When infected with tick-borne encephalitis, the pathogen is localized in. How not to get tick-borne encephalitis

Tick-borne encephalitis - natural focal infection caused by viruses tick-borne encephalitis, transmitted transmissively (through insects) and alimentary (when eating the milk of sick animals), and clinically manifested by an infectious-toxic syndrome with a predominant lesion of the central and peripheral nervous system.

Tick-borne encephalitis is widespread with the presence of natural foci. There are the most endemic territories for tick-borne encephalitis (a high percentage of ticks infected with this virus). According to the results of 2012, these include the Kirov Region, Perm Territory, Nizhny Novgorod Region, Udmurtia, Bashkortostan, MariEl, Tatarstan, Samara Region, Sverdlovsk region, Tyumen region, Chelyabinsk region, Novgorod region, Pskov region, Leningrad region, almost the entire Siberian Federal District, the Far Eastern Federal District, part of the districts of the Yaroslavl, Tver regions. The disease is rare in the Central Federal District and does not occur at all in the Southern Federal District.

The symptoms of the disease are varied, which makes it difficult to recognize, but they are all associated with damage to the nervous system. Certain concerns are caused by the formation of chronic forms of the disease with the development of disability.

The causative agent of tick-borne encephalitis– An RNA-containing virus belonging to the Vlaviviridae family. There are 3 varieties of the virus: 1) Far East - the most virulent (can cause severe forms of the disease), 2) Siberian - less virulent, 3) Western - the causative agent of 2-wave encephalitis - causes mild forms of the disease.

Exciter features:
a) tropism (favorite defeat) to nervous tissue, the motor structures of the brain are mainly affected; b) the possibility of persistence (long-term presence) in the human body, which causes virus carrying (the virus is inside the cells and is not recognized by the immune system).

Properties of the virus: the ability to remain viable under low temperatures, however, high temperatures (for example, boiling for 2 minutes) are detrimental to it.

Causes of tick-borne encephalitis

The reservoir and carrier of the infection are ixodid ticks, which are distinguished by more than 15 species, however, two species are of epidemiological significance - Ixodes perculcatus (taiga) and Ixodes Ricinus (European). The ixodid tick senses a warm-blooded animal and a person at a distance of 5-6 meters. The tick sticks to the skin and injects the tick-borne encephalitis virus into the bloodstream. Why does a person not feel a bite? This is due to the presence of analgesic, vasodilating and hemolyzing substances in ticks. The result is pain relief, good blood filling of the bite site and a decrease in blood clotting. The tick “eats up” when it increases 120 times. In the foci of tick-borne encephalitis, after a tick bite, immunity can develop, there will be no disease - this is called pro-epidemic - that is, some local residents are already protected from this disease. There are two seasons of tick activity and the danger of human infection: spring (May-June) and late summer (August-September).

Ways of transmission of infection:

Transmissible (with a tick bite), and it must be remembered that the tick crawls over clothes in search of an open place, and over the body in search of a bite site, therefore, after visiting forest places, a bite can occur only after an hour;
- alimentary (the use of milk of sick animals - goats, cows, in the blood of which there is a virus);
- infection is possible when crushing ticks, which is categorically not recommended;
- transplacental (in case of a bite of a pregnant woman, transmission of the virus from mother to fetus).

The patient with tick-borne encephalitis is NOT contagious for others.
Susceptibility to infection is high, everyone is affected age groups However, men are more likely to get sick (up to 75%). Often there is a professional component of the disease, the risk groups for which are foresters, lumberjacks, geologists.

Symptoms of tick-borne encephalitis

The virus enters through human skin when bitten by a tick. Allocate: 1 phase- latent - the virus accumulates in the human body (there are no symptoms, this is an incubation period that lasts an average of 7-12 days, but can vary from 1 to 30 days); then comes 2 phase- the virus penetrates into the blood - viremia - and is introduced into the central nervous system (the patient has an infectious-toxic syndrome); 3 phase- neural (the patient has all the symptoms of damage to the nervous system); 4 phase- the formation of immunity (the patient recovers). Sometimes the virus does not leave the human body, but is integrated into the genome of brain cells and a progradient course is formed (recovery does not occur, the disease either subsides, then reactivates).

Allocate acute and chronic form of tick-borne encephalitis. acute form The disease is characterized by 2 syndromes:

1. Infectious-toxic syndrome (ITS)- Patients complain of high temperature up to 38-40°C for 4-6 days, severe headache that increases as the temperature rises, dizziness, vomiting for 1-2 days, sleep disturbance in the form of insomnia, muscle pain in the neck , shoulder girdle, upper limbs, less often in the lumbar region, lower extremities, weakness and fatigue, numbness in the upper extremities, muscle twitching, hypersensitivity skin(hyperesthesia).
Features in children: there may be loss of consciousness, the appearance of delirium, agitation, convulsive syndrome.
This syndrome occurs in all forms of tick-borne encephalitis.

2. Cranio-cervical syndrome- in most patients, redness of the face, neck, upper limbs and conjunctivitis.
Further symptoms depend on the form of the disease.

Febrile form of tick-borne encephalitis(predominant, recorded in 50-60% of patients). Only ITS and unsharply pronounced reddening of the skin. The current is favorable.

meningeal form. Occurs in a third of patients. Two syndromes on the 3rd-4th day of the illness are joined by: meningeal syndrome (severe persistent persistent headache, vomiting) and meningeal signs (symptom of Kernig, Brudzinsky, rigidity neck muscles) - only a doctor checks. Meningeal signs persist throughout the febrile period, then they can persist against the background of normal temperature for another 6-8 weeks. At spinal tap: an increase in the number of cells to several hundred in 1 μl, lymphocytes predominate, the liquid is transparent and flows out under pressure.

Meningoencephalitic form of tick-borne encephalitis. It is diagnosed in 10-20% of patients. It proceeds severely, as a focal or diffuse lesion of the brain is formed. Patients, in addition to the 2 syndromes described above, describe complaints characteristic of the cerebral syndrome: impaired consciousness from states of stupor to stupor (prolonged sleep), coma of varying degrees may develop, convulsive syndrome, there may be spastic hemiparesis (sharp and pronounced weakness in the upper and lower extremities on one side or the other). Fatal outcome may occur on the 2-4th day of illness in 20-30% of patients. In 20% of patients, a progradient course is formed with epileptic seizures and memory loss.

Poliomyelitis-like form. It is characterized by the appearance of flaccid paresis and paralysis, mainly of the upper limbs, neck and shoulder muscles. On the 1-4th day from the onset of temperature, a symptom of a “hanging head” appears, a symptom of a “falling hand”, tendon reflexes from the hands are not caused. Muscle atrophy is formed (at the 2-3rd week of the disease). There may be muscle twitches, a feeling of numbness in the limbs. In 50% of patients there is an improvement in the condition and recovery, and in 50% there is a progradient course and disability.

Polyradiculoneuritic form. Peripheral nerves are affected: patients complain of pain along the nerve trunks, paresthesia (a feeling of goosebumps in the limbs), symptoms of nerve tension - Lassegue, Wassermann, Landry's descending paralysis (determined by the doctor). Saved in 70% of cases residual effects, paresis, paralysis.

Two-wave form of the disease. Patients have a first wave of fever for a week without brain damage, then a period of normal temperature for 7-14 days, and then a second wave and a detailed picture of brain damage.

Chronic form of tick-borne encephalitis may be: primary progradient (symptoms of the disease intensify and do not go away already in acute period disease, despite ongoing treatment) or secondary progradient (symptoms of the disease resume again after a period of complete or partial recovery impaired functions).
Immunity after an infection is developed type-specific, long-term: antibodies to the virus persist throughout life. Relapses are almost non-existent.

Complications of tick-borne encephalitis

A complication may be the development of epilepsy after the meningeal form, cerebral edema with a fatal outcome after the meningoencephalitic form, damage to the cranial nerves with the development of strabismus, nasal voice, difficulty swallowing, speech, paralysis of the muscles of the neck, trunk and extremities after the poliomyelitis-like form, immobility and atrophy muscles after a polyradiculoneuritic form of encephalitis and other serious consequences.

Diagnosis of tick-borne encephalitis

A doctor can suggest tick-borne encephalitis after analyzing complaints, a thorough examination and collecting an epidemiological history (visiting a forest, field area, especially during the period of tick activity, a tick bite).

What to do with a tick bite? In no case do not comb the bite site and do not crush the tick itself, do not try to immediately pull it out with tweezers or something else. It is advisable to contact a surgeon for removal, but if this is not possible, then tie the thread into a knot as close as possible to the proboscis of the tick, then gently swing it and lift it slightly until it is removed. Remove carefully, as a head may remain inside, which is then very difficult to remove.

Treat the bite site with iodine. Do not throw away the tick itself, place it in glass container with a damp cotton wool, place in the refrigerator. As soon as possible, take the tick to a laboratory test in a virological laboratory. It is desirable to deliver the tick for research alive. The result of the analysis is extremely important for you, because on its basis follow-up measures will be taken in relation to you as a bitten person.
Laboratories can be at infectious diseases hospitals, treatment and diagnostic centers, hygiene centers, emergency rooms.

The final diagnosis is made after laboratory tests:
1) Detection of the E antiene of the tick-borne encephalitis virus using the ELISA reaction in ticks (the result is usually ready within a day), the cerebrospinal fluid of the patient, when examining the milk of a sick animal; or PCR diagnostics tick.
2) PCR diagnostics of the RNA virus of tick-borne encephalitis in the patient's blood - carried out no earlier than 10 days after the tick bite;
3) ELISA diagnostics for the detection of IgM antibodies in the blood no earlier than 2 weeks after the bite;
4) ELISA diagnostics of detection in blood IgG antibodies not earlier than 3 weeks after the bite.

Treatment of patients with tick-borne encephalitis

1) Organizational and regime measures: hospitalization in the infectious diseases hospital of all patients, bed rest for the entire period of fever and 7 days of normal temperature.
2) Etiotropic treatment (aimed at the virus) includes the introduction of a specific anti-tick immunoglobulin. Immunoglobulin is administered during the febrile period, when a second wave occurs, it is administered again at the same dose. You can prescribe iodantipyrin, interferon preparations (roferon, intron A, reaferon and others), interferon inducers (cycloferon, amixin, neovir).
3) Pathogenetic treatment includes detoxification therapy, dehydration, post-syndromic therapy (antipyretic, anti-inflammatory, drugs that improve microcirculation, cerebral circulation, and others).

At home, you can not try to treat tick-borne encephalitis. You can wait for complications, turn the disease into a chronic form, get disabled.

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

Prevention of tick-borne encephalitis

1) Specific prophylaxis includes vaccination against tick-borne encephalitis. There are several vaccines: cultural inactivated (Russia), Encevir (Russia), Encepur adult and children (Germany), FSME-immun-inject (Austria). This is a planned prevention, you need to be vaccinated in the fall (September-October). The course consists of 3 doses, the first two with an interval of 1 month, the third - a year after the second. Immunity lasts 3 years, then you need to do 1 revaccination for the next 3 years.

2) Passive prophylaxis - the introduction of a specific anti-tick immunoglobulin to persons who have been attacked by ticks. It is carried out and effective in the first 3 days after the bite.

3) Prevention with iodantipyrin. Several schemes are known - after a bite for 9 days (treatment course); - before visiting places with a possible tick attack.

4) Non-specific prevention - the use of repellents, acaricides, wearing a special protective clothing(or at least fill the pants in socks plus a long sleeve with a tight elastic at the end), self-examination during and after visiting the forests, eating boiled milk.

Infectious disease specialist Bykova N.I.

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 dangerous pathology what to do if you suspect a tick-borne infection 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 - Tick-borne Encephalitis. 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 of 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

The symptoms after the attack of the encephalitic tick are very diverse, but in each patient the period of the disease traditionally proceeds with several bright 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. The virus then enters 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

As long as it lasts latency period infection, the virus multiplies at the site of the bite or in the walls of the intestine, then enters the bloodstream and scatters throughout the body. Regardless of the form of the disease initial symptoms tick-borne encephalitis in adults manifests itself in the same way:

• 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 seizures against the backdrop of high temperatures.

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. There may be mild neurological symptoms: slight pain in the muscles, ache in the lower back. Sometimes - goosebumps in separate attacks.

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

tick infested encephalitic person unable to hold head in normal position normal movements hands, suffering from severe pain in the back of the neck, shoulders 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 way sciatic nerve when lifting a straight leg) and Wasserman (pain in the front of the thigh when lifting a leg).

The danger of the polyradiculoneuritis form is the development of Landry's ascending paralysis. In this case, flaccid paralysis starts from the legs, goes up the torso, covers the arms, then 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 analysis blood to determine the severity and features of CNS damage.

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 almost 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 routine vaccination against infection is a special vaccine of a killed virus. At standard scheme vaccination, the first vaccination is carried out from November, the second should be done after 1-3 months, 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.

The content of the article

Historical data of tick-borne encephalitis

Etiology of tick-borne encephalitis

Epidemiology of tick-borne encephalitis

Pathogenesis and pathomerphology of tick-borne encephalitis

Clinic of tick-borne encephalitis

Meningoencephalitic form

Poliomyelitis-like form

Polyradiculoneuritic form

Complications of tick-borne encephalitis

Prognosis of tick-borne encephalitis

Diagnosis of tick-borne encephalitis

Differential diagnosis of tick-borne encephalitis

Treatment of tick-borne encephalitis

Prevention of tick-borne encephalitis

Tick-borne encephalitis is an acute viral disease, which affects mainly nerve cells in the human body. These can be brain structures, peripheral innervation, or radicular nerve endings in the spinal cord. The main source of infection is the ixodid taiga tick. For reproduction of these insects blood of an animal or the person is necessary. At the same time, the rate of saturation in females and males of the taiga tick differs. The male is saturated within a few minutes, after which it falls off the skin of a person or animal. This often makes it difficult to diagnose the disease. The injured person cannot clearly say that he was bitten by a tick a few days ago. Usually, a tick bite for a person is painless. This is due to the ability of the tick to release an anesthetic before the bite. The female taiga tick is saturated for several days. In this case, there is a significant increase in the size of her abdomen. This does not go unnoticed. Removed if a tick is found, it should be given to special laboratory. There, specialists can determine the presence or absence of the encephalitis virus. Depending on the result of the analysis, preventive treatment, which is designed in case of infection to prevent the negative course of the disease and the onset of disability. The transmission of a virus through the bite of a tick is called parenteral route infections. The virus enters directly into the human blood

The second route of transmission of the virus is through digestive tract. In this case, infection occurs when drinking unboiled milk, which is obtained from a cow or goat infected with this virus. It is worth considering that animals do not suffer from such carriage. They may not have any symptoms. Therefore, in the period from May to August, it is necessary to pre-boil the milk for 5 minutes. This time is sufficient to completely inactivate the encephalitis virus. In this case, tick-borne encephalitis from infection through milk will not be terrible for you.

The first signs of tick-borne encephalitis

the first signs of tick-borne encephalitis may appear after 1 to 14 days from the moment of infection. Depending on the type of virus, the state of the human immune system, the incubation period is very variable. In recent years, there has been a lightning-fast course of the disease, in which, in the absence of adequate treatment, a sick person quickly falls into a coma and dies from paralysis of the central nervous system.

Among the first signs of tick-borne encephalitis include:

• sudden increase in body temperature up to 39-40 degrees Celsius;
• severe chills and weakness;
• thirst and increased sweating;
• feeling of numbness and slight tingling different areas skin;
• headaches and muscle pain;
• feeling of numbness in the lower and upper limbs;
• vomiting and lack of appetite.

AT further symptoms tick-borne encephalitis is growing rapidly. There is confusion, paresis of the muscles of the lower and upper extremities, stiff neck, spasms in the abdominal cavity.

Symptoms in various forms of the disease

There are several forms of tick-borne encephalitis. Depending on the form of the course of the disease, the symptoms of tick-borne encephalitis in humans differ. The most common are:

1. a form of tick-borne encephalitis in the form of a feverish condition;
2. form in the form of meningitis;
3. encephalitic form;
4. a form of tick-borne encephalitis with a polio course;
5. polyneuritic radiculitis form.

Most easy current seen in febrile form. In this case, the symptoms of tick-borne encephalitis occur in the form of fever, headache, loss of appetite, weakness and a feeling of weakness. Elevated temperature body lasts no more than 5 days. Studies of the cerebrospinal fluid show no abnormalities. No effects are observed.

In the meningeal form of tick-borne encephalitis, the symptoms of fever and intoxication are quickly supplemented by the meningeal complex. There is confusion, a decrease in reflex activity, vomiting with a fountain, coma. In the cerebrospinal fluid, leukocytosis is determined with a predominant content of pleocytes. Complications can manifest as recurrent headaches.

The most severe is the encephalitic form of tick-borne encephalitis. In this case, the arachnoid and subarachnoid membranes of the brain are affected. Symptoms of tick-borne encephalitis are growing rapidly. They include:

• hallucinations;
• coma;
• paralysis of the limbs;
• motor disinhibition;
• complete lack of orientation in space and time;
• high body temperature;
• repeated vomiting fountain.

Most common complication- epilepsy and paralysis of the limbs. When examining the cerebrospinal fluid, the in large numbers protein, leukocytes and fresh erythrocytes.

Poliomyelitis and radiculitis forms of tick-borne encephalitis have similar symptoms. These are pains in large joints, small paresthesias and paralysis small groups muscles. The muscles of the neck and chest are most commonly affected. Complication - muscle atrophy and complete immobility in the affected areas.

Treatment

Treatment of tick-borne encephalitis is possible only in the conditions of an infectious diseases hospital. It may be necessary to connect the patient to the devices artificial respiration and stimulation of the cardiovascular system. In severe cases, patients are placed in intensive care units.

The basis of the treatment of tick-borne encephalitis is based on specific virusotropic therapy. For this, gamma globulins and interferons are used. These substances are detrimental to the tick-borne encephalitis virus.

The second direction in the treatment of tick-borne encephalitis is the relief of symptoms. Abundant intravenous fluid infusions, the use of cardiac glycosides, and detoxification measures are shown. To stimulate the processes of regeneration of affected tissues, complex vitamin therapy and anabolic substances are used. Treatment of tick-borne encephalitis, depending on the form of the disease, can last from 5 days to several years.

Possible consequences

Various consequences of tick-borne encephalitis can manifest themselves throughout the life of the patient. In most cases, complications are formed already in the process of treating the underlying disease. A person gets persistent paralysis or muscle atrophy. This makes it impossible for independent movement or self-service. In some cases, the effects of tick-borne encephalitis appear several months later in the form of recurrent and progressive epileptic seizures.

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

Tick-borne encephalitis is sometimes called differently - spring-summer, taiga, Siberian, Russian. Synonyms arose due to the characteristics of the disease. Spring and summer, because the peak incidence occurs in the warm season, when ticks are most active. The first peak of the disease is recorded in May-June, the second - at the end of summer.

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

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

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

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

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

Features of the tick-borne encephalitis virus is a weak resistance to the action high temperatures, disinfectants and ultraviolet radiation. So, when boiled, it dies after 2 minutes and cannot be stored in environment in hot sunny weather. However, at low temperatures, it is able to maintain viability for a long time.

Incubation period

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

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

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

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

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

Symptoms of tick-borne encephalitis

Tick-borne encephalitis is viral infection, flowing at first under the mask of the usual colds. It can go unnoticed by the patient, and can cause severe damage to the nervous system.

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

Often the disease begins with the following symptoms:

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

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

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

Later violations may occur:

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

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

The most common and noticeable signs of an encephalitis tick:

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

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

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

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

Forms of tick-borne encephalitis

Currently, the following forms of the disease are distinguished:

Febrile form of tick-borne encephalitis

Tick-borne encephalitis in this form proceeds with a predominance of a feverish state, which can last from 2 to 10 days. as the most characteristic manifestations noted headache, weakness and nausea. At the same time, neurological symptoms are mild.

Meningeal

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

• weakness,
• increase in body temperature,
• sweating.

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

Meningoencephalitic

Meningoencephalitis is characterized by a two-wave temperature reaction. Each wave lasts from 2 to 7 days. At intervals of 1-2 weeks. The first wave passes with common toxic symptoms, and the second with meningeal and cerebral signs. The course of this form is favorable, there is a rapid recovery and no complications.

Polio form

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

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

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

Polyradiculoneuritic form

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

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

Signs of tick-borne encephalitis in children

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

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

The best measure to prevent tick-borne encephalitis in children and adults has been, and remains, vaccination. Vaccination against tick-borne encephalitis is shown to everyone who lives in epidemic foci or dwell in them.

Complications and possible consequences

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

Complications:

• Memory deterioration.
• Headaches.
• Complete or partial disturbances of movements and / or sensitivity in the limbs, mimic area.
• Reducing the strength and volume of muscles (often the upper shoulder girdle).

Diagnostics

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

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

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

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

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

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

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

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

Treatment

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

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

• antipyretic,
• detox drugs,
• vitamins,
• medications that normalize water balance organism.

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

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

Forecast

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

The consequence of tick-borne encephalitis may be memory loss, headaches, paralysis.

Prevention of tick-borne encephalitis

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

• vaccination - the most reliable protection against tick-borne encephalitis is own antibodies that are produced in response to vaccination. Traditionally, they are held in advance in the autumn-winter period.
• preventive measures (non-specific prophylaxis).

To preventive measures also include:

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

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