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Symptoms of tick-borne encephalitis after a tick bite. Symptoms and treatment of tick-borne encephalitis Tick-borne encephalitis symptoms in adults consequences

Tick-borne disease is a viral disease that is extremely severe and ends in paralysis or death. This disease affects the central nervous system and the brain, an inflammatory process develops in the substance of the brain - this can lead to disruption of the functioning of any of its parts.

Causes

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Most often, the viral disease in question is diagnosed in the spring and autumn periods of the year. And this is due to the activity of ticks - it is these insects, inhabitants of forests and fields, that are carriers of the disease. note: In different regions of Russia, the incidence of tick-borne encephalitis is different.
Tick-borne encephalitis refers to the primary type of disease - the effect of the virus is directly on the substance of the brain or spinal cord, no concomitant pathologies of infectious, inflammatory etiology are diagnosed.

Signs of tick-borne encephalitis

When infected with the tick-borne encephalitis virus, the symptoms of the pathology appear almost immediately - if, for example, the bite was committed in the morning, then by the evening the patient will show signs of severe intoxication of the body:

  • nausea and severe vomiting - it occurs regardless of how long ago and in what quantity a person took food;
  • a sharp increase in temperature to critical levels - no antipyretic drugs bring relief;
  • – intense, accompanied by pulsation and a feeling of compression of the skull;
  • the skin of the face and neck turns red.

After a short time, other signs of encephalitis begin to appear:

  • decreased blood pressure;
  • signs of inflammation at the site of the bite (swelling, redness, pain on palpation);
  • heart rhythm disturbances - arrhythmia, bradycardia, expressed in shortness of breath and chest pain;
  • rigidity of the neck muscles - they are extremely tense, the patient cannot hold his head straight, it is thrown back;
  • photophobia.

Important:If tick-borne encephalitis was detected at the very beginning of its development, then doctors always give a favorable prognosis. IN otherwise the person either dies or becomes disabled. Symptoms may vary depending on the form in which the disease in question develops. Initial period characterized by the presence of neurological disorders (dizziness, psycho-emotional disturbances, etc.), can result in complete recovery without complications and consequences or death of the patient. The next period may be accompanied by epileptic seizures, paresis and paralysis, numbness of the skin of the face and neck, and an increase in body temperature to 39-40 degrees. The doctor observes the degree of difference in neurological disorders and determines the type of tick-borne encephalitis:

  1. Feverish– the patient exhibits signs of general intoxication of the body, recovery occurs relatively quickly.
  2. Meningeal– occurs with fever and all the signs of meningococcal infection, even in the cerebrospinal fluid (cerebrospinal fluid) there is a meningococcal element and protein. The patient often experiences mental disorders of a reversible type - delusions, hallucinations, excessive agitation. The disease in this form has a favorable prognosis, but chronic paresis of the facial muscles may develop.
  3. Meningoencephalitic– characterized by a violation of the facial expression (eyelids and corners of the eyes droop, the face warps), loss of sonority of the voice, and disruption of the speech apparatus. The meningoencephalitic type of the disease in question is characterized by a wave course of hyperthermia (increased body temperature). The first wave lasts 2 weeks and is accompanied only by signs of intoxication, the second occurs 2-3 days after the end of the first, is accompanied by symptoms of meningitis and lasts 3 weeks. The prognosis is favorable.
  4. Poliomyelitis– during the first 2 days, patients complain only of fatigue and muscle pain. Then a disorder develops motor functions, regular muscle twitching, paresis in the shoulder and cervical regions spine, head hanging down on the chest. This type of tick-borne encephalitis has variable prognoses, because 2-3 weeks after recovery, atrophy of the affected muscles becomes obvious in the patient - it can be reversible (the patient recovers completely) and irreversible (disablement threatens).
  5. Polyradiculoneuritis– the roots of the peripheral and frontal nerves are affected by a viral infection, the limbs become insensitive to external stimuli.

More information about the symptoms of tick-borne encephalitis and the forms of the disease is described in the video review:

Diagnosis of tick-borne encephalitis

A preliminary diagnosis is made by a doctor during the initial examination of the patient - complaints of headache, fever, convulsions muscle tissue, confirmation of the patient’s presence in a forest/park area several days before the onset of symptoms confirms the suspicion of the onset of the disease in question. But no specialist can make a diagnosis without additional examinations:

  • computer – allows the doctor to see the inflammatory process in the brain, assess its prevalence and severity;
  • collection for laboratory testing of cerebrospinal fluid ( cerebrospinal fluid) – the presence of protein in it and an increased content of leukocytes are detected;
  • blood chemistry.

Treatment methods

If tick-borne encephalitis was detected on early stage development, then anti-encephalitis immunoglobulin therapy will be effective. For a successful recovery, the patient is given an inactivated vaccine and ribonucleic acid. Note:Such vaccination can also be carried out for preventive purposes - this helps to avoid infection with the disease in question. viral disease and reduce intoxication symptoms inflammatory process. It is recommended to vaccinate in the spring and autumn periods - the peak of patient requests regarding the development of typical symptoms of tick-borne encephalitis.

General principles of therapeutic interventions

A patient diagnosed with tick-borne encephalitis must observe strict bed rest throughout the acute period of the disease - this significantly alleviates the patient’s condition. In addition, doctors may prescribe:

  • antibacterial drugs (antibiotics) - their administration is especially important in the development of the meningeal form of the disease in question;
  • antiviral agents;
  • vitamins B and C;

It is important to carry out symptomatic therapy in a timely manner - for example, if the body temperature rises, prescribe antipyretic drugs, if intense pain occurs, non-steroidal anti-inflammatory drugs or analgesics. Only after 3 weeks, and in case of complete stabilization of the patient’s condition, discharge is possible. The rehabilitation period is very long - the patient must visit a therapist once every 2 months, and a neurologist once a month. Mud therapy and sanatorium-resort treatment are useful.

ethnoscience

A tick that has already burrowed into the skin and is feeding on human blood is easy to detect (especially a female), but it is almost impossible to pull it out on your own.

All traditional methods getting rid of embedded ticks (dripping vegetable oil, wrapping it with thread) are absolutely useless - infection with tick-borne encephalitis occurs when the insect bites through human skin.


Important:Traditional methods of treating the disease in question are aimed at strengthening the body and getting rid of headaches; they are appropriate to use at the recovery stage. It is strictly forbidden to take any therapeutic measures if symptoms of tick-borne encephalitis develop without consulting a doctor - this can lead to rapid development of the disease and death. To speed up the recovery period, it is recommended to use the following products from the category ethnoscience:

  1. , lemon balm, periwinkle. These herbs cannot be mixed in one decoction - they lose their medicinal properties. You need to separately prepare a decoction of mint/lemon balm/periwinkle according to one recipe: 1 tablespoon of the dry ingredient per glass of water, boil for 5 minutes, leave for 15 minutes, strain. Directions for use: ½ cup of mint decoction in the morning, the same amount of periwinkle decoction at lunchtime and 1/3 cup of lemon balm decoction at night. Duration of treatment – ​​2 weeks.
  2. Poplar black. You need to use the seeds of this plant (sold in pharmacies) in the amount of 1 teaspoon per glass of boiling water. The medicine is brewed like regular tea, taken a tablespoon before meals 3-5 times a day. An infusion of black poplar seeds perfectly relieves attacks of nausea and relieves constant headaches.
  3. Melissa officinalis. You need to take 2-3 tablespoons of the dry component and brew it in a thermos like tea (per 1 liter of boiling water). After 30 minutes of infusion, the medicine is ready for use - you need to drink it instead of regular tea to relieve spasms in muscle tissue and get rid of dizziness.
  4. Periwinkle in alcohol. For 1 liter of medical alcohol you need to take 100 g of dry periwinkle, mix everything and leave for 20 days in a dark and warm place. Then take 10 drops in the morning and evening for 5 months. For better perception of the medicine (it does not have an exquisite taste), alcohol drops can be diluted in a small amount of water. Periwinkle in alcohol improves blood circulation, normalizes and stabilizes blood pressure, cleanses blood vessels, and improves oxygen supply to the brain.

Prevention of tick-borne encephalitis

Ticks very rarely live in urban environments; they usually feel comfortable in forests, fields and meadows, and in damp and dark places. Most often, patients present with signs of tick-borne encephalitis after hiking or nature picnics. To avoid tick bites, you must follow simple rules being in nature:

  • clothing must have long sleeves and long legs;
  • you need to tuck your pants into your socks, and it is advisable to wear gloves on your palms (even if they are very thin), into which the sleeves are tucked;
  • anti-tick agents should be applied to clothing - for example, DEET-34 paste has been considered the most effective means of preventing/protecting against tick bites for many years;
  • 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.

Important: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. To get more information about preventing tick-borne encephalitis and find out which tick protection measures are the most effective, watch this video review:

Tick-borne encephalitis is a rather dangerous disease, which in 84% of cases leads to death. But if you seek medical help in a timely manner, this figure decreases by 8-9 times, so carefully monitor the clinical picture. If you have recently returned from a hike or a picnic, then within the first 24 hours the first symptoms of developing tick-borne encephalitis may appear - this is an absolute reason to seek professional help. Tsygankova Yana Aleksandrovna, medical observer, therapist of the highest qualification category.

A natural focal viral infectious disease with a transmissible pathogen transmission mechanism, characterized by fever and predominant damage to the central nervous system.

Clinical classification of tick-borne encephalitis
Highlight5 clinical forms:
· febrile;
· meningeal;
· meningoencephalitic;
· meningoencephalopoliomyelitis (poliomyelitis);
· polyradiculoneuritic.

By severity:
· light;
· medium-heavy;
· heavy.

With the flow:
· acute;
· chronic (progressive);
· two-wave flow indicating the shape of the second wave.

All clinical manifest forms are divided into focal and non-focal.

Non-focal ones include:
· febrile form;
· meningeal form.

To focal:
· meningoencephalitic;
· meningoencephalopoliomyelitis;
· polyradiculoneuritic.

Classification of chronic (progressive) forms of tick-borne viral encephalitis:
Clinical form:
· hyperkinetic (syndromes: Kozhevnikov epilepsy, myoclonus-epilepsy, hyperkinetic);
· amyotrophic (syndromes: poliomyelitis, encephalopoliomyelitis, multiple encephalomyelitis, amyotrophic lateral sclerosis);
· rare syndromes not related to forms 1 and 2.

By severity:
· mild (ability to work is preserved);
· average (disability group 3);
· severe (disability of 1st and 2nd groups).

According to the time of occurrence of the chronic process:
· initial progressive (direct continuation of acute CE);
· early progressive (occurs during the first year after acute TE);
· late progressive (occurs a year or more after acute TE);
· spontaneous progressive (occurs without clear acute CE).

According to the nature of the course of chronic FE:
· recurrent;
· continuously progressing;
· abortifacient.

By stages of the disease:
· initial;
· increase (progression);
· stabilization;
· terminal.

By development time:
· primary progressive form (first identified in the absence of a history of any acute form of CE);
· secondary progressive form (as a direct continuation of any acute form of FE, or developed in a later period after the manifest stage).

Complications:
With all the above-described clinical forms of tick-borne encephalitis, epileptiform, hyperkinetic syndromes and other signs of damage can be observed nervous system.

Outcomes:
· recovery;
· residual (residual) phenomena;
lethal
· transition to a chronic (progressive) course.

Residual (residual) phenomena
· flaccid paresis of the cervicobrachial (cervicothoracic) localization, arms, legs;
· atrophy of the affected muscles;
· decreased intelligence;
epilepsy.

Examples of diagnosis formulation:
Tick-borne viral encephalitis, febrile form, moderate severity, acute course (IgM ELISA to the TBE virus - positive).
Tick-borne viral encephalitis, meningoencephalitic form, severe severity, acute course (PCR RNA of the TBE virus is positive).
Complication: epileptiform syndrome.

ETIOLOGY

Tick-borne encephalitis virus belongs to the family Flaviviridae. The virus, 45–50 nm in size, consists of a nucleocapsid with cubic symmetry and is coated with an envelope. The nucleocapsid contains RNA and protein C ( core). The shell consists of two glycoproteins (membrane M, shell E) and lipids. Based on homology analysis of the gene fragment encoding the E protein, five main genotypes of the virus are distinguished:

G genotype 1 - Far Eastern variant;

G genotype 2 - Western (Central European) variant;

G genotype 3 - Greek-Turkish variant;

G genotype 4 - East Siberian variant;

G genotype 5 - Ural-Siberian variant.

Genotype 5 is the most common, found throughout most of the range of the tick-borne encephalitis virus.

The virus is cultivated in chicken embryos and tissue cultures of various origins. With prolonged passaging, the pathogenicity of the virus decreases.

Among laboratory animals, the most sensitive to infection with the virus are white mice, suckling rats, hamsters and monkeys; among domestic animals - sheep, goats, pigs, horses. The virus is resistant to various environmental factors to varying degrees: when boiled, it dies within 2–3 minutes, is easily destroyed during pasteurization, treatment with solvents and disinfectants, but is able to remain viable for a long time under low temperatures, in a dried state. The virus persists for a long time in foods such as milk or butter, which can sometimes be sources of infection. The virus is resistant to low concentrations of hydrochloric acid,

therefore, a food route of infection is possible.

EPIDE MYOLOGY

Tick-borne encephalitis is a natural focal disease. Strains of the Central European variant are distributed in Europe to the territory of Siberia. Beyond the Ural Range, the Ural-Siberian and East Siberian genotypes of the virus predominate; in the Far East, the Far Eastern variant predominates. The genetic diversity of the pathogen is apparently associated with differences in the clinical picture of tick-borne encephalitis in Europe, Siberia and the Far East.

The main reservoir and carrier of the virus in nature is ixodid ticks Ixodes persulcatus, xodes ricinus with transphase (larva–nymph–imago) and transovarial transmission of the pathogen. Additional reservoirs of the virus are rodents (chipmunk, field mouse), hares, hedgehogs, birds (thrush, goldfinch, tap dancer, finch), predators (wolf, bear), large wild animals (elk, deer). Some farm animals are also susceptible to the tick-borne encephalitis virus, among which goats are the most sensitive. Due to the fact that the range of reservoir hosts is quite wide, the virus continues to circulate in nature.

The tick becomes infected with the virus when biting mammals that are in the viremic phase. The main route of human infection is vector-borne transmission through tick bites. The risk of infection in humans is closely related to tick activity. The seasonal peak of this activity depends on the climatic characteristics of geographic regions, but is maximum in the spring and summer (from April to August). People aged 20–60 years are most often affected. Urban residents currently predominate in the structure of cases. It is also possible to transmit the virus through nutritional means (when eating raw milk from goats and cows), as well as as a result of crushing a tick when removing it from the human body and, finally, by aerosol

by violating working conditions in laboratories.

Susceptibility to tick-borne encephalitis is high, regardless of gender and age, especially among people visiting a natural outbreak for the first time. The indigenous people are dominated by sub clinical forms infections (one clinical case per 60 inpatients).

Immunity after tick-borne encephalitis is persistent and lifelong.

Virus-neutralizing antibodies remain in the blood of those who have recovered throughout their lives.

The patient is not dangerous to others as a source of infection.

Prevention measures

Preventive measures can be divided into two main groups: nonspecific and specific.

Nonspecific prevention

Nonspecific prevention is associated with protecting humans from tick attacks. Public prevention aimed at destroying or reducing the number of ticks. Personal prevention measures include the use of specially selected clothing when visiting the forest, the use of various repellents, and mutual examinations after visiting the forest and parks within the city.

Specific prevention

Specific prevention includes active and passive immunization of the population. Vaccination is carried out with a tissue culture vaccine (triple vaccinations), followed by revaccination after 4, 6 and 12 months.

Specific seroprophylaxis is carried out with homologous donor immunoglobulin as pre-exposure (before the expected tick bite,

when entering a risk zone) and post-exposure (after a tick bite).

Immunoglobulin is administered intramuscularly at a rate of 0.1 ml/kg once a few hours before entering the forest area or during the first day after a tick bite. In the next 2–3 days, the effectiveness of post-exposure immunoprophylaxis decreases.

In unvaccinated patients, paralytic forms are much more common, the percentage of residual effects and mortality are higher. Severe forms are 4 times more common among unvaccinated people than among vaccinated people.

PATHOGENESIS

After introduction, the virus multiplies locally in skin cells. At the site of the bite, degenerative-inflammatory changes develop in the tissues. In the alimentary route of infection, virus fixation occurs in the epithelial cells of the gastrointestinal tract.

The first wave of viremia (transient) is caused by the penetration of the virus into the blood from the sites of primary localization. At the end incubation period a second wave of viremia occurs, coinciding with the start of virus replication in internal organs. The final phase is the introduction and replication of the virus in the cells of the central nervous system and peripheral nervous system.

“Plus-strand” RNA of the tick-borne encephalitis virus is capable of directly translating genetic information to the ribosomes of a sensitive cell, i.e. perform the functions of mRNA.

The tick-borne encephalitis virus in the central nervous system primarily affects the gray matter, as a result of which polioencephalitis develops. The observed lesions are nonspecific and include cellular inflammation, hyperplasia, glial proliferation, and neuronal necrosis.

Progressive forms of tick-borne encephalitis are associated with long-term persistence of the virus in active form in the cells of the central nervous system. Mutant forms of the virus play a significant role in the development of persistent infection.

CLINICAL PICTURE

The incubation period for infection through a tick bite is 5–25 (on average 7–14) days, and for foodborne infection - 2–3 days.

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:

G inapparent (subclinical);

G feverish;

G meningeal;

G meningoencephalitic;

G polio;

G polyradiculoneuritic.

The course of tick-borne encephalitis can be mild, mild, moderate or severe.

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

Main symptoms and dynamics of their development

The disease, regardless of its form, in the vast majority of cases begins acutely. Rarely there is a period of prodrome lasting 1–3 days.

Feverish form tick-borne encephalitis is registered in 40–50% of cases.

In most patients, the disease begins acutely. The febrile period lasts from several hours to 5–6 days. During the acute period of the disease, body temperature rises to 38–40 °C and higher. Sometimes two-wave and even three-wave fever is observed.

Patients experience anxiety of varying intensity headache, general weakness, malaise, chills, feeling hot, sweating, dizziness, pain in eyeballs ah and photophobia, loss of appetite, pain in the muscles, bones, spine, in the upper and lower limbs, in the lower back, neck and joints. Nausea is common and vomiting is possible for one or several days. Injection of the vessels of the sclera and conjunctiva, hyperemia of the face, neck and upper half of the body, severe hyperemia of the mucous membranes and oropharynx are also noted. In some cases, pale skin is noted. Phenomena of meningism are possible. In this case, there are no inflammatory changes in the CSF.

In most cases, the disease ends in complete clinical recovery. However, in a number of patients, asthenovegetative syndrome persists after discharge from the hospital.

Meningeal form- the most common form of tick-borne encephalitis. In the morbidity structure, it is 50–60%. The clinical picture is characterized by pronounced general infectious and meningeal symptoms.

In most cases, the onset of the disease is acute. Body temperature rises to high values. Fever is accompanied by chills, a feeling of heat and sweating. Headaches of varying intensity and localization are typical. Anorexia, nausea and frequent vomiting are noted. In some cases, myasthenia gravis, pain in the eyeballs, photophobia, unsteady gait and hand tremors are expressed.

On examination, hyperemia of the face, neck and upper body, injection of blood vessels in the sclera and conjunctiva are revealed.

Meningeal syndrome upon admission is found in half of the patients.

In the rest, it develops on the 1st–5th day of hospital stay. Transient disorders caused by intracranial hypertension are identified; facial asymmetry, anisocoria, failure to bring the eyeballs outward, nystagmus, increased or depressed tendon reflexes, anisoreflexia.

CSF pressure is usually elevated (250–300 mmH2O). Pleocytosis ranges from several tens to several hundred cells in 1 μl of CSF.

Lymphocytes predominate; in the early stages, neutrophils may predominate.

Asthenovegetative syndrome persists longer than with the febrile form. Characterized by irritability and tearfulness. The benign course of the meningeal form of tick-borne encephalitis does not exclude the possibility of further development clinical picture chronic form of the disease.

Meningoencephalitic form characterized by a severe course and high mortality. The frequency of this form in certain geographic regions is from 5 to 15%. The acute period of the disease is characterized by heat, more severe intoxication, severe meningeal and cerebral symptoms, as well as signs of focal brain damage.

Characterized by deep disturbances of consciousness up to the development of coma. In patients admitted in an unconscious and stuporous state, motor agitation, convulsive syndrome, muscle dystonia, fibrillary and fascicular twitching in individual muscle groups are observed. Nystagmus is often detected. The appearance of subcortical hyperkinesis, hemiparesis, as well as lesions is characteristic cranial nerves: III, IV, V, VI pairs, somewhat more often VII, IX, X, XI and XII pairs.

With brainstem lesions, bulbar and bulbopontine syndromes appear, and less commonly, symptoms of midbrain damage. Violations noted

swallowing, choking, nasal tone of voice or aphonia, paralysis of the muscles of the tongue, when the process spreads to the bridge - symptoms of damage to the nuclei of the VII and VI cranial nerves. Mild pyramidal signs, increased reflexes, clonus, and pathological reflexes are often detected. Lesions of the brain stem are extremely dangerous due to the possible development of respiratory and cardiac problems. Bulbar disorders are one of the main causes of high mortality in the meningoencephalitic form of tick-borne encephalitis.

When examining the CSF, lymphocytic pleocytosis is detected.

Protein concentration increased to 0.6–1.6 g/l.

Hemiplegia among focal lesions The nervous system occupies a special place.

In the first days of the febrile period (more often in older people), hemiplegia syndrome develops of a central type, reminiscent of vascular lesions of the nervous system (stroke) in its course and location. These disorders are often unstable and already in the early period have a tendency to reverse development.

Asthenovegetative syndrome develops in 27.3–40.0% of patients. Residual effects include paresis of the facial nerves.

Poliomyelitis form- the most severe form of infection. Most common in previous years, it is currently observed in 1–2% of patients.

With this form, the disability of patients is high.

The neurological status is characterized by significant polymorphism.

Patients with polio may suddenly develop weakness or numbness in a limb. Subsequently, motor disorders develop in these limbs. Against the background of fever and cerebral symptoms, flaccid paresis of the cervicobrachial muscles and upper limbs. Often paresis is symmetrical and covers the entire musculature of the neck. The raised hand falls passively, the head hangs on the chest. Tendon reflexes are not evoked. At the end of the second week, atrophy of the affected muscles develops. Paresis and paralysis of the lower extremities are rare.

The course of the disease is always severe. Improvement in general condition occurs slowly. Only half of the patients experience moderate recovery of lost functions. In the CSF, pleocytosis is detected from several hundred to thousands of cells in 1 μl.

Residual effects in the polio form are characteristic of all patients. There is weakness in the muscles of the neck and upper limbs, a symptom of a “dangling” head, paresis of the muscles of the upper limbs, wasting of the neck muscles, shoulder girdle, forearms, intercostal muscles.

Polyradiculoneuritic form diagnosed in 1–3% of patients. The leading symptoms are mononeuritis (facial and sciatic nerves), cervicobrachial radiculoneuritis, as well as polyradiculoneuritis with or without an ascending course. The clinical picture is dominated by neuralgia, radicular symptoms, muscle and nerve pain, peripheral paralysis or paresis. Patients experience pain along the nerve trunks, paresthesia (feeling of “crawling goosebumps”, tingling).

Two-wave fever occurs in all forms of the disease, but more often in the meningeal form. This type of fever is more typical for diseases caused by the Central European and East Siberian genotypes of the virus. For the first febrile wave, the presence of a pronounced infectious-toxic syndrome is required. There is an acute onset, a sudden increase in temperature to 38–39 °C, accompanied by headache and general weakness. After 5–7 days, the patients’ condition improves, body temperature returns to normal, but after a few days it rises again. Often, against the background of the second wave, meningeal syndrome appears in patients.

Chronic progressive course observed in 1–3% of patients. Chronic forms occur several months and sometimes years after the acute period of the disease, mainly with meningoencephalitic, less often meningeal forms of the disease.

The main clinical form of the chronic period is Kozhevnikov epilepsy, which is expressed in constant myoclonic hyperkinesis, affecting primarily the muscles of the face, neck, and shoulder girdle. Periodically, especially during emotional stress, there is a paroxysmal intensification and generalization of myoclonus or its transition into a large tonic-clonic attack with loss of consciousness. There is also a syndrome of chronic subacute poliomyelitis caused by slowly progressive degeneration of peripheral motor neurons of the anterior horns of the spinal cord, which is clinically characterized by increasing atrophic paresis of the limbs, in

mainly upper, with a constant decrease in muscle tone and tendon reflexes.

Hyperkinetic syndrome is characterized by the appearance of spontaneous rhythmic muscle contractions in individual muscle groups of paretic limbs already in the acute period of the disease. Often progressive forms are accompanied by mental disorders up to dementia. Often clinical symptoms are mixed, when the progression of hyperkinesis is combined with increasing amyotrophy and, sometimes, mental disorders.

As the severity of symptoms increases, patients become disabled.

In recent years, severe clinical forms of the acute period have been observed relatively rarely, which does not exclude the further development of a chronic progressive form of the disease.

Mortality and causes of death

Mortality in tick-borne encephalitis is associated with the development of bulbar and convulsive-comatous syndromes. The frequency of deaths depends on the genotype of the circulating virus and varies from isolated cases in Europe and the European part of Russia to 10% in the Far East.

DIAGNOSTICS

The diagnosis is based on anamnestic, clinical, epidemiological and laboratory data. In endemic regions, great importance is attached to visiting a forest, park, or cottage in the spring and summer, the fact of tick suction, as well as eating unboiled goat or cow milk.

Clinical diagnosis

Early clinical diagnostic signs diseases - increased body temperature to 39–40 °C, chills, headache, dizziness, nausea, vomiting, general weakness, pain in muscles, joints, and lower back.

During examination, attention is paid to the presence of hyperemia of the face, neck and upper torso, injection of scleral vessels, conjunctivitis and hyperemia of the oropharynx.

The patients are lethargic and adynamic. Must be carefully inspected skin, since spots or hyperemic spots of various sizes may remain at the site of tick suction. The neurological status of all patients must be examined.

Specific and nonspecific laboratory diagnostics

In the peripheral blood, moderate lymphocytic leukocytosis is detected, sometimes a shift to the left with an increase in the number of band leukocytes, increase in ESR.

With a two-wave course of the disease, in the first wave most patients experience leukopenia with relative lymphocytosis, during the second wave - leukocytosis with a neutrophil shift and an increase in ESR. In meningeal and focal forms of the disease, lymphocytic pleocytosis is detected in the CSF, from several tens to several hundred cells in 1 μl.

Laboratory diagnosis of tick-borne encephalitis is based on the detection of antibodies in the blood of patients. They use RSK, RTGA, RN and other methods.

Diagnostic standard

The diagnostic standard is ELISA, which allows you to separately determine the total pool of antibodies to the virus, immunoglobulins of class G and M. Determination of immunoglobulins of class M is important for diagnosing not only acute cases of the disease, but also exacerbations of the chronic course. Immunoglobulins class G - a consequence of a previous disease or effective vaccination. Serological studies are carried out in paired sera taken at the beginning and end of the disease.

In the absence of antibodies, it is possible to study a 3rd blood sample taken 1.5–2 months after the onset of the disease.

In recent years in clinical practice are introducing the PCR method, which makes it possible to detect specific fragments of the virus genome in the blood and CSF on early stages diseases. The method makes it possible to make a diagnosis within 6–8 hours.

Differential diagnosis

Differential diagnosis of tick-borne encephalitis is carried out with three

main groups of diseases:

G other vector-borne infections carried by ixodid ticks;

G infectious diseases with acute onset and pronounced general infectious manifestations;

G other neuroinfections.

In regions where tick-borne encephalitis is endemic, other vector-borne infections usually occur: systemic tick-borne borreliosis and tick-borne rickettsiosis. What these infections have in common is a history of a tick bite, approximately the same incubation periods, and the presence of symptoms of intoxication in the acute period.

Simultaneous infection (from 0.5 to 5–10%) with pathogens of tick-borne encephalitis and tick borrelia I. persulcatus determines the existence of conjugate natural foci of these infections and the possibility of developing signs of both diseases in one patient, i.e. mixed infections. To make a diagnosis of mixed infection, the presence of clinical signs two infections.

The diagnosis of tick-borne encephalitis is based on the characteristic clinical picture of the disease and the detection of IgM in the blood serum or an increase in IgG titers to the tick-borne encephalitis virus. Diagnosis tick-borne borreliosis based on the clinical picture (erythema migrans, Bannwart syndrome, neuritis facial nerve, polyradiculoneuropathy, myocarditis, polyarthritis) and determination of diagnostic IgM titers in blood serum Borrelia burgdorferi or an increase in IgG titers during ELISA.

When differentially diagnosing tick-borne encephalitis with influenza, it is necessary to take into account the seasonality of the disease, visiting the forest, the presence of contact with ticks or the fact of hypothermia, as well as the results of laboratory tests. HFRS is distinguished from tick-borne encephalitis by excruciating pain in the lumbar region, pronounced changes in clinical analysis blood (from the 3rd–5th day of illness, neutrophilic leukocytosis, shift leukocyte formula to the left, the appearance of plasma cells, an increase in ESR to 40–60 mm/h) and the development of renal failure, characterized by oliguria, low relative density of urine, proteinuria.

When conducting differential diagnosis meningeal forms of tick-borne encephalitis with meningitis caused by other viruses (Coxsackie viruses, ECHO, mumps, influenza, herpes viruses), first of all, it is necessary to pay attention to the seasonality of the disease and a history of visiting the forest, bites and attacks by ticks. Along with the clinical symptoms of the disease, methods of virological and serological testing of blood serum are of great importance.

Tuberculous meningitis is characterized by a prodromal period, gradual development meningeal symptoms with the involvement of cranial nerves in the process. As meningeal symptoms increase, lethargy and adynamia increase, patients gradually fall into a soporous state. Excitement is rare. The headache is severe. CSF leaks under high pressure; lymphocytic pleocytosis; protein content is increased, glucose content is decreased.

The formation of a delicate film in the CSF is typical, sometimes with the presence of Mycobacterium tuberculosis, which finally clarifies the diagnosis. During X-ray examination, various changes in the lungs of a tuberculous nature are often observed. A history of tuberculosis is often found in the patient himself or in his environment.

An example of a diagnosis formulation

A84.0. Tick-borne encephalitis, meningeal form, moderate severity (CSF PCR positive).

Indications for hospitalization

All patients with suspected tick-borne encephalitis must be hospitalized in a specialized infectious diseases department with an intensive care unit.

Mode. Diet

Strict bed rest is indicated, regardless of the general condition and well-being, during the entire febrile period and 7 days after the temperature normalizes. No special diet required (common table). During the febrile period, drinking plenty of fluids is recommended: fruit drinks, juices, bicarbonate mineral waters.

Drug therapy

Etiotropic treatment is prescribed to all patients with tick-borne encephalitis, regardless of previous vaccination or prophylactic use of anti-encephalitis immunoglobulin.

Depending on the form of the disease, immunoglobulin against tick-borne encephalitis is administered intramuscularly in the following doses.

  • For patients with a febrile form: daily in a single dose of 0.1 ml/kg, for 3–5 days until the general infectious symptoms resolve (improvement in general condition, disappearance of fever). The course dose for adults is at least 21 ml of the drug.
  • For patients with the meningeal form: daily in a single dose of 0.1 ml/kg 2 times a day with an interval of 10–12 hours for at least 5 days until the patient’s general condition improves. The course average dose is 70–130 ml.
  • For patients with focal forms: daily in a single dose of 0.1 ml/kg 2–3 times a day at intervals of 8–12 hours for at least 5–6 days until the temperature decreases and stabilizes neurological symptoms. The average course dose for an adult is at least 80–150 ml of immunoglobulin.
  • In case of extremely severe disease, the single dose of the drug can be increased to 0.15 ml/kg.

The effectiveness of the use of interferon alpha-2 drugs and endogenous interferon inducers in the acute period has not been sufficiently studied.

Ribonuclease is prescribed intramuscularly at 30 mg every 4 hours for 5 days.

Nonspecific therapeutic measures are aimed at combating general intoxication, cerebral edema, intracranial hypertension, and bulbar disorders. Dehydrating agents (loop diuretics, mannitol), 5% glucose solution, polyionic solutions are recommended; for respiratory disorders - mechanical ventilation, oxygen inhalation; to reduce acidosis - 4% sodium bicarbonate solution. For meningoencephalitic, poliomyelitis and polyradiculoneuritic forms of the disease, glucocorticoids are prescribed.

Prednisolone is used in tablets at the rate of 1.5–2 mg/kg per day in equal doses in 4–6 doses for 5–6 days, then the dose is gradually reduced by 5 mg every 3 days (course of treatment is 10–14 days). For bulbar disorders and disorders of consciousness, prednisolone is administered parenterally. For convulsive syndrome, anticonvulsants are prescribed: phenobarbital, primidone, benzobarbital, valproic acid, diazepam. In severe cases, antibacterial therapy is carried out to prevent bacterial complications.

Protease inhibitors are used: aprotinin. The chronic form of tick-borne encephalitis is difficult to treat, effectiveness specific means significantly lower than in the acute period. General restorative therapy and short courses of glucocorticoids (up to 2 weeks) at the rate of prednisolone 1.5 mg/kg are recommended. Among the anticonvulsant drugs used for Kozhevnikov epilepsy, benzobarbital, phenobarbital, and primidone are used. It is advisable to prescribe vitamins, especially group B, for peripheral paralysis - anticholinesterase drugs (neostigmine methyl sulfate, ambenonium chloride, pyridostigmine bromide).

Pathogenetic therapy
Detoxification therapy(the amount of fluid should be strictly controlled based on daily diuresis, blood acid-base level, volume of injected fluid, taking into account the degree of severity):
· with moderate severity of the infectious process, patients should drink plenty of fluids at the rate of 20-40 ml/kg.
· in case of severe infection - parenteral administration of isotonic solutions (under the control of blood electrolytes. The daily requirement is distributed in a minimum volume of only necessary drugs):
· 0.9% sodium chloride solution, 400 ml IV, drip [UD-S];
· 0.5% dextrose solution, 400.0 ml IV, drip [UD-S].

Dehydration therapy(for intracranial hypertension, prevention of cerebral edema):
· L-Lysine – escinate 5-10 ml 2 times a day intravenously [UD – V]
MgSO4 5.0-10.0 ml i.v.

Treatment of cerebral edema:
· mannitol 15% solution 1-1.5 g/kgv/v slowly in a stream or drip. The daily dose should not exceed 140-180 g with furosemide 20-40 mg (2-4 ml) IV.
· and/or L-lysine escinate 5-10 ml x 2 times a day for 3-5 days (UD – B]
under the control of blood Na+ content. When the blood Na+ content is at the level upper limit norms and above, the administration of mannitol is contraindicated due to changes in blood osmolarity and the threat of swelling of brain cells. In these cases, the administration of a concentrated glucose solution of 10%, 20% or 40% and a 0.45% NaCl solution is indicated.

Nonsteroidal anti-inflammatory drugs ( when body temperature rises above 38.5 0 C, in the presence of a head injury and a history of convulsive syndrome).
Duration 1-3 days:
Diclofenac 3 ml IM [UD – B]
or
Ketoprofen 2 ml IM [UD – B]
· paracetamol 500 mg, orally, at intervals of at least 4 hours [UD – B].
With severe pain syndrome (severe headache, muscle pain, bone aches, polyradiculoneuritis)
Tramadol 50–100 mg IV, IM, s.c. The maximum daily dose is 400 mg (in exceptional cases it can be increased to 600 mg). [UD – B]
or
· xefocam 8 mg intravenously in 200 ml of saline or as a bolus.

Glucocorticosteroids:
For meningoencephalitic, meningoencephalopoliomyelitis, polyradiculoneuritic forms and the development of ITS for 3-7 days, prednisolone 5-10 mg/kg, IV [UD – B]
or
dexamethasone 8-12 mg IV, bolus [UD – B]

Antihistamines:
clemastine 1ml, IM [UD – V]
or
Diphenhydramine 1% -1.0 with analgin 50% -2.0, IM

To improve microcirculation and rheological properties of blood, for antiplatelet purposes(taking into account coagulogram indicators):
· pentoxifylline 2% solution 100 mg/5 ml, 100 mg in 20-50 ml of 0.9% sodium chloride, IV drop, course from 10 days to 1 month [UD – B]
or
Heparin subcutaneously (every 6 hours) 50-100 IU/kg/day 5-7 days [LE – A]
or
warfarin 2.5-5 mg/day, orally

Symptomatic therapy:
Relief of convulsive syndrome:
· diazepam 2 ml per 10.0 ml 0.9% sodium chloride, IV bolus [UD – V]
or
carbamazepine 200 mg for seizures, as prescribed by a neurologist (from 200 mg to 600 mg) [UD – B]

Improving cerebral circulation:
In the acute period, with depression of consciousness and fever, vascular drugs are contraindicated, after normalization of temperature and clarity of consciousness, as well as in the presence of cognitive disorders, add antioxidants (if at the time of examination and there is no history of epileptic seizures):
Mexidol 5.0 IV drip per 200.0 ml 0.9% sodium chloride [UD – B],
· Ceraxon 500 mg-1000 mg intravenously in 200.0 ml of 0.9% sodium chloride [UD – B],
· gliatillin 1000 mg IV drip [UD – B]

Neuroprotection:
· ascorbic acid in the acute period 5.0–8.0 IV drops of 0.9% sodium chloride [UD – V]
· thiamine chloride 1.0-2.0 w/m [UD – V]
· pyridoxine hydrochloride 1.0-2.0 v/m [UD – V]

Antibacterial drugs (for severe forms of tick-borne encephalitis, complicated by the addition of a bacterial infection):
ceftriaxone 1.0 - 2.0g x 2 times/day, IM, IV, 10 days;
or
cefepime 1.0 g every 12 hours (i.m., i.v.). [UD – V]
· ciprofloxacin 100ml x 2 times/day, IV 7-10 days

Reserve antibacterial drugs:
· amikacin 15 mg/kg/day, IM, but not more than 1.5 g/day for 10 days. [UD – V]
Vancomycin 1.0 g every 12 hours, intravenously, for 7-10 days. [UD – V]
Meropenem 2.0 g every 8 hours IV, for 7-10 days [LE – B]

Combination of 2 or more antibacterial drugs according to indications:
Antifungal drugs ( according to indications ):
· Fluconazole 100 ml IV once a day, every other day, 3-5 times [UD – B]

Other drugs for general anesthesia during emergency medical care, intubation and other invasive measures:
· Propofol at a rate of 0.3–4 mg/kg per 1 hour IV drip to provide sedation during intensive care and during mechanical ventilation [LE – B]
or
Lidocaine 1%, 2% 4-5 ml

For infectious-toxic shock:
Prednisolone 5-10 mg/kg IV [UD – B]
· dopamine 10–15 mcg/kg per 1 min. i.v. The infusion is carried out continuously for from 2–3 hours to 1–4 days or more. The daily dose reaches 400–800 mg. The administration is carried out under ECG control. [UD – V]

With the development of respiratory failure:
· Mechanical ventilation from the moment the first signs of respiratory failure and edema and brain swelling appear, tracheostomy (if indicated).
· To combat hypoxia, systematically administer humidified oxygen through nasal catheters (20-30 minutes every hour).
· Conducting hyperbaric oxygenation (10 sessions under pressure p 02-0.25 MPa)

For bulbar disorders:
· IVL;
· Prozerin 1.0 ml s.c.

If hemostasis is impaired:
· FFP – according to indications;
· aprotinin 20-60 thousand. units bolus every 6 hours.

List of main medicines:
· human serum immunoglobulin against tick-borne encephalitis virus - solution for injection, 1 ml in an ampoule.

Additional treatments

In the acute period exclude physical exercise, balneotherapy, exercise therapy, massive electrical procedures. Sanatorium-resort treatment is carried out no earlier than 3–6 months after discharge from the hospital in climatic and restorative sanatoriums.

Everyone is afraid of tick bites, because everyone knows about the possible dangerous consequences of such a short-term encounter with a blood-sucking insect. In addition to the 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 kind of infection is this - tick-borne encephalitis virus? How does the disease caused by it manifest itself? Is it possible to cure this disease and what complications threaten the patient? What does the prevention of tick-borne encephalitis consist of?

What is tick-borne encephalitis

Tick-borne encephalitis is a viral natural focal infection that is transmitted after tick bites and primarily affects 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 tried for a long time to study the disease, but only in the first half of the 20th century (in 1935) were they 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 vectors, the reservoir in nature is the tick;
  • tick-borne encephalitis virus is tropic or, in other words, tends to nerve 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 is destroyed in 10 minutes, boiling kills the causative agent of tick-borne encephalitis in just two minutes;
  • He doesn't like chlorine solutions or Lysol.

How does tick-borne encephalitis become infected?

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

Absolutely every resident of an area where there are outbreaks of infection can become infected. These statistics are disappointing for humans.

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

Routes of transmission of tick-borne encephalitis: transmissible, during a bite by an infected tick, and nutritional - after eating contaminated foods.

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

The place of frequent localization of the pathogen in the insect body is the digestive system, reproductive system 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 its course, the disease is conventionally divided into several periods. The initial phase occurs 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 gradual long-term recovery;
  • 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 the development of infection. Dangerous - because due to the absence of obvious signs, time can be lost 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 lasts only a few days (no more than 7).

In approximately 15% of cases, after a short incubation period, prodromal phenomena are observed, but they are nonspecific, and it is difficult to suspect this particular disease.

The first signs of tick-borne encephalitis appear:

  • weakness and fatigue;
  • various types of sleep disorders;
  • a feeling of numbness in the skin of the face or torso may develop;
  • one of the common signs of tick-borne encephalitis is various variants of radicular pain, in other words, unrelated pain appears along the nerves extending from the spinal cord - in the arms, legs, shoulders and other parts;
  • Already at this stage of tick-borne encephalitis, mental disorders are possible, when absolutely healthy man starts to behave unusually.

Symptoms of tick-borne encephalitis

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

During an 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, heartbeat becomes rare, changes appear on the cardiogram indicating conduction disturbances;
  • during the height of tick-borne encephalitis, breathing quickens and shortness of breath appears at rest, sometimes doctors record signs of developing pneumonia;
  • the tongue is covered with a white coating, as if affected digestive system, bloating and constipation appear.

Forms of tick-borne encephalitis

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

Eat various shapes tick-borne encephalitis.

Diagnostics

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

What can you find in general analysis blood? The level of blood neutrophils increases and ESR (erythrocyte sedimentation rate) accelerates. You can already suspect brain damage. At the same time, there is a decrease in glucose in blood tests, and protein appears in the urine. But based on these tests alone, it is still difficult to draw a conclusion about the presence of any disease.

Other research methods help to finally determine the diagnosis.

  1. The virological method for detecting tick-borne encephalitis is the detection or isolation of the virus from the blood or cerebrospinal fluid during the first week of illness followed by infection of laboratory mice.
  2. More accurate and faster serological studies blood RSK, ELISA, RPGA, paired blood sera of a sick person are taken 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 a diagnosis can be assumed.

Consequences of tick-borne encephalitis

Recovery from tick-borne encephalitis can take several months.

The European form of the disease is an exception; recovery occurs quickly without minimal residual effects, but untimely 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, fulminant forms of tick-borne encephalitis have been encountered, 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 a relapsing course of the disease occurs.

Treatment

Tick-borne encephalitis is one of the most serious illnesses; its course is never 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, medications are mainly prescribed to maintain the body:

  • apply hormonal drugs or glucocorticosteroids as anti-shock treatment for tick-borne encephalitis and to combat respiratory failure;
  • to relieve seizures, magnesium preparations and sedatives are prescribed;
  • for detoxification, an 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. Timely administration of this medicine contributes to a mild course of the disease and rapid recovery.

Immunoglobulin is used according to the following scheme:

  • prescribe the drug from 3 to 12 ml during the first three days;
  • in case of severe 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 rises again, the medicine is re-prescribed in the same dose.

Disease prevention

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

  • in order to avoid becoming infected with tick-borne encephalitis, you need to reduce the likelihood of ticks being sucked on during walks in nature from April to June, that is, use repellents;
  • when working outdoors in hotspots of infection, it is recommended to wear closed clothing even in summer and cover exposed areas of the body as much as possible;
  • after returning from the forest, you must carefully examine the clothes and ask someone close to you to examine the body;
  • A non-specific measure to prevent tick-borne encephalitis on your own property is mowing tall grass in spring and summer and using chemicals to repel ticks.

What to do if a tick is found on your body after a walk? It is necessary to remove it as soon as possible, this will reduce the likelihood of the pathogen entering the human blood. It is recommended not to throw away the insect, but to take it to the laboratory and analyze it for tick-borne encephalitis. In a hospital or paid laboratory, the blood-sucking insect is examined for the presence of the causative agent of the disease. A method is used to infect laboratory animals with a virus isolated from a tick. Even a small fragment is enough to make a diagnosis. They also use more quick way insect research - PCR diagnostics. If the presence of a pathogen in a tick is established, the person is urgently referred for emergency disease prevention.

There are two main ways to protect a person from developing the disease: emergency and planned.

  1. Emergency prevention of tick-borne encephalitis is carried out after contact with a tick. It can be started even before an insect infestation has been established. Immunoglobulin is used in a standard dose - 3 ml for adults, and 1.5 ml intramuscularly for children. The drug is prescribed as a preventive treatment of encephalitis to everyone who has not been vaccinated against infection. 10 days after the first dose, the medicine is re-administered, but in a double dose.
  2. Planned specific prevention of tick-borne encephalitis is the use of a vaccine against the pathogen. It is used for everyone living in areas with high morbidity rates. Vaccination can be done according to epidemic indications a month before the spring season of tick awakening.

It is planned to vaccinate against tick-borne encephalitis not only residents of infected areas, but also visitors in case of a business trip to a zone that is dangerous in terms of morbidity.

Today there are two main types of vaccines: tissue inactivated and live, but attenuated. They are used twice with repeated revaccination. But none of the available drugs protects 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? More long years the causative agent of the disease will be classified as life-threatening person. There are all the prerequisites for this - a huge number of animal carriers in nature, their distribution over a large territory, 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.

Tick-borne encephalitis is a fairly common infection. Most often it has an acute course. Intoxication leads to damage to the nervous system, which can lead to paralysis.

It is a mistake to believe that, based on the name, tick-borne encephalitis can only affect a person after a tick bite. This is the prevailing version. However, the virus of this disease can also be located in the bodies of rodents and insectivores.

The most unpleasant thing is that domestic goats, cows or sheep can have the virus. They may have the virus, but may not have symptoms of the disease. That is, these pets can be simple carriers. Human infection can occur through raw milk.

Tick-borne encephalitis is a viral pathology characterized by a transmissible mechanism of infection (through insect bites), and is also accompanied by febrile symptoms and damage to the tissues of the central nervous system.

Encephalitis is a disease of the brain. The suffix -itis directly indicates that the disease is inflammatory in nature. Often, in general, the cause of encephalitis (inflammation of the brain) is quite difficult to establish.

However, in the case of a tick bite, the cause is obvious. All that remains is to make sure that there was a bite (here is a tick that was removed from the skin) and establish the symptoms.

If you receive the tick-borne encephalitis virus through contaminated milk of a pet, it will be more difficult to verify the cause.

The disease has a pronounced natural focality. Conditions for the existence of ticks are:

  • favorable climate,
  • necessary vegetation,
  • landscape.
Map taken from simptomer.ru

Also, tick-borne encephalitis is characterized by seasonality.

A sick person is not a source of infection for others.

According to ICD10, tick-borne encephalitis is classified as A84.

Tick-borne encephalitis is the causative agent

Tick-borne encephalitis viruses belong to the group of RNA-containing flaviviruses.

According to genotype, tick-borne encephalitis viruses are divided into five types:

  • Far Eastern,
  • Western,
  • Greco-Turkish,
  • East Siberian,
  • Ural-Siberian.

For reference. The most common type of virus is the Ural-Siberian genotype of the pathogen.

The virus is quickly destroyed by boiling (within two to three minutes), during pasteurization, and also when treated with disinfectant solutions.

When dried or frozen, viral particles are able to maintain their activity for a long time.

Attention. It should be noted that pathogens can persist for a long time in food products(especially in milk, butter, etc.).

Infection with tick-borne encephalitis

The carriers of tick-borne encephalitis are ixodid ticks. Infection occurs predominantly through transmission: through tick bites, as well as when scratching the bite site, improper removal of the tick, etc.

Considering that pathogens are resistant to the effects of hydrochloric acid, in isolated cases, nutritional (food) infection with tick-borne encephalitis may occur when consuming foods containing viruses.

It should be noted that not all tick bites are accompanied by the development of an infectious process. According to statistics, the development of the disease after tick bites is recorded in approximately two to four percent of cases.

For reference. Infection of the ticks themselves with the encephalitis virus is observed in the bites of animals in which the viremic phase of virus circulation is observed (the virus is in the blood).

In this regard, infection with viral particles is observed in approximately five percent of ticks. However, after a tick is infected with a virus, this type The virus circulates in his body for life and is subsequently transmitted to the next generation of ticks. It is due to this that ixodid ticks are able to act as a natural reservoir of pathogens of tick-borne encephalitis.

The incubation period of viruses in the human body averages from ten to fourteen days (sometimes from one to thirty days).

For reference. A person cannot act as a source of infection (the virus is not transmitted from person to person).

Risk factors for infection

Maximum tick activity occurs from mid-spring to late summer. In this regard, the maximum risk of infection is observed during these months.

For reference. Most often, tick-borne encephalitis affects people from twenty to sixty years of age. The level of natural susceptibility to the disease is high and does not differ by sex.

City residents, who often relax in nature, get sick more often than rural residents.

Encephalitis is a group of diseases that are characterized by inflammation of the brain. In the territory Russian Federation Tick-borne encephalitis is a widespread viral infectious disease transmitted by ticks. This viral infection affects brain cells, nerve endings and, in the absence of the necessary prevention or treatment, can be fatal. We 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 you think 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. It is transmitted by ixodid ticks, but a person can become infected from wild or domestic animals and birds, as well as after consuming raw cow (goat) milk.

The incubation period for viral encephalitis ranges from 10 to 30 days. The development of the disease begins immediately after the pathogen enters the blood. Moreover, only a small amount is sufficient, which is carried with saliva, even if the tick has attached itself to the skin for a short time.

The development of encephalitis is accompanied severe pain in the muscles, headache, increased body temperature up to 40 degrees Celsius, sleep disorders, nausea and vomiting. The mentioned symptoms can last 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 the following types:

  1. 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.
  2. Meningeal. A fairly common form, it manifests itself in the form of headaches and stiffness of the muscles in the back of the neck. The pathology is accompanied by Kernig's sign (the patient's leg, lying on his back, passively bends at an angle of 90° in the hip and knee joints (the first phase of the study), after which the examiner makes an attempt to straighten this leg in knee joint(second phase). If a patient has meningeal syndrome, it is impossible to straighten his leg at 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.
  3. 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, and muscle twitching.
  4. Poliomyelitis. The symptoms are clear from the name and are similar to clinical manifestations polio. The patient suffers from fever and the muscles of his neck and arms are paralyzed.
  5. Polyradiculoneuric. A very rare form of infection. Nerve nodes are affected, which manifests itself in numbness and tingling of the extremities.

To accurately diagnose the disease, it is necessary to take a blood test. The disease is identified by the presence of antibodies produced by the human immune system.

Treatment of tick-borne encephalitis

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

After suppression of the virus in recovery period the patient is administered neuroprotectors and prescribed a course of physical therapy and (or) massage. Upon completion of the course of therapy, it is possible residual effects caused by encephalitis - atrophy of the shoulder girdle, full-blown attacks of epilepsy with muscle twitching.

Preventive actions

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

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

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

  • 2 tablets 1 time per day throughout the spring-summer period, when there is a danger of tick bites and virus infection;
  • 2 tablets 3 times a day 2 days before visiting an area where ticks may live.

If the tick has already attached itself to the skin, it must be removed with tweezers or thread, and then take a course of iodantipyrine 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 completing the course, you should re-donate blood for analysis.