact with clothing (up to pain), symptoms of Kernig, Brudzinsky. When the temperature subsides, there are residual effects - photophobia, asthenia, bad mood.

Focal(about 20% of patients) - the most severe form of TE with an unfavorable prognosis, characterized by simultaneous damage to the brain and spinal cord. Among the main symptoms are a sharp rise in body temperature to 40 ° C and above, drowsiness, convulsions, vomiting, hallucinations, delirium, fainting, incoordination in movement, tremor, paresis, paralysis, severe pain in the head and back. There is a two-wave subspecies of the focal form - when a high temperature appears at the beginning of the disease, which normalizes after a while, after which neurological disorders appear that are characteristic of tick-borne encephalitis.

Progredient- the development of the disease occurs against the background of other forms and is characterized by symptoms after a few months or years. In the pathogenesis lies persistent violations after the disease in the functioning of the brain.

By localization

- stem;
- Cerebellar;
- mesencephalic;
- Hemispherical;
- Diencephalic.

Depending on the affected brain substance:

White matter (leukoencephalitis);
gray matter (polioencephalitis);
Simultaneously both white and gray matter (Panencephalitis);
Some parts of the spinal cord (encephalomyelitis).

Diagnostics

Diagnosis of tick-borne encephalitis includes:

Anamnesis, examination, identification of complaints with symptoms of the disease.
In the first 3 days after the bite, an express diagnosis of DNA or encephalitis virus antigens can be carried out using ELISA, PCR, RSK or RTGA. Also, using PCR, a bacteriological examination is carried out for the presence of Borrelia bacteria in the body in order to timely detect the presence of tick-borne borreliosis, if any. Blood is taken again 14 days after the first sampling.
With the help of a puncture, the cerebrospinal fluid (cerebrospinal fluid - fluid of the brain and spinal cord) is taken and further examined.
and blood test

Tests for tick-borne encephalitis show the following data:

The presence in the blood serum from the first days of the disease of immunoglobulins of the IgM class, which reach a maximum concentration in the first 10 days of CE;
The presence of IgG antibodies from the 7th day from the onset of the disease, which may be present for several more months in the blood;
Increased erythrocyte sedimentation rate ESR and leukocytosis;
Slight increase in blood protein;
Lymphocytic pleocytosis at the level of 20-100 cells in 1 µl of CSF.

Treatment

Treatment of tick-borne encephalitis in view of the severity of the disease is carried out in a hospital. The patient is not placed in the infectious department, because. it is not contagious and does not pose a threat to other people.

The treatment regimen for tick-borne encephalitis includes:

1. Peace;
2. Etiotropic therapy;
3. Pathogenetic therapy;
4. Symptomatic therapy;
5. Rehabilitation treatment.

Remember, the sooner a person seeks specialized help after a tick bite and the first signs of illness appear, the more favorable the prognosis for recovery and the prevention of irreversible processes in the brain and spinal cord.

1. Peace

To accumulate the strength of the patient, as well as to prevent unnecessary irritation of the nervous system, a strict bed rest is prescribed. The room is shaded, potential sources of noise are removed.

In such a place, the patient will be able to relax as much as possible, and symptoms in the form of photophobia, headache, and others are minimized.

2. Etiotropic therapy

Etiotropic treatment implies the relief of infection and its further spread throughout the body.

First of all, in the first four days after a tick bite, the administration of anti-tick immunoglobulin is prescribed. This serum prevents the development of complications if the victim does not have a vaccination against tick-borne encephalitis.

If a person did not apply for medical help during this period, then anti-tick immunoglobulin is administered in the first three days from the moment the first signs of TBE appear.

In addition, antiviral drugs are used - Ribavirin, Groprinasin, Cytosinarabinose (iv for 4-5 days at a dose of 2-3 mg per 1 kg of body weight per day), interferon preparations (Tiloron).

Anti-tick globulins are produced on the basis of donated blood serum taken from people living in areas with a high prevalence of TBE.

Antibiotics for tick-borne encephalitis are not prescribed, because. this disease has a viral nature of the disease, against which antibacterial drugs are not effective.

3. Pathogenetic therapy

The goal of pathogenetic therapy is to stop the pathological mechanisms and processes of the disease that disrupt the functioning of the brain and other components of the nervous system, threatening the life of the patient.

The following groups of drugs can be noted here:

Diuretics (diuretics)- the use of these drugs removes excess fluid from the body, thereby removing swelling from the brain, spinal cord and other parts of the body, reduces intracranial pressure, which as a result prevents swelling of the brain.

Popular diuretics for CE are Diacarb, Furosemide, Mannitol, Glycerol.

Glucocorticoids (GC)- a group of hormonal drugs used in moderate and severe inflammatory processes, which also have anti-inflammatory, anti-edematous, anti-allergic activities. In addition, GCs support the work of the adrenal cortex, thereby preventing their depletion.

Popular GCs for CE are Dexamethasone (IV or IM at a dose of 16 mg/day, 4 mg every 6 hours), Prednisolone (for bulbar disorders and syncope, parenterally, at a dose of 6-8 mg/day). kg, and without these manifestations - tablets, at a dose of 1.5-2 mg / kg per day).

Antihypoxants- drugs and devices that are used to prevent oxygen starvation of the brain and other parts of the body.

Popular antihypoxant drugs are Sodium Oxybutyrate, Actovegin, Cytochrome C, Mexidol.

Among the methods of maintaining the required level of oxygen, humidified oxygen (introduced through nasal catheters), hyperbaric oxygenation, artificial lung ventilation (ALV) are used.

4. Symptomatic therapy

Symptomatic treatment is aimed at maintaining the body's performance, preventing clinical manifestations associated with the disease and further development of pathological processes, which in general helps the body cope with CE faster.

These medicines are:

Anticonvulsants- are used to prevent seizures and seizures of epilepsy: "Benzonal", "Difenin", "Finlepsin".

Muscle relaxants- are used to relax muscle tissue, which is important if the muscles are periodically in good shape: Mydocalm, Sirdalud.

To maintain and stimulate the transmission of neuromuscular signals- prevent paresis, paralysis, tremor: Neuromidin, Prozerin.

Antiarrhythmic- are used to bring the heart rate to normal values: Aymalin, Novocainamide.

Angioprotectors- are used to reduce the permeability of the walls of blood vessels and improve their health, which prevents internal hemorrhages: Cavinton, Pentoxifylline, Vinpocetine.

Antipsychotics- are used to prevent involuntary movements and normalize the mental state of the patient: "Aminazin", "Sonapax", "Triftazin", "Sibazon", "Amitriptyline".

Metabolic drugs- are assigned to normalize metabolic processes: "Piracetam", "Phenibut".

5. Rehabilitation treatment

To restore the body, mainly the functioning of the brain and spinal cord, a neurologist can prescribe a number of the following measures and drugs:

Vitamin and mineral complexes;
Nootropics - aimed at improving brain activity: "Aminalon", "Piracetam", "Pyrititol";
Therapeutic physical education (LFK);
Physiotherapy;
Massage;
Sanatorium-resort rest.

Forecast and consequences

The prognosis for tick-borne encephalitis largely depends on the timely visit to the doctor and adequate methods of therapy, the severity of the disease, the patient's health at the time of infection with the virus.

If we talk about the forms of the disease, then:

when febrile - most recover completely;
with meningeal - also a favorable outcome, however, there may be some chronic manifestations of migraine and other types of headache;
with focal - the prognosis is conditionally favorable, because with such a diagnosis, a lethal outcome is observed in approximately 30% of patients, while others develop persistent disorders of the nervous system in the form of paralysis, convulsions, and mental disorders.

Folk remedies

Important! Before using folk remedies against tick-borne encephalitis, be sure to consult your doctor!

Mint, lemon balm, periwinkle. Pour in 1 tbsp. spoon, in different containers 500 ml of boiling water, and periwinkle. Put them for 15 minutes on a slow fire under the lid, then set aside for 30 minutes to infuse, strain. You need to drink the remedy 1/3 or half a glass 3 times a day, 15 minutes after a meal, or before a meal, changing each of the decoctions in turn.

Motherwort. 1 st. Pour 500 ml of boiling water over a spoonful of chopped raw herbs and put on a slow fire for 15 minutes, then set aside to infuse and cool for 45 minutes, strain the product. Drink half a glass at lunch, in the evening and at bedtime, before or after meals.

Valerian. Pour 1 teaspoon of the roots with a glass of boiling water, cover the vessel with a lid and wrap it with a towel, leaving the product for 2 hours to infuse. Strain and drink 1 tbsp. spoon 4 times a day, 30 minutes before or 30 minutes after a meal. This remedy improves blood circulation, relieves the inflammatory process, and has a beneficial effect on the arachnoid membrane of the brain.

Juices. Drink freshly squeezed juices from the following plants: 9 parts carrots and 7 parts celery leaves. You can also add 2 parts of parsley roots or 3 parts of spinach juice here.

Peony. Pour 1 tbsp. a spoonful of peony rhizomes 500 mg of boiling water, put the product for 30 minutes to boil over low heat, then set aside for 1 hour under a covered lid. Strain the product and drink 100 ml 3 times a day for 30 days, then take a 2-3 week break and repeat the course.

Rhodiola rosea. Pour the crushed roots of Rhodiola rosea in a dark glass container with alcohol. Put the product in a dark cool place for 7 days to infuse. Take tincture 15-20 drops 3 times a day, diluted in 1 tbsp. a spoonful of boiled water. Course - until recovery.

Prevention

Prevention of tick-borne encephalitis includes:

Compliance with the rules of safe behavior in nature. If you go on vacation in forested areas, choose places with a minimum amount of grass, otherwise dress in such a way that the tick cannot penetrate through the gaps under your clothes. However, in this case, do not forget to periodically inspect yourself for the presence of a tick, especially this should be done first thing upon arrival home.

Treat clothes and exposed areas of the body with anti-mite products - various repellents can be purchased at many stores, or ordered online.

If you removed the tick from your clothes or body - in no case do not crush it with your bare hands, and in general, avoid contact with the tick with your bare hands so that its contents, if it is a carrier of the virus, do not get on the skin, and you forget about it touched your mouth or food. It is best to burn the caught tick or pour boiling water over it.

Local authorities must treat forests with anti-tick agents in order to eradicate them, which, by the way, was successfully done during the Soviet era.

Gardening and forestry workers must wear special protective clothing.

It is recommended to buy dairy products in epidemiological zones from trusted persons/manufacturers.

Immunization of the population.

Vaccination against tick-borne encephalitis

Vaccination against TBE is recommended for people who live in areas with an increased epidemiological situation for this disease. However, it is worth considering that the encephalitis vaccine does not prevent the disease, but only aims to make it milder while minimizing the risk of developing complications of the disease. Immunity to arbovirus infection is developed after three vaccinations for about 3 years.

Popular vaccines against tick-borne encephalitis are KE-Moscow, Encepur, FSME-Immun, EnceVir.

Which doctor will contact?

Video

Encephalitis is a group of diseases characterized by inflammation of the brain. On the territory of the Russian Federation, tick-borne encephalitis is widespread - a viral infectious disease, the carriers of which are ticks. This viral infection affects brain cells, nerve endings and, if not properly prevented or treated, can be fatal. We already discussed how to prevent infection in the previous article “Prevention: how to protect yourself from a tick bite”. How to suspect tick-borne encephalitis and what to do if it seems to you that it really is? You will learn about this from the material below.

Symptoms of tick-borne encephalitis

Tick-borne encephalitis (alternative names - spring-summer or taiga encephalitis) is an acute viral pathology that is part of the group of natural focal diseases. Ixodid ticks carry it, but a person can also become infected from wild or domestic animals and birds, as well as after drinking raw cow (goat) milk.

The incubation period for viral encephalitis is 10 to 30 days. The development of the disease begins immediately after the pathogen enters the bloodstream. Moreover, only a small amount is enough, which is brought in with saliva, even if the tick has stuck to the skin for a short time.

The development of encephalitis is accompanied by severe muscle pain, headache, fever up to 40 degrees Celsius, sleep disturbances, nausea and vomiting. The mentioned symptoms can be observed from a week to two, after which (if left untreated) more serious consequences occur.

The clinical picture depends on the forms of pathologies. There are such types:

Feverish. The least dangerous type of pathology. It manifests itself in the form of a mild fever, after which the patient is cured without harm to health.
Meningeal. A fairly common form, manifests itself in the form of headaches and stiffness of the muscles of the back of the neck. The pathology is accompanied by Kernig's symptom (the patient's leg, lying on his back, passively flexes at an angle of 90 ° in the hip and knee joints (first phase of the study), after which the examiner makes an attempt to straighten this leg in the knee joint (second phase). If the patient has meningeal syndrome, it is impossible to straighten his leg in the knee joint due to a reflex increase in the tone of the leg flexor muscles; with meningitis, this symptom is equally positive on both sides) This form lasts from 6 to 14 days, after which remission occurs.
Meningoencephalitic. It is dangerous because in 20% of cases it leads to the death of the patient. In addition to the symptoms listed above, it is accompanied by hallucinations and delusions, psychomotor agitation, muscle twitching.
Polio. Symptoms are clear from the name and are similar to the clinical manifestations of poliomyelitis. The patient suffers from a fever, and the muscles of his neck and arms become paralyzed.
Polyradiculoneuric. A very rare form of infection. The nerve nodes are affected, which manifests itself in numbness and tingling of the limbs.

For an accurate diagnosis of the disease, it is necessary to take a blood test. The disease is identified due to the presence of antibodies produced by the human immune system.

Treatment of tick-borne encephalitis

The disease is treated exclusively in a hospital. The patient must be placed in the infectious department. For treatment, immunoglobulin, antibacterial drugs, stimulants and B vitamins are used.

After suppression of the virus during the recovery period, the patient is given neuroprotectors and a course of physiotherapy exercises and (or) massage is prescribed. Upon completion of the course of therapy, residual effects caused by encephalitis are possible - atrophy of the shoulder girdle, extended epileptic seizures with muscle twitching.

Preventive actions

The best way to avoid infection and long-term treatment for tick-borne encephalitis is through preventive measures. Usually, vaccinations are used to protect the body, which are given in advance.

However, at present there is another effective remedy - iodantipyrin. This drug has passed clinical trials at the Siberian State Medical Institute, where it showed more than 99% effectiveness: out of 460 people taking Jodantipyrine, only 3 developed the virus.

Prevention before a tick bite with iodantipyrine is carried out according to the following scheme:

2 tablets 1 time per day during the entire spring-summer period, when there is a risk of tick bites and virus infection;

2 tablets 3 times a day 2 days before visiting an area where ticks can live.

If the tick has already stuck to the skin, it must be removed with tweezers or thread, and then drink a course of iodantipyrin according to the following scheme:

3 tablets 3 times a day for 2 days;
2 tablets 3 times a day for the next 2 days;
1 tablet 3 times a day for the next 5 days

After the end of the course, you should re-donate blood for analysis.

Tick-borne encephalitis with symptoms of damage to cerebral structures is 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 severely disabled. However, in the case of the introduction of a specific vaccine in the body, a special protection against encephalitis is developed. Therefore, doctors urge people to be vaccinated against the encephalitis tick.

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

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

intense discomfort in the joints, sacral region;
cephalgia - soreness in the head, especially in the area of \u200b\u200bthe eyeballs;
nausea and even indomitable vomiting - often do not bring relief to 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 making the correct diagnosis does not cause difficulties for specialists:

increased susceptibility to sunlight;
violations of superficial, as well as deep sensitivity;
failures in the muscular system - the activity is lost first of the mimic 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, eat food 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 of a person.

Incubation period

By itself, the 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 immune system and a large dose of tick-borne virus that entered the bloodstream after a tick bite, encephalitis can form in just 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 the nervous structures occur by 8–21 days from the moment of infection. Less often, a fulminant form is observed - encephalitis occurs in 1–3 days, or a protracted variant - tick-borne infection makes itself felt by the end of the month after the virus enters the body.

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

Causes

The basis of infection with human tick-borne encephalitis in 2/3 of cases, of course, is the bite of a carrier tick. The defeat of cerebral structures by a viral infection occurs after the injection of particles dangerous for the nervous system into the bloodstream.

A characteristic of the tick-borne virus is its low resistance to high temperatures and UV rays. Therefore, it practically cannot exist outside the carrier's body. 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 an insect, but also from taking milk from an infected cow - an alimentary route of infection. Less commonly, the virus enters through scratched skin that contains tick feces or particles of its damaged body.

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

tick bite;
alimentary - through products from infected animals;
fecal-oral through dirty hands, on which there are waste products of ticks;
through microtraumas on the integumentary tissues - the virus is introduced with combing the skin on which the tick was present.

Encephalitis can be avoided by carefully following the generally available safety rules.

Diagnostics

The identification of the disease after a tick bite is facilitated by the correct collection of anamnesis - the doctor asks the person whether he has recently visited the forest, whether there have been trips to those regions where there is 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. This is especially true if encephalitis is suspected in children. After all, the baby is far from always able to answer the questions of interest to the 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 antibody titer to the virus - its decrease / increase in two sera, which were taken with a break of two weeks.

From additional instrumental studies to establish encephalitis in humans, the doctor may recommend electroencephalography and computed tomography of the brain. After comparing all the information from the diagnostic procedures, the specialist gives his opinion and selects the optimal therapy.

Medical tactics

To effectively combat the signs of tick-borne encephalitis, treatment should be started on the day of the bite and in full. Antiencephalitic immunoglobulin therapy has proven itself excellently. It is beneficial to administer an inactivated ribonucleic acid vaccine if the procedure is carried out immediately 1.5–3 hours after a suspected encephalitis after a tick bite.

For the complex treatment of 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 its help that the infected person's own immune system gets the opportunity to quickly cope with the insidious neurotropic virus.

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

antipyretics - antipyretics;
detoxifying solutions - accelerating the removal of toxins from tissues;
vitamins - to increase immunity, improve the functioning of the nervous system;
medicines that correct the water-salt balance in the body;
antiemetics;
analgesics.

Severe manifestations of tick-borne encephalitis in children. Therefore, their doctors observe longer, they are in no hurry to discharge them from the hospital for outpatient supervision by neuropathologists. In the future, dispensary control of babies should be at least three years.

Prevention

As such, the specific prevention of tick-borne encephalitis is a three-time vaccination. After all, the body then produces anti-mite antibodies. The National calendar of universal immunization of the population does not provide for such a procedure. However, each person of their own free will can go to the doctor to be vaccinated against tick infection.

Non-specific disease prevention:

refuse to use unpasteurized products, especially dairy products;
when traveling to the forest, wear clothes that will completely cover all parts of the body;
contact a medical institution in a timely manner if a case of a tick bite has been detected;
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 countryside, to the country.

Great attention is paid to the preservation of the health of the population by medical workers. However, each person must 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 encounters with forest insects, the percentage of complications of tick-borne encephalitis among bitten persons is low. The prognosis largely depends on the type of pathology and the initial state of health of the patient.

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

persistent headaches;
tendency to epilepsy;
various violations of sensitivity;
decrease in memory and intellectual abilities.

In a severe course of the disease, an encephalitis tick in people provokes such complications as paralysis of the muscles of the arms and lower extremities, a sharp weakening of brain activity, and chronic focal disorders. People become severely disabled, and it is not possible to return them to society.

The prognosis is more favorable for the 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 of the nervous system. Its main sources are ixodid ticks of two species - taiga and European forest. 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 and 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 bitten by an encephalitic tick, the virus enters the bloodstream in 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 bitten people can get sick from an infected individual).

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

Far East - 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 the defeat of the body by a natural focal viral infection, dangerous for the membranes of the brain and spinal cord, meningitis and meningoencephalitis occur.

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

The tick-borne encephalitis virus is characterized by low resistance to high temperatures, disinfectants and ultraviolet radiation. So, when boiled, it dies after 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 of the viruses begin to multiply in the subcutaneous tissue and tissue macrophages, while another part enters the bloodstream and penetrates into the vascular endothelium, lymph nodes, parenchymal organs, and into the tissues 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 - the incubation period can include up to 30 days.

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

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

Lightning. With her, the initial symptoms appear already in the first day.
Protracted. 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 can go unnoticed by the patient, and can cause severe damage to the nervous system.

After a tick bite, the virus multiplies in the tissues, penetrates into 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 up 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 lethargy, drowsiness, and symptoms of stupor are present.

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

sensation of goosebumps, touches on the skin;
skin sensitivity disorders;
violations of muscle movements (first mimic, then the ability to voluntarily make movements of the arms and legs is lost);
seizures are possible.

Later violations may occur:

cardiovascular system (myocarditis, cardiovascular insufficiency, arrhythmia),
digestive system - stool retention, enlargement of the liver and spleen.

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

The most common and noticeable signs of an encephalitis tick:

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

The outcome of tick-borne encephalitis occurs in the form of three main options:

recovery with a gradual long-term recovery;
the 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 prophylaxis within 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 proceeds with a predominance of a feverish state, which can last from 2 to 10 days. The most characteristic manifestations are headache, weakness and nausea. At the same time, 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 join (occipital headaches, vomiting, fear of light and impaired reflexes). Typical symptoms appear within two to three weeks.

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 passes with general toxic symptoms, and the second with meningeal and cerebral signs. The course of this form is favorable, there is a rapid recovery and no complications.

Polio form

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

weakness in the limbs, which can later lead to numbness;
characteristic pain in the neck;
all violations described in the previous forms are possible;
the ability to keep the head upright is lost;
loss of movement in the arms.

Motor pathologies progress within 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, no more than in 4% of cases. In addition to the symptoms of meningitis, with the development of this variant of the course of tick-borne encephalitis, pronounced paresthesias (tingling) in the extremities and strong sensitivity in the fingers appear. Violated sensitivity in the central parts of the body.

As you can see, the symptoms of this disease can be completely different. Some forms of encephalitis are difficult to diagnose. That is why it is extremely important to consult a doctor in time, preferably even before the onset of disorders from 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 a headache, expressed by a rise in body temperature;
sleep disorders;
disorders of the eyeball;
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 indicated for everyone who lives in epidemic foci or stays in them.

Complications and possible consequences

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

Complications:

Memory deterioration.
Headache.
Complete or partial disturbances of movements and / or sensitivity in the limbs, mimic area.
Reducing the strength and volume of muscles (often 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 as soon as possible to the address of the nearest infectious diseases hospital.

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

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

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 taken to a medical facility (if possible).

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

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

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

All patients with tick-borne encephalitis must be examined for, because. possible simultaneous infection with both infections.

Treatment

An effective method of treatment for tick-borne encephalitis at an early stage of detection is anti-encephalitis immunoglobulin therapy. Also, the inactivated vaccine and ribonucleic acid (RNA) are most useful for a 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, funds are mainly prescribed to maintain the body. It includes:

antipyretic,
detox drugs,
vitamins,
drugs that normalize the water balance of the body.

The patient is placed on strict bed rest. The specific treatment regimen depends on the time elapsed since the onset of the first symptoms.

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

Forecast

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

The consequence of tick-borne encephalitis may be memory loss, headaches, 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 own antibodies that are produced in response to vaccination. Traditionally, they are held in advance in the autumn-winter period.
preventive measures (non-specific prophylaxis).

Preventive measures also include:

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

If a tick has been found on the body that has stuck into the skin, then immediately seek help from medical workers - they will remove the insect and carry out anti-encephalitic vaccination.

Everyone is afraid of tick bites, because everyone knows about the possible dangerous consequences of such a short meeting with a blood-sucking insect. In addition to an unpleasant sensation, a tick bite threatens to become infected with a viral infection - tick-borne encephalitis, the outcome of which can be very sad.

What is this infection - tick-borne encephalitis virus? How is the disease caused by it manifested? Is it possible to cure this disease and what complications threaten the sick? What is the prevention of tick-borne encephalitis?

What is tick-borne encephalitis

Tick-borne encephalitis is a viral natural focal infection that is transmitted after tick bites and affects mainly the central nervous system. The causative agent of tick-borne encephalitis belongs to the Flavivirus family of viruses, which are transmitted by arthropods.

This disease has many clinical manifestations. Scientists have long tried to study the disease, but only in the first half of the 20th century (in 1935) they were able to identify the causative agent of tick-borne encephalitis. A little later, it was possible to fully describe the virus, the diseases it causes, and how the human body reacts to it.

This virus has the following features:

reproduces in carriers, the reservoir in nature is a tick;
tick-borne encephalitis virus is tropic or, in other words, tends to the nervous tissue;
active reproduction begins in the spring-summer period from the moment of “awakening” of ticks and tick-borne encephalitis;
the virus does not live long without a host, it is quickly destroyed by ultraviolet radiation;
when heated to 60 ° C, it collapses in 10 minutes, boiling kills the causative agent of tick-borne encephalitis in just two minutes;
he does not like chlorine-containing solutions and lysol.

How is tick-borne encephalitis transmitted?

The main reservoir and source of infection are ixodid ticks. How does the tick-borne encephalitis virus enter the body of an insect? 5-6 days after the bite of an infected animal in a natural focus, the pathogen penetrates into all organs of the tick and concentrates mainly in the reproductive and digestive systems, salivary glands. There, the virus remains for the entire life cycle of the insect, and this is from two to four years. And all this time after a tick bite of an animal or a person, tick-borne encephalitis is transmitted.

Infect, maybe, absolutely every resident of the area where there are outbreaks of infection. The statistics are disappointing for a person.

Depending on the region, the number of infected ticks ranges from 1–3% to 15–20%.
Any animal can be a natural reservoir of infection: hedgehogs, moles, chipmunks, squirrels and voles, and about 130 other species of mammals.
According to epidemiology, tick-borne encephalitis is distributed from Central Europe to Eastern Russia.
Some species of birds are also among the possible carriers - hazel grouse, finches, blackbirds.
There are known cases of infection with human tick-borne encephalitis after drinking milk from tick-infected domestic animals.
The first peak of the disease is recorded in May-June, the second - at the end of summer.

Ways of transmission of tick-borne encephalitis: transmissible, during the bite of an infected tick, and alimentary - after eating infected foods.

The action of the tick-borne encephalitis virus in the human body

The place of frequent localization of the pathogen in the body of an insect is the digestive system, reproductive apparatus and salivary glands. How does the tick-borne encephalitis virus behave after it enters the human body? The pathogenesis of tick-borne encephalitis can be described as follows.

During the course of the disease is conditionally divided into several periods. The initial phase proceeds without visible clinical manifestations. Next comes the phase of neurological changes. It is characterized by typical clinical manifestations of the disease with damage to all parts of the nervous system.

The outcome of tick-borne encephalitis occurs in the form of three main options:

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

The first signs of tick-borne encephalitis

The first days are the easiest and at the same time dangerous in the development of the disease. Lungs - since there are no clinical manifestations of the disease yet, there is no hint of infection. Dangerous - because due to the lack of obvious signs, you can lose time and encephalitis will develop with full force.

The incubation period of tick-borne encephalitis sometimes reaches 21 days, but on average lasts from 10 days to two weeks. If the virus enters through contaminated products, it is shortened and is only a few days (no more than 7).

Approximately in 15% of cases, after a short incubation period, prodromal phenomena are observed, but they are nonspecific, it is difficult to suspect this particular disease from them.

The first signs of tick-borne encephalitis appear:

weakness and fatigue;
various types of sleep disorders;
a feeling of numbness of the skin of the face or torso may develop;
one of the frequent signs of tick-borne encephalitis are various variants of radicular pain, in other words, unrelated pains appear along the nerves extending from the spinal cord - in the arms, legs, in the shoulder area and other departments;
already at this stage of tick-borne encephalitis, mental disorders are possible, when an absolutely healthy person begins to behave unusually.

Symptoms of tick-borne encephalitis

From the moment the tick-borne encephalitis virus enters the bloodstream, the symptoms of the disease become more pronounced.

During the examination of a person, the doctor detects the following changes in the condition:

in the acute period of tick-borne encephalitis, the face, skin of the neck and body are reddened, the eyes are injected (hyperemic);
blood pressure decreases, the heartbeat becomes rare, changes appear on the cardiogram, indicating a conduction disorder;
during the height of tick-borne encephalitis, breathing quickens and shortness of breath appears at rest, sometimes doctors register signs of developing pneumonia;
the tongue is covered with a white coating, as in the defeat of the digestive system, bloating and constipation appear.

Forms of tick-borne encephalitis

Depending on the location of the pathogen in the central nervous system of a person, various symptoms of the course of the disease may appear. An experienced manifestation specialist can guess which area of the nervous system has been attacked by the virus.

There are various forms of tick-borne encephalitis.

Diagnostics

Diagnosis of tick-borne encephalitis, as a rule, is delayed due to a blurred initial clinical picture. Patients in the first days of the disease complain of general symptoms, so the doctor directs the person to general clinical examinations.

What can be found in the general blood test? The level of blood neutrophils rises and the ESR (erythrocyte sedimentation rate) accelerates. You can already suspect brain damage. Along with this, there is a decrease in glucose in the blood test, and protein appears in the urine. But on the basis of only these tests, it is still difficult to conclude that there is any disease.

Other research methods help to finally determine the diagnosis.

The virological method for detecting tick-borne encephalitis is the detection or isolation of a virus from the blood or cerebrospinal fluid during the first week of illness, followed by infection of laboratory mice.
More accurate and faster serological blood tests RSK, ELISA, RPHA, take paired blood sera of a sick person with an interval of 2-3 weeks.

It is important to fully collect information about the development of the disease before starting the examination. Already at this stage, the diagnosis can be assumed.

Consequences of tick-borne encephalitis

Recovery from tick-borne encephalitis can be lengthy for several months.

The European form of the disease is an exception, the cure occurs quickly without minimal residual effects, but late initiation of treatment can complicate the disease and in 1-2% of cases leads to death.

As for other forms of the disease, the prognosis here is not so favorable. The fight against the consequences sometimes lasts from three weeks to four months.

The consequences of tick-borne encephalitis in humans include all kinds of neurological and psychiatric complications. They are observed in 10-20% of cases. For example, if during the course of the disease a person had a decrease in immunity, this will lead to persistent paresis and paralysis.

In practice, there were fulminant forms of tick-borne encephalitis, leading to fatal complications during the first days of the onset of the disease. The number of deaths ranges from 1 to 25% depending on the variant. The Far Eastern type of the disease is accompanied by the maximum number of irreversible consequences and deaths.

In addition to the severe course and unusual forms of the disease, there are complications of tick-borne encephalitis affecting other organs and systems:

pneumonia;
heart failure.

Sometimes there is a relapsing course of the disease.

Treatment

Tick-borne encephalitis is one of the most severe ailments, its course is not easy and is almost always accompanied by numerous symptoms. Treatment of tick-borne encephalitis is complicated by the lack of drugs that could affect the pathogen. That is, there are no specific drugs that can kill this virus.

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

use hormonal drugs or glucocorticosteroids as an anti-shock treatment for tick-borne encephalitis and to combat respiratory failure;
magnesium preparations and sedative drugs are prescribed to relieve seizures;
for detoxification, isotonic solution and glucose are used;
after the acute phase of tick-borne encephalitis subsides, B vitamins and antihistamines are used.

Human immunoglobulin is also used against tick-borne encephalitis. It is obtained from the blood plasma of donors. The timely administration of this medicine contributes to the mild course of the disease and a quick recovery.

Immunoglobulin is used according to the following scheme:

prescribe the drug from 3 to 12 ml during the first three days;
in the case of a severe course of the disease, immunoglobulin is used twice a day with an interval of 12 hours, 6-12 ml, after three days the drug is used only 1 time;
if the body temperature has risen again - the medicine is prescribed again in the same dose.

Disease prevention

Prevention of tick-borne encephalitis is nonspecific and specific. The first reduces the likelihood of contact with the carrier of the infection:

in order not to get infected with tick-borne encephalitis, you need to reduce the likelihood of ticks being sucked during walks in nature from April to June, that is, use repellents;
when working outdoors in the foci of the spread of infection, it is recommended to wear closed clothes even in the summer, to cover open areas of the body as much as possible;
after returning from the forest, you must carefully examine the clothes and ask someone close to examine the body;
a non-specific measure for the prevention of tick-borne encephalitis in one's own area is mowing tall grass in spring and summer, using chemicals to repel ticks.

What to do if a tick is found on the body after a walk? It is necessary to remove it as soon as possible, so the likelihood of the causative agent of the disease entering the human blood will decrease. It is recommended not to throw the insect away, but to bring it to the laboratory and analyze it for tick-borne encephalitis. In a hospital or paid laboratory, a blood-sucking insect is examined for the presence of a pathogen. The method of infecting laboratory animals with a virus isolated from a tick is used. Even a small fragment is enough to make a diagnosis. They also use a faster method of studying an insect - PCR diagnostics. If the presence of a pathogen in a tick is established, a person is urgently sent for emergency prevention of the disease.

There are two main ways to protect a person from the development of an ailment: in an emergency and in a planned manner.

Emergency prevention of tick-borne encephalitis is carried out after contact with a tick. It can be started even before the fact that the infection of the insect is established. Immunoglobulin is used in a standard dose - 3 ml for adults, and for children 1.5 ml intramuscularly. The drug is prescribed as a prophylactic treatment for encephalitis to all unvaccinated against infection. 10 days after the first dose, the drug is administered again, but in a double dose.
Planned specific prevention of tick-borne encephalitis is the use of a vaccine against the pathogen. It is used by everyone living in an area with high rates of morbidity. Vaccination can be done according to epidemic indications a month before the spring season of awakening ticks.

Scheduled to vaccinate against tick-borne encephalitis, not only residents of infected areas, but also visitors, in case of a business trip to a dangerous, from the point of view of morbidity, zone.

Today, there are two main options for vaccines: tissue-inactivated and live, but attenuated. They are used twice with repeated revaccination. But none of the available drugs protect against tick-borne encephalitis for a long time.

Is the tick-borne encephalitis virus dangerous today during the active development of the preventive branch of medicine? For many years, the causative agent of the disease will be classified as life-threatening. There are all the prerequisites for this - a huge number of animal carriers in nature, their distribution over a large area, the lack of specific treatment for all forms of the disease. From all this, only one correct conclusion follows - it is necessary to carry out timely prevention of tick-borne encephalitis through vaccination.