Disease tick-borne encephalitis symptoms. What are the symptoms of an encephalitis tick bite in humans?

Definition of illness. Causes of the disease

Tick-borne encephalitis- this is an acute and chronic natural focal infectious disease caused by the tick-borne encephalitis virus, which leads to an acute fever, damage to various parts of the nervous system in the form of flaccid paresis and paralysis. As a rule, it is transmissible, that is, it is transmitted by blood-sucking insects.

Etiology

The tick-borne encephalitis virus was first isolated in 1937 by L. Zilber.

Group - arboviruses

Family - Togaviruses

Genus - Flavivirus (group B)

The species is a tick-borne encephalitis virus, which is divided into six genotypes (the most significant are the Far Eastern, Ural-Siberian and Western).

Tick-borne encephalitis is an RNA virus that is localized in the nervous tissue. It has a spherical shape 40-50 nm in diameter. It contains a nucleocapsid surrounded by an outer lipoprotein membrane with glycoprotein spines embedded in it (capable of sticking together red blood cells).

It is well preserved at low temperatures, resistant to drying (at low temperatures), in milk (including in the refrigerator) it lasts up to two weeks, in butter and sour cream - up to two months, at room temperature it is inactivated for 10 days, at boiling perishes in two minutes, at a temperature of 60 ° C loses its properties after 20 minutes. Household disinfectants and ultraviolet light also lead to its rapid death. Antibiotics have no effect.

Epidemiology

Natural focal disease. The distribution area covers Siberia, the Far East, the Urals, the European part of Russia, as well as Europe.

The main reservoirs of infection are ticks Ixodes persulcatus (taiga ticks) and Ixodes ricinus (dog ticks), sometimes other representatives of ticks.

The secondary reservoir of the virus in nature is warm-blooded mammals (hares, squirrels, chipmunks, mice, foxes, wolves, goats and others) and birds (thrush, bullfinch, black grouse and others).

Female ticks are able to transmit the acquired pathogens of the virus to their offspring, which ensures a constant level of infectivity of these arthropods and the circulation of the pathogen.

One tick can contain up to 10 10 viral particles, and the ingestion of only 1: 1,000,000 shares in the human body may well lead to the development of the disease. The fatter the tick, the greater the concentration of the virus in it.

The main circulation of the virus: ticks - hosts (animals and birds) - ticks. When a person is infected, the cycle is interrupted, because after the virus enters the human body, it stops spreading (biological deadlock).

The disease is characterized by autumn-summer-spring seasonality in the middle lane, due to peaks in tick activity, depending on natural and climatic conditions. Sometimes there are cases of activation of ticks and diseases in winter during thaws.

Tick ​​habitats are deciduous and mixed deciduous-coniferous forests with a pronounced shrub and grass cover, as well as paths of animals that feed ticks.

Infection occurs when ticks attack people in the suburban area, fields, forests, summer cottages during rest, collecting forest gifts. Often, cases of infection are also recorded in the cities themselves: in park areas, lawns. Mechanical transfer of ticks on clothes, things, products and their creeping onto people who have never visited nature is possible.

Transmission mechanisms:

If you experience similar symptoms, consult your doctor. Do not self-medicate - it is dangerous for your health!

Symptoms of tick-borne encephalitis

The clinical picture of the disease may vary depending on the serotype of the virus: as a rule, the Far East and Siberian variants are more severe; the course of the disease in the European part of the Russian Federation and Europe is marked by a milder and more favorable course.

The incubation period is from 1 to 35 days (on average 2-3 weeks), there is no clear relationship between the severity of the disease and the incubation period.

Schematically, the course of the disease in the acute period can be divided into six stages:

• infection;
• incubation period;
• prodromal period (the appearance of precursors of the disease);
• feverish period;
• early convalescence (recovery);
• recovery period.

Most often, the disease occurs in a latent or mild form, manifested by a slight increase in body temperature, a mild headache without a clear localization, general malaise and sleep disturbances (up to 90% of all cases).

Sometimes, in cases of a more pronounced course, the disease begins with prodromal phenomena in the form of chilling, weakness, heaviness in the head, diffuse headaches of low intensity for 1-2 days. Then the disease manifests itself with a sharp increase in body temperature up to 38-39 ° C, a sharp chill, sweating, severe headaches of a bursting nature, often accompanied by nausea, vomiting and impaired coordination. The patient is inhibited, apathetic, sluggishly reacts to external stimuli. His face, neck and chest are hyperemic. Perhaps the appearance of pain in various parts of the body, muscles and joints, sometimes there are fascicular twitches. In the future, weakness, increased sweating, fluctuations (lability) of blood pressure, paresthesia (numbness) of certain parts of the body without impaired motor functions increase. Symptoms of damage to the meninges appear, such as stiff neck, symptoms of Kernig and Brudzinski.

With alimentary infection (through food), abdominal pain, diarrhea, the appearance of a dense white coating on the tongue, as well as a two-wave febrile reaction are possible:

• short first wave of fever within 2-3 days;
• the second rise in temperature after a week-long "break" (usually more severe and prolonged).

With a favorable course, these signs gradually regress, sometimes leaving behind residual (residual) phenomena of varying severity and duration.

In some cases, the symptomatology increases and manifests itself in the form of severe toxicosis, the appearance of focal symptoms, paresis, impaired consciousness, breathing and the activity of the cardiovascular system. The prognosis in such cases is serious.

In the chronic course of the disease a wide polymorphism of clinical manifestations is possible, but the following signs are more often observed:

The pathogenesis of tick-borne encephalitis

The entrance gate is the skin damaged by the tick, the mucous membranes of the intestines, stomach, rarely the conjunctiva of the eye (when the tick is smeared and the hands are not washed).

Viremia - the entry of the virus into the blood and its spread in the body - goes through two stages.

Hematogenously, the virus enters the brain, where it actively multiplies, along the way, moving more slowly along the lymphatic tract, sensitizes (increases sensitivity) segmental tissue areas - often more significant neurological changes are detected in these places.

After the multiplication phase in the nervous tissue, the virus enters the blood again and causes re-sensitization of already previously sensitized tissues. This leads to a specific allergic reaction, alteration (functional damage) of nerve cells and impaired microcirculation. In various parts of the nervous system, foci of micronecrosis are formed, supported by a generalized inflammatory process in the nervous tissue (with predominant involvement of the central parts), which determines the severity of the symptoms of the disease.

Due to the cytopathic action of the tick-borne encephalitis virus (degenerative change), there is a depression in the production and a decrease in the content of circulating T-lymphocytes, as well as a delayed reaction of the proliferation of B-lymphocytes (sometimes only by three months), i.e., an immunodeficiency state develops that supports the development of pathological changes in the brain brain. The developing immune response deactivates viral particles first in the intercellular space, then destroys infected cells when the complement system is attached.

In some cases, the virus triggers mechanisms to evade the immune response (features of individual strains of the virus, antigenic drift, individual characteristics of human immunological reactivity, etc.), which makes it possible for it to stay in the body for a long time and form chronic forms.

After an infection with recovery, a stable (possibly lifelong) immunity remains.

Classification and stages of development of tick-borne encephalitis

According to the clinical form:

1. Acute tick-borne encephalitis:
2. Inapparent (hidden) form - detection of specific markers of infection in the blood in the absence or minimal severity of clinical manifestations.
3. Feverish form - a sudden increase in body temperature up to 38-39С, nausea, sometimes vomiting, increased tone of the occipital muscles without changes in the composition of the cerebrospinal fluid (meningismus), general weakness, sweating lasting about a week. As a rule, it ends favorably, after which asthenovegetative syndrome is possible for an average duration.
4. Meningeal form (the most common manifest form) - the occurrence of all manifestations of the febrile form with the addition of pathological symptoms of irritation of the meninges, severe toxicosis. Sometimes, with the addition of transient scattered neurological symptoms, a change in tendon reflexes, anisoreflexia (dissimilarity of reflexes), facial asymmetry, and more occur. CSF changes are characterized by an increase in intracranial pressure up to 300 mm of water. Art., lymphocytic pleocytosis is detected up to 300-900 cells in 1 μl, the protein level rises to 0.6 g/l, the sugar content does not change. In general, the duration of the disease is about 20 days, it often proceeds favorably, residual effects are possible in the form of intracranial hypertension, headaches, low-grade fever up to 2-3 months.
5. Meningoencephalitic (focal and diffuse) form is a severe, life-threatening form of the disease. With diffuse lesions, toxic and cerebral symptoms, the development of seizures, impaired consciousness of varying severity, sometimes to coma, come to the fore. With a focal lesion against the background of cerebral and toxic symptoms, motor disorders develop - central paresis (usually completely reversible).
6. Polioencephalitic form - violations of swallowing, drinking, speech, various visual impairments, sometimes twitching of the tongue, when trying to drink water pours out through the nose, paresis of the soft palate is possible. Characteristic manifestations are respiratory disorders of the central type, vascular collapse and heart paralysis, which leads to death. With a favorable course, a long (sometimes more than a year) asthenic syndrome is characteristic.
7. The polioencephalomyelic form is an extremely severe course, characterized by damage to the cranial nerves, paralysis of the heart and breathing with a mortality rate of up to 30%. In other cases, there is a high probability of paralysis and the transition of the disease to a chronic form.
8. Poliomyelitis form - flaccid paralysis of the muscles of the neck, shoulder girdle and upper limbs, periodic disturbances in the sensitivity of these areas, atony. Very indicative of the so-called. drooping head syndrome, when the patient cannot keep his head upright. Sometimes breathing is affected due to damage to the diaphragm, which is quite dangerous. The course of this form is long, the restoration of the function of the affected departments does not always occur in full.
9. Two-wave course indicating the form of the second wave - the first wave of fever within a week with a complex of cerebral and intoxication disorders, then a period of imaginary well-being lasting 1-2 weeks, and the onset of the second wave of fever, accompanied by the development of meningeal and focal symptoms, usually without severe consequences.
10. Chronic tick-borne encephalitis:
11. Hyperkinetic form - Kozhevnikov's epilepsy, myoclonus epilepsy, hyperkinetic syndrome.
12. Amyotrophic form - poliomyelitis and encephalopoliomyelitis syndrome, as well as syndrome of disseminated encephalomyelitis and amyotrophic lateral sclerosis.
13. Rare syndromes.

In the course of the disease is:

• acute - 1-2 months;
• acute protracted (progredient) - up to 6 months;
• chronic - more than 6 months,

Chronic tick-borne encephalitis is caused by a long stay in the body of the tick-borne encephalitis virus. It usually develops in childhood and adolescence. There are four forms:

• initial - continuation of the acute process;
• early - during the first year;
• late - after a year from an acute form;
• spontaneous - without an acute period.

The severity of tick-borne encephalitis:

Complications of tick-borne encephalitis

Tick-borne encephalitis itself is a serious disease that sometimes leads to death of a person. However, against the background of its course, additional complications are possible, significantly aggravating the prognosis:

Diagnosis of tick-borne encephalitis

Laboratory diagnostics:

Differential diagnosis:

Treatment of tick-borne encephalitis

With the development of the disease, there is no specific highly effective etiotropic treatment.

In the acute period, strict bed rest, detoxification therapy, rational nutrition, the use of vitamins, means of improving cerebral circulation, and hormone therapy are indicated. If necessary, the patient can be transferred to the intensive care unit, prescribe the use of antispasmodic and relaxing drugs.

Sometimes in practice, immunotherapy agents, specific immunoglobulins, gamma globulins are used - their use to some extent can reduce the severity of the manifestations of tick-borne encephalitis and the severity of long-term consequences, but these drugs cannot radically affect the outcome of the disease.

In the chronic phase of the disease, it is possible to use vitamin and immunostimulating therapy, the use of antihypoxants and adaptagens.

For those who have been ill, regardless of the severity of the disease, dispensary observation is established for up to three years with periodic examination by a neurologist and examinations (according to indications).

Forecast. Prevention

With inapparent, mild forms of the disease, the prognosis is usually favorable. With the development of more serious forms of the disease, the formation of sufficiently long-term, sometimes life-long residual effects, accompanied by astheno-neurotic manifestations, headaches of varying intensity, and a decrease in mental and physical performance, is not excluded. In severe forms, the prognosis is unfavorable.

Vaccination is the most effective preventive measure to prevent the development of the disease. It is carried out using any registered tick-borne encephalitis vaccine. As a rule, it is performed first in the fall, then in the spring, then the next spring a year later, after which a subsequent revaccination is shown every three years (it is possible to determine the level of protective antibodies and correct the schedule). Such a scheme provides almost guaranteed protection against the development of the disease during infection. There are emergency vaccination schemes, but their effectiveness is lower than the main ones.

When an unvaccinated person is bitten by an infected tick, in Russia they resort to the introduction of immunoglobulin, but its effectiveness and safety are in doubt.

Measures of non-specific prevention are similar to the prevention of tick-borne borreliosis:

• when visiting the forest park zone, it is worth wearing protective tight clothing, as well as using repellents that repel ticks;
• periodically examine the skin and clothing (every two hours);
• carry out centralized treatment of forest and park lands with means of combating ticks.

If a stuck tick is found, you should immediately contact the trauma department to remove the tick and send it for examination. Also, in parallel, it is necessary to contact an infectious disease specialist for observation, examination and recommendations for preventive therapy.

Tick-borne encephalitis is a severe infectious disease that is transmitted to humans from encephalitis ticks. The virus sneaks into the brain and spinal cord of an adult or a child, causes severe intoxication and affects the central nervous system. Severe encephalitic forms without timely treatment can lead to paralysis, mental disorders and even death. How to recognize the symptoms of a dangerous pathology, what to do if a tick-borne infection is suspected, and what is the importance of vaccination in the prevention and treatment of a deadly disease?

General description of the disease

Tick-borne encephalitis is classified as a natural focal disease that occurs in certain areas. The carriers of the pathogen are wild animals, in this case the encephalitic tick. The main foci of tick-borne pathology are Siberia and the Far East, the Urals, the Kaliningrad region, Mongolia, China, some areas of the Scandinavian Peninsula and Eastern Europe. Every year about 5-6 thousand cases of encephalitic tick infection are registered in our country.

The severity of the course and the form depend on the immunity of the bitten person, the amount of the virus in the body, the number of bites, and also on the geographic location. Specialists divide the encephalitic tick virus into 3 subspecies: Far Eastern, Siberian and Western. The most severe forms of the disease - after the attack of ticks in the Far East, 20-40% of death. If an encephalitic tick attack occurred in the European part of Russia, the chances of avoiding complications are much higher - the mortality rate here is only 1-3%.

Forms of the disease

Symptoms after an encephalitic tick attack are very diverse, but in each patient the period of the disease traditionally proceeds with several pronounced signs. In accordance with this, 5 main forms of tick-borne encephalitis are distinguished.

1. Feverish, or erased (the most successful prognosis with treatment).
2. Meningeal (diagnosed most often).
3. Meningoencephalitic (occurs in 15% of the country as a whole, in the Far East 2 times more often).
4. Poliomyelitis (diagnosed in a third of those affected by encephalitis ticks).
5. Polyradiculoneuritis.

A special form of tick-borne infection - with a two-wave course. The first period of the disease is characterized by febrile symptoms and lasts 3-7 days. Then the virus penetrates the meninges, neurological signs appear. The second period lasts about two weeks and is much more severe than the febrile phase.

Causes and ways of transmission of the virus

The causative agent of lethal encephalitis is an arbovirus from the genus Flaviviruses. It is very small (2 times smaller than the influenza virus!), so it easily and rapidly passes through human immune defenses. Arbovirus is unstable to UV radiation, disinfection and heat: when boiled, it dies after a few minutes. But at low temperatures, it maintains vital activity for a very long time.

The virus usually lives in the body of ixodid encephalitis ticks and attacks not only humans, but also livestock: cows, goats, etc. Therefore, there are 2 main ways to get encephalitis: through an insect bite and alimentary (fecal-oral method). In this regard, we can name 4 main causes of encephalitic tick infection:

• Immediately after the bite of an infected insect;
• If tick feces get on the skin and penetrate into the blood through scratching;
• If, when trying to remove a stuck encephalitic tick, it bursts, and the virus gets inside;
• After drinking unpasteurized milk infected with an animal tick.

Symptoms

While the latent period of infection lasts, the virus multiplies at the site of the bite or in the walls of the intestine, then penetrates into the bloodstream and scatters throughout the body. Regardless of the form of the disease, the initial symptoms of tick-borne encephalitis in adults are the same:

• A rapid rise in temperature to 39-40º and chills;
• Head and lumbar pain;
• Muscle aches;
• Lethargy with lethargy;
• Cutting in the eyes and photophobia;
• Nausea, vomiting and convulsions (in isolated cases);
• Redness of the skin on the face and down to the collarbones;
• Rapid breathing and slow pulse;
• Plaque on the tongue.

If the virus has time to penetrate the meninges, there are some signs of damage to the nervous system: the skin becomes numb, muscles weaken, goosebumps run through the body, and sometimes convulsions.

Children experience similar symptoms after being attacked by a tick infected with encephalitis. The main difference is that the disease develops more rapidly and is more severe. Children especially often have convulsive seizures against the background of high temperature.

Feverish form

The febrile form of the infection develops if the virus circulates in the blood and does not penetrate the lining of the brain.

At first, the disease looks like a classic: fever begins (high temperature alternates with chills), constant weakness, the bitten person is tormented by pain in the head, nausea, and sometimes vomiting. Mild neurological symptoms may be observed: mild muscle pain, backache. Sometimes - goosebumps in separate attacks.

After recovery, within a month, individual signs may appear: weakness, poor appetite, sweating, heart palpitations.

meningeal form

This is the most common form of the disease after the bite of an encephalitic tick. Arbovirus in this form affects the membranes of the brain and spinal cord. The disease begins with classic signs: a high temperature, then an unbearable headache, which instantly increases with the slightest movement, dizziness, nausea and vomiting, pain in the eyes from bright light, lethargy, weakness and lethargy.

After infection with an encephalitic tick, rigidity occurs (the muscles of the neck are so tense that the head constantly tips back), tension in the muscles of the lower leg and the inability to straighten the leg at the knee, heightened skin sensitivity (even clothes bring pain).

This period lasts 7-14 days, after recovery, lethargy, photophobia, and depressive mood may persist for about 2 months.

Meningoencephalitic form

With this form of infection, the bites of encephalitis ticks and the penetration of the virus cause damage directly to the brain cells. The symptoms of pathology depend on which part of the brain is affected by the arbovirus and what is the size of this lesion.

If the meningoencephalitic form of encephalitis develops, neurological symptoms will come first: disturbances in movements and facial expressions, loss of orientation in time and space, clouding of consciousness, sleep problems, delirium and hallucinations, muscle twitching, shaking arms and legs, damage to the facial muscles (strabismus, double vision, problems with swallowing, slurred speech, etc.).

Specialists divide meningoencephalitis into 2 forms: diffuse and focal. Diffuse infection causes disorders of consciousness, epileptic seizures, breathing problems, central paresis of facial expressions and language, that is, a decrease in muscle strength. Focal tick-borne encephalitis is manifested by weakness in the muscles after convulsions, monoparesis, seizures.

Polio form

Poliomyelitis tick-borne encephalitis is a disease of cells exclusively in the spinal cord. In the prodromal period of such a pathology, for a couple of days, the patient feels weak, gets tired very quickly. Then difficulties with movement begin: first, the facial muscles suffer, then the arms and legs, after which certain areas of the skin begin to go numb and lose sensitivity.

A person infected with an encephalitic tick cannot hold his head in the usual position, make normal movements with his hands, suffer from severe pain in the back of the neck, shoulder girdle and arms. Muscles can significantly decrease in volume. All signs of other encephalitic forms may also appear.

Polyradiculoneuritic form

With this type of tick-borne infection, peripheral nerves and roots suffer. The main manifestations are pain throughout the body, tingling and crawling on the skin, Lasegue symptoms (pain along the sciatic nerve when raising a straight leg) and Wasserman (pain in the front of the thigh when raising the leg).

The danger of the polyradiculoneuritis form is the development of Landry's ascending paralysis. In this case, flaccid paralysis starts from the legs, rises up the torso, covers the arms, then the facial muscles, pharynx, tongue, and can lead to respiratory failure. Paralysis can also start from the muscles of the shoulder and move upward, involving the muscles of the neck.

Two-waveform

Some experts classify such tick-borne encephalitis as febrile, but most scientists distinguish it as a separate type.

After the bite and the incubation period, the temperature jumps sharply, the patient feels dizzy, nausea and vomiting begin, pain in the arms and legs, sleep and appetite disturbances. Then, for 3-7 days, a feverish period lasts, which is replaced by a calm for one to two weeks.

The second wave of encephalitis begins just as abruptly, to the listed symptoms are added signs of meningeal and focal meningoencephalitic forms. The prognosis for recovery with this type of encephalitis is favorable, as with a normal febrile infection.

Diagnostics

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 year, whether the vaccine was given, whether there was a tick bite) and laboratory tests (analysis of the tick itself - optionally, analysis of cerebrospinal fluid and etc.).

The first thing to do if a tick attacked is to examine the sore spot. The bite of an infected insect is just a red, inflamed wound, and the encephalitic tick itself looks like a normal one. Therefore, in any case, emergency prevention of tick-borne encephalitis is needed - to introduce immunoglobulin against the virus, and then do an analysis. The main diagnostic methods that must be done after a tick bite are:

• Analysis of patient complaints and medical history;
• General examination (analysis of all symptoms in order to identify typical manifestations of tick-borne encephalitis);
• Virological analysis of blood and cerebrospinal fluid;
• Analysis of arbovirus and determination of its particles in physiological fluids;
• Immunoenzymatic analysis (level of antibodies in the blood);
• General and biochemical blood tests to determine the severity and characteristics of the CNS lesion.

Treatment

Today, the treatment of tick-borne encephalitis is carried out exclusively in a hospital, the main medicine against the disease is immunoglobulin (a special solution from the serum or plasma of donor blood with antibodies to the virus). Immunoglobulin has practically no adverse reactions, but when used against tick-borne encephalitis, it can cause a serious allergy, therefore it is used strictly for its intended purpose and under the supervision of a doctor.

What to do if a person is attacked by a tick? The first step is to remove it and urgently go to the hospital.

Regardless of whether the attacked tick was encephalitis, the victim is given a specific immunoglobulin against tick infection for 3 days. Immunoglobulin is injected strictly intramuscularly: with a febrile form daily for 3-5 days, meningeal - every 10-12 hours for 5 days, the dose is 0.1 ml / kg. In more severe forms, for the treatment of tick-borne encephalitis, immunoglobulin against the disease is prescribed in increased doses.

The doctor prescribes further treatment for tick-borne encephalitis depending on the encephalitis form and the severity of symptoms:

• Detoxification and restorative therapy;
• Resuscitation measures (artificial ventilation of the lungs, oxygen mask, etc.);
• Decreased cerebral edema;
• symptomatic treatment.

In addition, after recovery, the patient remains under the supervision of a neurologist for up to 3 years.

Prevention

Prevention of tick-borne encephalitis is carried out in two directions: vaccination (specific prophylaxis against tick-borne encephalitis) and preventive measures (non-specific).

Emergency prophylaxis against the encephalitic tick virus is an immunoglobulin that is administered within 3 days after the bite. Immunoglobulin is also administered to unvaccinated individuals in dangerous (endemic) areas. The protective effect lasts about 4 weeks, if the danger persists, immunoglobulin can be re-administered.

If immunoglobulin is more often used for emergency vaccination, then a routine vaccination against an infection is a special vaccine of a killed virus. With the standard vaccination schedule, the first vaccination is carried out from November, the second should be done after 1–3 months, and the third after 9–12 months. In an emergency scheme, the second vaccination can be done after 14 days, the third - after 9-12 months.

What should be done to avoid an insect attack? Non-specific prevention includes the following measures:

• When hiking in the forests, wear thick clothing and use repellents;
• Upon returning, do a thorough examination of exposed areas of the body;
• Boil raw milk from domestic goats and cows;
• If you find a stuck tick, immediately remove it or go to the nearest hospital.

For complete protection against the encephalitis mite in dangerous areas, it is necessary to combine vaccination against a dangerous infection and usual preventive measures.

Differently - meningoencephalitis. Every year in Russia there are thousands of cases of tick-borne encephalitis. In more 20% cases this so-called. spring sickness develops in children. The disease is infectious viral in nature. The virus enters the body through the hematogenous route (through the blood) after a bite of an encephalitic tick (ixodid tick).

It affects the following body systems:

• central nervous system;
• peripheral nervous system;
• gray matter of the brain (polyencephalitis);
• white matter of the brain (leukoencephalitis);
• both substances at the same time (panencephalitis).

A person affected by encephalitis has a high risk of death, but even if a person still manages to survive, his existence turns into an everyday struggle. The patient loses most of his functions, falls into paralysis, becomes an invalid.

Signs of encephalitis in a person after a bite

Signs of a particular disease can only be detected by a specialist when performing laboratory and clinical studies. This is the main difference between signs and symptoms of the disease, which are easily recognized by the patient himself.

To draw up a picture of the disease of tick-borne encephalitis, doctors resort to the following diagnostic methods:

• puncture of cerebrospinal fluid;
• blood test;
• x-ray;
• biological study of the tick-carrier.

The presence of a neuroinfection that causes encephalitis is signaled to doctors by the following signs:

• ring-shaped changes in the MRI of the brain;
• violation of cerebral circulation;
• circulatory disorders in the neck, face, chest and mucous membranes of the mouth and nose;
• change in the composition of the liquor;

The disease is divided into two categories:

1. primary (independent);
2. secondary (develops against the background of other pathologies).

According to the course, the disease is classified into:

• spicy;
• subacute;
• chronic (disability).

Symptoms

Primary The symptoms of encephalitis are somewhat similar to those of a cold (flu-like). It manifests itself in an acute form.

Fever and intoxication begin, which are accompanied by classic symptoms of a cold:

Often, after a tick bite, a so-called. tick-borne erythema. The bite site actively turns red and increases in size, surrounded by an additional ring of a reddish hue. Such a symptom may signal other types of encephalitis (Lyme disease).

With the development of the disease, more severe symptoms are observed. Neurological changes appear:

• paralysis;
• loss of consciousness;
• coma;
• speech disorders;
• movement disorders;
• epileptic seizures.

A person infected with the encephalitis virus quickly gets tired and sleeps poorly, becomes sensitive to light. He may fall into a fever, which will be prolonged (up to 10 days). There are also cases of memory loss.

How is encephalitis diagnosed?

The tick-borne encephalitis virus destroys blood-brain barrier and thus enters the central nervous system through the blood, destroys neurons, causes vascular disorders, and affects the spinal cord sections. Often, due to the similarity of the manifestations of diseases, encephalitis is confused with a pre-stroke state.

Laboratory specialists can observe the following changes in the brain:

• tissue hyperemia;
• edema of the substance of the brain;
• infiltrates from brain cells;
• pinpoint hemorrhages (vascular damage);
• vasculitis (inflammation of blood vessels);
• the formation of necrotic foci;
• occurrence of fibrotic changes.

The manifestation of encephalitis is divided into several forms:

• feverish(the acute form lasts up to 5 days and manifests itself in the form of headache, lethargy, fever, nausea);
• meningeal(the most common form with symptoms of severe headaches, recurrent vomiting, photophobia, dizziness; a favorable course with recovery after 2-3 weeks);
• meningoencephalitic(a more severe form with pathological changes in the work of consciousness, delirium and hallucinations, convulsions are observed);
• polyencephalomyelitis(in the first days, general fatigue is noted, there is a violation of movement with muscle twitching, numbness of the limbs, control over the body is lost, pain in the muscles is felt, for 3 weeks the symptoms develop into muscle atrophy and loss of movement);
• polyradiculoneuritis(violation of sensitivity, pains are felt along the nerve pathways, tingling, paralysis of the lower sections, lumbar and shoulder girdle develops).

How long does it take for encephalitis to show up?

Ticks, whether female or male, regardless of the time they stay in the human body, infect with a virus immediately after the bite. The longer the pathogen is not removed, the higher the risk of getting more pathogen into the blood.

Does encephalitis show up quickly?

The disease has a certain incubation period (from 8 to 20 days). Its duration depends on the number of bites and the geographical area where the tick lives (the Far East and the Urals are the most dangerous regions).

There are cases when the virus manifested itself on the first day, and sometimes you had to wait a whole month. Already through 2 days after a bite, a virus is found in the brain tissue. After 4 days the concentration of pathogens in the gray matter becomes maximum.

What to do with a tick bite?

If, after a trip to the forest, you undressed naked, examined your body and found a tick stuck into the skin in some area, then a number of measures must be taken:

The most common areas of tick bites:

• armpits
• inner surface of the thighs;

Unfortunately, emergency therapy is effective only in 60% cases. Therefore, it is advisable not to allow a bite at all. To do this, each person must follow simple recommendations, especially if he often goes to nature and goes to the forest.

These measures include:

1. Putting on a special protective suit. Overalls fit snugly to the body and are fully tucked in. The fabric of such a suit is impregnated with a solution that repels insects. There is a protective hood and cuffs, as well as traps for ticks (special inserts that prevent ticks from moving along the body).
2. Take a shower. Ticks are susceptible to the smell of sweat. In order not to attract them to you, wash yourself before going out and use an antiperspirant.
3. The use of repellents (drugs against insects). Before going into the woods, treat your hazmat suit with an anti-tick spray. Do not apply the drug to the body. Make sure that the aerosol does not get on the mucous membrane of the mouth or nose.
4. Get vaccinated against tick-borne encephalitis. In many Siberian cities, school-age children are forcibly vaccinated against this virus. The vaccine is injected under the shoulder blade or in the shoulder. The procedure is recommended for children aged 4 years and older (imported vaccines are allowed from the age of twelve months). Revaccination is carried out every 3-5 years. Vaccination protects in 95% of cases.

Signs of the effects of an encephalitis tick bite

The disease leads to psychiatric and neurological consequences.

After a tick bite, the following diseases can develop:

1. Encephalomyelitis. Destruction of the myelin sheath. Accompanied by hemiparesis, ataxia, parkinsonism, oculomotor disorders, impaired consciousness.
2. Myelitis. Inflammation of the spinal cord. Manifested in the form of weakness, fever with chills, back pain, numbness of the limbs, loss of sensitivity.
3. Meningitis. Inflammation of the meninges of the brain. Symptoms - fever, severe prolonged headache, vomiting, lethargy.
4. Epilepsy. Convulsive attacks without loss of consciousness.

Encephalitis is accompanied by the following complications:

• memory loss;
• decrease in intelligence;
• disorder of motor functions;
• speech disorder;
• anorexia.

Conclusion

Tick-borne encephalitis is a viral disease that has no cure. The patient is prescribed supportive therapy aimed at combating recurring symptoms and ensuring his adaptation in society.

It is important to remember that:

• encephalitis virus is carried by ticks;
• the virus enters the blood immediately after the bite, and into the membranes of the brain - already on the second day;
• symptoms of the disease occur in the form of fever;
• destructive processes in the brain caused by the virus lead to loss of coordination of movement, paralysis, memory impairment, death;
• after a bite, it is necessary to remove the insect from the body and send it for laboratory analysis;
• to prevent infection, it is necessary to be vaccinated, wear protective suits, and use repellents that repel ticks.

Shoshina Vera Nikolaevna

Therapist, education: Northern Medical University. Work experience 10 years.

Articles written

Of particular concern is the focal form, which is the most unfavorable. The effects of a bite can be irreversible. Thus, death from tick-borne encephalitis is observed in 30 cases out of 100. Even if a person received timely and high-quality treatment, he may subsequently experience a convulsive syndrome, persistent paralysis of the muscles of the arms and legs, as well as a decrease in intellectual abilities.

Prevention measures for children and adults

As you know, any disease can be prevented and not treated later. This statement can be fully attributed to tick-borne encephalitis.

There are certain preventive measures, following which you can avoid an insect bite and infection into the body. Prevention of tick-borne encephalitis includes, first of all, organizational measures. The population living in regions that are unfavorable in terms of morbidity should be informed about the rules for visiting forest areas, parks and other places where ticks may live. During the period of insect activity, you need to visit such places in appropriate shoes and clothing, which should cover most of the body. Headgear (cap, panama, scarf) is required, under which hair is removed.

In case of a bite, you should immediately contact a medical facility so that a medical professional removes the insect. If it is not possible to go to the hospital, the tick is removed on its own, and then delivered to the laboratory for research.

A necessary preventive measure is vaccination, which can be general and emergency. The general is carried out according to the scheme: in autumn, in winter, then after 6-12 months, that is, three times. Emergency vaccination includes two, which are placed sequentially with an interval of 14 days. It is resorted to in cases where a person urgently needs to visit a dysfunctional region. It is valid for 1 season.

Specific prophylaxis involves the administration of immunoglobulin in case of a tick bite. This is necessary so that antibodies (immunoglobulins) to the tick-borne encephalitis virus can form in the blood. People who have been vaccinated have a significantly reduced risk of developing the disease.

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 ixodid 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), as well as its interaction with the circulatory system, are disturbed. 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 study 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, 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 EC;
• 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 donor 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 in others, persistent disorders of the nervous system are formed 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 remedy. 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 under a covered lid to infuse for 1 hour. 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 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 should be taken into account that the encephalitis vaccination does not prevent the disease, but only aims at its milder course, 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?

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