Viral encephalitis of the brain: symptoms, how it is transmitted, causes, treatment, consequences and prognosis

Encephalitis is an acute inflammation of the brain, most often caused by infection (viruses, bacteria, protozoa, fungi). In some cases, it may occur as a consequence of a severe allergic reaction or poisoning. Very rarely, encephalitis may have causes related to a violation of one’s own immunity, which attacks the brain substance (for example, demyelinating encephalitis in children).

Viral encephalitis can be caused by numerous viruses:

herpes simplex types 1 and 2;
Epstein-Bar;
flu;
varicella-zoster;
coxsackie group B;
measles;
rubella;
mumps (mumps);
tick-borne encephalitis;
rabies;
HIV;
cytomegalovirus;
arboviruses.

A distinction is made between a primary disease, when the brain is affected directly by the pathogen, and a secondary disease, which develops as an immunological response in response to an infection.

The disease, depending on the pathogen, is transmitted to humans from humans (in most cases), from arthropods (tick-borne encephalitis virus) and animal to humans (rabies). Humans, mammals, and birds can also be sources of arboviruses, but direct infection occurs due to the bite of mosquitoes or ticks. Thus, the disease is transmitted through transmission. Other methods of transmission of viral encephalitis pathogens are airborne, contact, fecal-oral, and sexual. In newborns, encephalitis can develop as a result of infection with herpes during the passage of the birth canal. In addition, intrauterine infection with enteroviruses is possible.

There are risk factors for the disease:

age (encephalitis is most often diagnosed in children and the elderly);
seasonality for some species (spring and summer);
suppressed immune system (due to pregnancy, taking medications against autoimmune diseases, HIV carriage, alcoholism);
certain geographical regions (some countries in Asia, Africa, Oceania, South America, areas of Siberia, the Far East, etc.).

In 1932, a severe epidemic of encephalitis occurred in the state of Missouri in the United States, which was caused by one of the arboviruses, the group B flavivirus, carried by Culex mosquitoes and the reservoir by birds. The infection quickly affected the nervous system, leading to intoxication and, in 30% of cases, death. The disease was named “St. Louis Encephalitis” after the city where the epidemic developed. Currently registered in North and South America.

During the development of viral encephalitis, depending on the pathogen, the following may occur in the brain:

hyperemia;
vasculitis (inflammation of the walls of blood vessels);
hemorrhages (point, sometimes extensive);
focal necrosis;
fibrous changes in the membranes;
formation of adhesions, glial nodes, cysts;
edema;
softening;
infiltrates;
neuronal dystrophy, neuronophagia;
widespread (diffuse) damage;
demyelination of nerve fibers;
destructive changes in glial cells.

Mechanism of infection

Foci of infection in nature are carried by rodents and other animals. For them, encephalitis is absolutely safe, unlike in humans. As for the ticks themselves, the dangerous virus exists in their bodies constantly. Encephalitis, transmitted from adults to larvae, never ceases to exist. Infection is increasing in numbers because the tick population in areas close to cities and residential buildings increases tenfold every year.

The greatest risk of infection with the encephalitis virus exists during periods of tick activity, in spring and summer. In autumn, cases of infection are recorded in minimal quantities. People who frequently visit forest areas are at risk.

Encephalitis is transmitted through the circulation of the virus between different animal species. Scientists have identified two mechanisms of infection:

The first mechanism of infection is characterized by entry of the virus through the skin. When a tick bites, pathological microorganisms enter the bloodstream. As a result of research, it was revealed that the longer the tick is on the skin, the more virus it will release. Accordingly, the more dangerous it is for humans. In this way, a large amount of the virus can be transmitted through the blood from an infected tick, in doses fatal to humans. Encephalitis will also be difficult to treat.

In a situation where, when removing an insect, it is accidentally crushed or not completely removed, then infection is also possible. Therefore, it is not recommended to try to do this on your own, but rather trust a doctor. It is important to know that the tick does not bite immediately. It moves on clothes, hair, branches, flowers and other things. Only after a period of time does it reach the skin.

Encephalitis causes damage to brain tissue. The inflammatory process can affect any part of the brain and even the spinal cord. Encephalitis may be purulent or non-purulent. The acute period of infection appears on days 6-10. There are cases when the disease became chronic. Then it becomes deadly.

Nutritional mode of transmission

It is important to know! Encephalitis cannot be transmitted from person to person. There are two specifically studied methods of infection: through the skin, through a bite, and through the mucous membranes of the gastrointestinal tract.

Infection with the virus through the alimentary method occurs as a result of consuming milk from a sick animal. Encephalitis in animals is completely asymptomatic. The infection enters milk through the blood, which in turn is a dangerous source.

Unprocessed milk that has not been boiled is dangerous. Scientists have found that the encephalitis virus lives in milk for about 2 months. Even derivative products such as cheese and cottage cheese are very dangerous to eat from an infected animal. The particular risk of this mode of transmission is that a large number of people can become ill.

Encephalitis can be determined by external signs:

the face and neck acquire a reddish tint;
the conjunctiva of the eyes becomes cloudy and red;
The upper part of the chest is also distinguished by redness.

The deterioration in health occurs suddenly. The pathology is often confused with other diseases, because the symptoms are common:

a sharp rise in temperature;
severe headaches;
nausea and vomiting;
sleep disorders;
sometimes loss of consciousness.

Infection occurs through a direct tick bite and through consumption of encephalitic milk. As a result of complications, paralysis develops. The formation of adhesions and cysts in the brain tissue is observed. The patient remains disabled. A fatal outcome is also possible when treatment does not bring results or the virus has spread to all important organs and systems.

Consequences

All infectious diseases of the brain carry the threat of intellectual and physical impairment. However, the consequences of encephalitis, which occurs in a mild form, are completely reversible - the person recovers completely and can return to professional duties almost immediately after recovery.

Whereas with moderate severity, the pathology leads to decreased hearing and vision, strangulation of speech and motor activity. The rehabilitation period can last up to six months and it is not always possible to fully restore health - the person remains with memory defects and decreased intelligence.

Severe encephalitis has a particularly severe effect - with the development of cardiac or respiratory failure, as well as coma. Death occurs in 2/3 of cases. Otherwise, when a person returns to consciousness, he remains deeply disabled and requires constant outside care. He shows a significant personality change.

Less commonly, the transition from an acute form of viral brain damage to a chronic type of disease occurs - exacerbation occurs with a decrease in immunity, overwork, or due to a person’s alcoholism. Symptoms will be less pronounced, however, complications occur more often. Timely seeking medical help and following all doctor’s prescriptions helps to exclude such an outcome. Encephalitis can be defeated and prevented if every effort is made.

Japanese encephalitis - how not to get infected

This type of encephalitis is also called mosquito encephalitis. The virus is transmitted by mosquitoes, which spread the infection in hot weather. The risk group includes people who are constantly outdoors in the evenings, when there are especially many mosquitoes. This type of virus is classified as naturally occurring. Distributed in almost all countries of the world.

Infected mosquitoes spread the infection through their bites. Children under 10 years of age are most often affected. However, mosquitoes infect various animals and rodents. In turn, animals can become carriers of the virus to people.

Encephalitis transmitted through milk from a sick goat or cow affects the human body, provoking pathological processes, primarily on the mucous membranes of the stomach. The virus develops not only in the intestinal tract and subcutaneous tissue. Sometimes during examination it is found in the lymph nodes or spleen. Treatment of this type of infection is long-term and complicated by disruption of the digestive system. This significantly impairs the use of medications.

Development of the virus in the body

It is known that the incubation period of encephalitis lasts on average from 7 to 10 days. It can last 30 days. Developments in modern medicine make it possible to use very effective treatments for encephalitis. More often, the prognosis depends on when the person sought help.

It is customary to determine the form of encephalitis based on what signs of the disease appear:

febrile;
meningeal;
meningoencephalitic;
polio;
polyradiculoneuritic.

According to statistics, about 70% of ticks living in mid-latitudes are infected with a dangerous virus. In places where there is an increased risk of spreading tick-borne encephalitis, vaccination is carried out. This measure is an excellent preventative method.

The clinical symptoms of encephalitis infection are very complex. It all starts with a mild fever and an increase in temperature to 40.5 degrees. Then vomiting, convulsions, joint pain, numbness of part of the face or torso are observed. Often the patient loses consciousness. Already in the first hours after a tick bite, the administration of immunoglobulin is indicated. This drug begins to fight the encephalitis virus during the incubation period. To make a diagnosis, blood and cerebrospinal fluid must be analyzed. Antibody tests are carried out in a hospital setting. A number of specialists are involved in the treatment of infection, performing strict monitoring of the patient’s condition.

Intramuscular injections of immunoglobulin are indicated for 5-7 days. Complex treatment necessarily includes the use of devices such as Prednisolone, Dextran, Procaine, Ibuprofen and others. Bed rest is mandatory. It is recommended to supplement the diet with vitamins and nutrients.

Tick-borne encephalitis: risk groups, treatment, complications, prevention

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Tick-borne encephalitis: risk groups, treatment, complications, prevention

People whose activities involve staying in the forest are at greatest risk of contracting tick-borne encephalitis: workers of timber industry enterprises, geological exploration parties, builders of roads and railways, oil and gas pipelines, power lines, topographers, hunters, tourists. In recent years, city dwellers have predominated among the sick, mostly (up to 75%) infected in suburban forests, gardens and vegetable plots.

Far Eastern tick-borne viral encephalitis, tick-borne encephalitis, Central European tick-borne encephalitis, viral diseases, fever

Hospitalization of patients with tick-borne encephalitis

Treatment of patients is carried out in the departments of infectious diseases hospitals. Hospitalization is mandatory, regardless of the severity of the disease at the time of the initial visit to the doctor at the first suspicion of tick-borne encephalitis. Patients should be hospitalized and treatment should be started as early as possible, otherwise the consequences of the disease may be unfavorable. In some cases, emergency care is required, without which the patient may die. It is necessary to ensure strict bed rest with the maximum exclusion of all stimuli (sound, visual, motor), which, due to the frequent presence of meningitis in patients, worsen the general condition and intensify meningeal manifestations.

Specific treatment of patients with tick-borne encephalitis

Specific treatment consists primarily of the administration of human anti-tick immunoglobulin, which is obtained from the blood of specially immunized donors. The greatest effect is achieved if it begins in the first 3 days from the onset of the disease. In a hospital, a spinal puncture is sometimes necessary before starting treatment. This procedure is absolutely safe for the patient, has certain indications and is needed not only to clarify the diagnosis, but also to select adequate treatment when changes in the cerebrospinal fluid are detected. Other means are also used, which are prescribed by the doctor in each specific case.

When to see a doctor

Patients often begin to take medications on their own to relieve headaches (a typical sign of tick-borne encephalitis). The persistence or slight decrease in the intensity of the headache after taking appropriate medications should be an indication for immediate consultation with a doctor, especially if the headache is combined with an increase in body temperature, and a few days ago there was an ixodid tick attached to the skin.

Complications of tick-borne encephalitis

Complications of tick-borne encephalitis are detected in 30–80% of those who have recovered from the disease, mostly flaccid paralysis of the upper extremities. Mortality ranges from 2% - with the European form to 20% - with the Far Eastern form. Death occurs within one week from the onset of the disease. Atypical forms of the disease (erased, polio-like), as well as the development of chronic carriage of the virus are possible.

Prevention of tick-borne encephalitis

To prevent tick-borne encephalitis, inactivated vaccines are used. Currently, four vaccines are available in Russia - two domestic (regular and concentrated) and two foreign.

Quick protection (literally the next day) can be achieved by a single injection of immunoglobulin, which protects for up to 1 month. Emergency prevention (that is, after a tick bite) can also be carried out using immunoglobulins. In Russia, two domestic drugs are available (from horse and human serum) and one imported one.

To prevent people from being affected by tick-borne encephalitis, before the start of the spring-summer season, areas and clothing are treated with special medical disinfectants.

What you need to know

The causative agent of tick-borne encephalitis is sensitive to environmental factors - it dies quite quickly at room temperature, when heated to 60º C (within 10–20 minutes), or when boiled (after two minutes). Rapidly destroyed by disinfectants. It can be stored in milk and dairy products for up to two months, but can survive for years when dried.

Is it possible for a healthy person to become infected from a sick person?

Several years ago, in Novosibirsk, scientists conducted a unique experiment on encephalitis infection with mice. Absolutely healthy females were placed in cages with virus-infected males. After a while, offspring appeared that were much weaker and smaller than those of healthy couples.

During the observation process, slow development of embryos was revealed. Some of the mice did not survive at all. During the research, scientists discovered an encephalitis virus in the cubs. The experiment caused a huge resonance in the scientific and medical community also because some people do not remember that they could ever be bitten by a tick. They also deny drinking milk. However, at the same time, they are carriers of the encephalitis virus.

The community of scientists who conducted these studies took the initiative that patients with encephalitis should be advised to abstain from sexual intercourse for a certain period. However, so far there have been no adherents of scientists among medical representatives.

Viral encephalitis is a pathology in which the appearance of diffuse and focal inflammation in the brain is observed. This disease is caused by a virus entering the body. It can have various clinical manifestations and consequences. Much depends on the state of the person’s immune system.

Features of the disease

The development of this type of brain inflammation occurs under the influence of a viral infection. Encephalitis is caused by different types of viruses. Most often, the lesion occurs as a result of herpes, childhood viruses similar to measles. The disease can also be caused by bites from infected mosquitoes. In this case, the membrane of the brain and the peripheral nerve are affected.

Pathology can develop in primary and secondary forms. In the first case, a viral disease occurs in the brain and spinal cord. With a secondary infection, other organs become infected, from which the virus spreads through the bloodstream throughout the body.

The causative agent of encephalitis can be transmitted by people and insects. Infection occurs:

by air;
sexually;
through the consumption of dairy products;
when touched.

Disease activity increases in the spring and summer. The development of enterovirus infections subsides at the end of summer.

Tick-borne encephalitis: carriers and carriers, infection, symptoms

Prepared by: MedWeb

Tick-borne encephalitis: carriers and carriers, infection, symptoms

Tick-borne encephalitis (Siberian, Far Eastern, spring-summer) is a natural focal (characteristic only for certain territories) viral disease with a predominant lesion of the human central nervous system. The virus is also dangerous for domestic animals, rodents, monkeys, and some birds.

Far Eastern tick-borne viral encephalitis, Central European tick-borne encephalitis, tick-borne encephalitis, viral diseases, fever

Carriers and vectors of tick-borne encephalitis

The reservoir of the virus in nature is many species of forest animals (chipmunks, voles, mice, hedgehogs, etc.), and its carriers are ixodid ticks, common in the forests of almost all European countries, in the European part of Russia and in Siberia. 5–6 days after bloodsucking on a sick animal, the virus penetrates all organs of the tick, concentrating in the genital apparatus, intestines and salivary glands, which explains the transmission of the virus to humans through a tick bite. Infection of a person can also occur by crushing and rubbing an attached tick. The tick can be brought from the forest with branches, on the fur of domestic animals, etc. Infection is also possible through consumption of infected raw goat and cow milk.

The virus remains in the tick throughout its entire life, that is, 2–4 years, and is transmitted from generation to generation, which makes ticks an independent natural reservoir of infection. Tick infestation varies from region to region and from season to season, ranging from 1% to 20%.

Incubation period of the disease

The incubation period of the disease averages 1.5–2 weeks, sometimes extending up to 3 weeks. The different lengths of the incubation period can be explained by the nature of the bite - the longer the tick is attached, the more viruses penetrate the body and the faster the disease will develop.

How does infection occur?

If a person is infected as a result of a tick bite or crush, the disease is characterized by one wave of fever caused by the penetration of the virus into the spinal cord and brain, and the development of inflammation of the latter (encephalitis itself). If infection occurs through milk (some experts even distinguish this route of infection and the corresponding form of the disease into a separate infection), the virus first penetrates all internal organs, causing the first wave of fever, and then reaches its final target - the central nervous system, and a second wave occurs. wave of fever.

Symptoms of infection

The disease occurs acutely and progresses over several days. The virus affects the cerebral cortex, motor neurons of the spinal cord and peripheral nerves. Initially, convulsions, paralysis of individual muscle groups or entire limbs are observed, and skin sensitivity is impaired. Later, when inflammation covers the entire brain, persistent headaches, vomiting occur, the patient loses consciousness (possibly a coma) or, conversely, psychomotor agitation develops with loss of orientation in time and space. Possible damage to the cardiovascular system (myocarditis, cardiovascular failure, arrhythmia), digestive organs (stool retention, liver enlargement), and spleen. All of these symptoms are observed against the background of general intoxication of the body with an increase in temperature to 39–40ºС. In a small percentage of cases, when only the spinal nerves are affected, the disease can occur as radiculitis (polyradiculoneuritis).

Reasons for development

Infection with viral encephalitis occurs if a person has had:

flu;
arbovirus;
measles;
rubella;
mumps;
herpes type 1 and 2;
Epstein-Barr disease;
varicella-zoster disease;
tick-borne encephalitis;
rabies;
cytomegalovirus infection.

Many people are interested in whether encephalitis is transmitted from person to person. In most cases, this option is possible. It is also transmitted by arthropods and animals suffering from rabies.

The main route of transmission of the disease is vector-borne. But they become infected through sexual, airborne, and fecal-oral routes.

A baby develops pathology if he becomes infected with herpes from his mother while passing through the birth canal. Also, enteroviruses can enter the fetus’ body during intrauterine development, causing inflammatory processes in the brain.

The risk of developing the disease is higher:

in children and elderly people;
in summer and spring;
in pregnant women;
with human immunodeficiency virus;
in those suffering from alcoholism;
while undergoing treatment for autoimmune diseases;
among residents of Asia, Africa, South America, and the Far East.

Under the influence of various pathogens, the pathological process in the brain can be accompanied by:

Hyperemia.
Inflammatory lesions of the walls of blood vessels.
Point or extensive hemorrhages.
Focal tissue death.
Fibrous changes in the membranes of the brain.
Formation of adhesions, nodes and cysts.
Swelling or softening of tissues.
Formation of infiltrates.
Dystrophic changes in neurons.
The appearance of diffuse lesions.
Development of destructive processes in glial cells.

Classification

Encephalitis of viral origin can be of different types, with lesions of white, gray and both substances at the same time.

If the pathological process has spread to other organs and systems, then the presence of:

Encephalomyelitis – damage to the spinal cord. As a result, the motor functions of the facial muscles are impaired, which subsequently spreads to the limbs. The patient cannot hold his head up; there is a decrease in the volume of the arms, neck, and shoulders.
Meningoencephalitis - the inflammatory process spreads to the membranes of the brain. In this case, an increase in body temperature is observed, a blood test shows a change in its composition. If the cells of this organ are affected, then disturbances of consciousness and motor functions occur, and the patient suffers from hallucinations.

Depending on the nature of origin, encephalitis can be:

Primary. Changes occur under the influence of the virus. Most often, serious complications and death occur with primary encephalitis.
Secondary. Inflammation develops as a result of infectious and allergic reactions, as well as autoimmune disorders.

Symptoms

When this type of virus appears, “classic” symptoms of increased body temperature and poor health are observed. Subsequently, such symptoms can influence the formation of negative processes of a neurological nature. The presence of headaches, ailments, photophobia, convulsions and even coma already indicate the presence of such a source of infection in the body.

The central nervous system is most susceptible to changes. Here there is deformation of the tissues and their covering with a membrane susceptible to infection. After the cells have undergone such a “procedure”, the incubation period of the disease begins.

Experts warn that it is considered the most dangerous in the stages of viral encephalitis. It is during this period that harmful bacteria are activated, spreading to the brain, spinal cord and cells adjacent to them.

If, at the time of infection with viral encephalitis, a person is already experiencing influenza, for example, then identifying the presence of infection becomes difficult. In this case, experts recommend that when the first symptoms appear, consult a doctor who will monitor the course of the disease.

At the same time, the progression of the disease itself occurs in quite different positions: from lightning fast to slow. Speaking about the intrauterine source of infection, organs such as the liver, kidneys, and lungs are affected.

In general, the symptoms vary in the following disorders: unsteady gait, lack of coordination, speech difficult to understand, nystagmus, sleep disturbance, partial memory loss, epileptic seizures, difficulty breathing.

Since such symptoms do not differ in their individuality, it is quite easy to confuse encephalitis with other diseases of similar characteristics. In this case, it is recommended not to self-medicate, but to get help from specialists as soon as possible who will help establish an accurate diagnosis and treatment methods.

How does the disease manifest itself?

Viral encephalitis in the initial stages of development has symptoms similar to the flu. The patient suffers from general malaise, high fever, runny nose, sore throat and sore throat.

Gradually these manifestations are supplemented:

headache;
nausea and vomiting;
increased sensitivity to light and sound;
impaired ability to navigate in space and time;
loss of consciousness;
hallucinations;
convulsions.

Viral encephalitis in infants is manifested by bulging of the fontanel.

Focal symptoms may also be observed, depending on which part of the brain was damaged. If the frontal or temporal lobe of the brain is inflamed, speech function is impaired. With occipital and temporal lesions, vision deteriorates.

If the cerebellum is affected by pathology, muscle tone decreases, tremors are observed and coordination of movements changes. In some cases, with encephalitis, cranial nerves are involved in the inflammatory process. This is accompanied by:

oculomotor and auditory disorders;
loss of taste and skin sensitivity;
speech and breathing disorders;
paralysis of the muscles of the tongue and larynx.

When infected during the prenatal period, the pathological process affects the lungs, kidneys, and liver.

Due to damage to the meninges, meningeal symptoms develop:

Rigidity of the neck muscles. The patient pulls his legs towards his stomach and throws back his head. This position is characteristic of meningitis.
Bend your knees while passively tilting your head.

The inflammatory disease can occur in moderate and acute forms.

The first development option is not safe, since in this case it can be fatal. In this case, manifestations characteristic of other diseases may occur, which complicate the diagnosis process. As a result, treatment is started at the wrong time and serious complications develop. This development of events is observed with encephalitis caused by the herpes virus. The person then suffers only from high fever, asthenic syndrome, and short-term convulsions.

Tick-borne encephalitis

Tick-borne encephalitis is a naturally focal transmissible (transmitted by ticks) viral infection, characterized by predominant damage to the central nervous system. The disease is characterized by polymorphism of clinical manifestations and severity of the course (from mild erased forms to severe progressive ones).

Currently, tick-borne encephalitis is registered in Siberia, the Far East, the Urals, Belarus, as well as in the central regions of the country.

Etiology . Tick-borne encephalitis virus (TBE) belongs to the genus Flavivirus (group B), which is part of the togavirus family of the ecological group of arboviruses. There are three types of the pathogen - the Far Eastern subspecies, the Central European subspecies and the causative agent of two-wave meningoencephalitis. The nucleocapsid of the virus contains single-stranded RNA. The virus survives for a long time at low temperatures (the optimal mode is minus 60°C and below), tolerates lyophilization well, and persists for many years in a dried state, but is quickly inactivated at room temperature. Boiling inactivates it after 2 minutes, and in hot milk at 60°C the virus dies after 20 minutes. Formalin, phenol, alcohol and other disinfectants, and ultraviolet radiation also have an inactivating effect.

Epidemiology. Tick-borne encephalitis belongs to the group of natural focal human diseases.

The main reservoir and carrier of the virus in nature are ixodid ticks - Ixodes persulcatus, Ixodes ricinus with transovarial transmission. Additional reservoirs of the virus are rodents (hare, hedgehog, chipmunk, field mouse), birds (thrush, goldfinch, redpoll, finch), and predators (wolf). The disease is characterized by a strict spring-summer seasonality of the disease. The main route of human infection is vector-borne transmission through tick bites. It is also possible to transmit the infection through the nutritional route when eating raw milk from goats and cows, as well as when crushing a tick at the time of its removal from the human body and, finally, through airborne droplets when working conditions in laboratories are violated. In case of alimentary infection, attention is drawn to the presence of family-group cases of the disease.

Pathogenesis. The infectious process develops as a result of the introduction of a neurotropic virus and its interaction with the human body. These relationships are determined by the route of introduction, the properties and dose of the pathogen, as well as the resistance and reactivity of the macroorganism. The tick-borne encephalitis virus enters the human body naturally through the skin when bitten by a tick or through the raw milk of domestic animals.

After sucking on a tick, the virus spreads hematogenously and quickly penetrates the brain, fixing itself here by cells. In parallel with the accumulation of the virus, inflammatory changes in the blood vessels and membranes of the brain develop. The correspondence of the site of the tick bite to the subsequent localization of segmental disorders indicates the possibility of a lymphogenous route of virus penetration into the central nervous system (CNS). In some cases, one or another path predominates, which is reflected in the clinical features of tick-borne encephalitis. The occurrence of meningeal and meningoencephalic syndromes corresponds to the hematogenous, and poliomyelitis and radiculoneuritic syndromes correspond to the lymphogenous route of spread of the virus. Invasion of the nervous system is also possible through the neural route through the centripetal spread of the virus through the olfactory tract. The rarity of damage to the lower extremities in tick-borne encephalitis does not correspond to the frequency of tick suction in the skin areas innervated by the lumbar and sacral segments of the spinal cord, which indicates the known tropism of the virus to the cells of the cervical segments and their analogues in the bulbar regions of the medulla oblongata.

Viremia in tick-borne encephalitis has a two-wave nature: short-term primary viremia, and then repeated (at the end of the incubation period), coinciding with the multiplication of the virus in the internal organs and its appearance in the central nervous system.

Long-term virus carriage is possible, which can be different in its manifestations and consequences: latent infection (the virus is integrated with the cell or exists in a defective form), persistent infection (the virus reproduces, but does not cause clinical manifestations), chronic infection (the virus reproduces and causes clinical manifestations with a recurrent, progressive or regressive course), slow infection (the virus reproduces after a long incubation period, causes clinical manifestations with steady progression, leading to death).

Symptoms and course. The following clinical forms of the disease are distinguished: 1) febrile; 2) meningeal; 3) meningoencephalitic; 4) poliomyelitis; 5) polyradiculoneuritis. In meningeal, meningoencephalitic, poliomyelitis, polyradiculoneuritic forms of tick-borne encephalitis and in cases with a two-wave course of the disease, hyperkinetic and epileptiform syndromes can be observed.

Regardless of the clinical form, patients experience general infectious manifestations of the disease, characterized by fever and other signs of general infectious intoxication syndrome. The incubation period of tick-borne encephalitis lasts on average 7-14 days with fluctuations from one day to 30 days. In a number of patients, the onset of the disease is preceded by a prodromal period, lasting 1-2 days and manifested by weakness, malaise, and weakness; Sometimes there is mild pain in the muscles of the neck and shoulder girdle, pain in the lumbar region in the form of aches and numbness, and headache.

The febrile form is characterized by a favorable course without visible damage to the nervous system and rapid recovery. This form accounts for approximately 1/3 of the total number of tick-borne encephalitis diseases. The febrile period lasts from several hours to several days (on average 3-5 days). Sometimes there is a two-wave fever. The onset is usually acute, without a prodromal period. A sudden rise in temperature to 38-39°C is accompanied by weakness, headache, and nausea. In rare cases, meningism may occur with this form of the disease. More often, there are no symptoms characterizing local damage to the brain and spinal cord. No changes were detected in the cerebrospinal fluid.

The meningeal form of tick-borne encephalitis is the most common. The initial manifestations of the disease in the meningeal form are almost no different from the febrile form. However, the signs of general infectious intoxication are much more pronounced. Rigidity of the neck muscles, Kernig's and Brudzinski's symptoms are determined. Meningeal syndrome is pronounced, the cerebrospinal fluid is transparent, sometimes slightly opalescent, its pressure is increased (200-350 mm water column). Laboratory examination of cerebrospinal fluid reveals moderate lymphocytic pleocytosis (100-600 cells per 1 μl, rarely more). In the first days of the disease, neutrophils sometimes predominate, which often completely disappear by the end of the first week of the disease. The increase in protein is observed inconsistently and usually does not exceed 1-2 g/l. Changes in the cerebrospinal fluid last a relatively long time (from 2-3 weeks to several months) and are not always accompanied by meningeal symptoms. The duration of fever is 7-14 days. Sometimes a two-wave course of this form of tick-borne encephalitis is observed. The outcome is always favorable.

The meningoencephalitic form is observed less frequently than the meningeal form - the national average is 15% (in the Far East up to 20-40%). It has a more severe course. Delusions, hallucinations, psychomotor agitation with loss of orientation in place and time are often observed. Epileptic seizures may develop. There are diffuse and focal meningoencephalitis. With diffuse meningoencephalitis, general cerebral disorders are expressed (profound disorders of consciousness, epileptic seizures up to status epilepticus) and scattered foci of organic brain damage in the form of pseudobulbar disorders (breathing disorders in the form of brady- or tachycardia, according to the Cheyne-Stokes, Kussmaul type, etc.), cardiac -vascular system, uneven deep reflexes, asymmetric pathological reflexes, central paresis of facial muscles and tongue muscles. With focal meningoencephalitis, capsular hemiparesis, paresis after Jacksonian seizures, central monoparesis, myoclonus, epileptic seizures, and, less commonly, subcortical and cerebellar syndromes quickly develop. In rare cases (as a consequence of a violation of the autonomic centers), gastric bleeding syndrome with hematemesis may develop. Characteristic are focal lesions of cranial nerves III, IV, V, VI pairs, somewhat more often VII, IX, X, XI and XII pairs. Later, Kozhevnikov epilepsy may develop, when general epileptic seizures with loss of consciousness appear against the background of constant hyperkinesis.

Poliomyelitis form. It is observed in almost 1/3 of patients. It is characterized by a prodromal period (1-2 days), during which general weakness and increased fatigue are noted. Then periodically occurring muscle twitching of a fibrillar or fascicular nature is detected, reflecting irritation of the cells of the anterior horns of the medulla oblongata and spinal cord. Suddenly, weakness may develop in any limb or a feeling of numbness may appear in it (in the future, severe motor disturbances often develop in these limbs). Subsequently, against the background of febrile fever (1-4 days of the first febrile wave or 1-3 days of the second febrile wave) and general cerebral symptoms, flaccid paresis of the cervicobrachial (cervicothoracic) localization develops, which can increase over several days , and sometimes up to 2 weeks. The symptoms described by A.G. Panov are observed: “head hanging down on the chest,” “proud posture,” “bent, stooped posture,” techniques of “throwing the arms of the body and throwing back the head.” Poliomyelitis disorders can be combined with conduction disorders, usually pyramidal: flaccid paresis of the arms and spastic paresis of the legs, combinations of amyotrophy and hyperflexion within one paretic limb. In the first days of the disease, patients with this form of tick-borne encephalitis often experience severe pain. The most typical localization of pain is in the neck muscles, especially along the back surface, in the area of the shoulders and arms. The increase in motor disorders continues for up to 7-12 days. At the end of the 2-3rd week of the disease, atrophy of the affected muscles develops.

Polyradiculoneuritic form. Characterized by damage to peripheral nerves and roots. Patients experience pain along the nerve trunks, paresthesia (feeling of “crawling goosebumps”, tingling). The symptoms of Lasseg and Wasserman are determined. Sensitivity disorders appear in the distal parts of the extremities of the polyneural type. Like other neuroinfections, tick-borne encephalitis can occur as Landry's ascending spinal palsy. Flaccid paralysis in these cases begins from the legs and spreads to the muscles of the torso and arms. The ascent can also begin from the muscles of the shoulder girdle, involving the cervical muscles and the caudal group of nuclei of the medulla oblongata.

Complications and damage to the nervous system. With all the above-described clinical forms of tick-borne encephalitis, epileptiform, hyperkinetic syndromes and some other signs of damage to the nervous system can be observed. This depends on the epidemic focus (western, eastern), on the method of infection (vector-borne, nutritional), on the condition of the person at the time of infection and on the methods of therapy.

Hyperkinetic syndrome is registered relatively often (in 1/4 of patients), and mainly in persons under 16 years of age. The syndrome is characterized by the appearance of spontaneous rhythmic contractions (myoclonus) in individual muscle groups of paretic limbs already in the acute period of the disease.

Progressive forms. From the moment of infection and subsequently, even after the acute period, the tick-borne encephalitis virus can persist in the central nervous system in an active form. In these cases, the infectious process does not end, but enters the phase of chronic (progressive) infection. Chronic infection with tick-borne encephalitis can occur in a latent form and manifest itself after several months and years under the influence of provoking factors (physical and mental trauma, early spa and physiotherapeutic treatment, abortion, etc.). The following types of progressive course are possible: primary and secondary progressive, and subacute course.

Diagnosis and differential diagnosis. The clinical and epidemiological diagnosis is correct. The patient’s stay in endemic areas, history of visits to the forest, the fact of tick suction, the season and onset of the disease, and consumption of raw goat’s milk are taken into account. Early diagnostic signs of the disease are headache, increasing in intensity as body temperature rises, nausea, vomiting, insomnia, and less commonly, drowsiness. Often headaches are accompanied by dizziness. In the clinical picture, attention is drawn to the pronounced lethargy of the patients and adynamia. On examination, hyperemia of the skin of the face, pharynx, and injection of blood vessels in the sclera and conjunctiva are noted. Sometimes small inflammatory erythema is observed on the skin at the site of tick suction. Subsequently, meningeal and encephalic symptoms develop.

The detection of moderate neutrophilic leukocytosis in peripheral blood and acceleration of ESR are of diagnostic importance. Laboratory confirmation of the diagnosis is an increase in antibody titer, detected using RSK, RTGA, RPGA, RDNA and neutralization reaction. A 4-fold increase in antibody titer is diagnostic. In the absence of an increase in antibody titer, patients are examined three times: in the first days of the disease, after 3-4 weeks and after 2-3 months from the onset of the disease. It should be borne in mind that in patients treated with immunoglobulin in the first 5-7 days of illness, there is a temporary inhibition of active immunogenesis, therefore it is necessary to carry out an additional serological study after 2-3 months. Using ELISA, antibodies to the tick-borne encephalitis virus are detected earlier and in higher serum dilutions than in RTGA and RSK, and also more often determine the change in the intensity of specific immunity, necessary to confirm the clinical diagnosis.

Treatment of patients with tick-borne encephalitis is carried out according to general principles, regardless of previous preventive vaccinations or the use of specific gamma globulin for preventive purposes. In the acute period of the disease, even in mild forms, patients should be prescribed bed rest until the symptoms of intoxication disappear. Almost complete restriction of movement, gentle transportation, and minimization of painful stimuli clearly improve the prognosis of the disease. An equally important role in treatment is the rational nutrition of patients. The diet is prescribed taking into account functional disorders of the stomach, intestines, and liver. Taking into account the vitamin imbalance observed in a number of patients, it is necessary to prescribe vitamins B and C. Ascorbic acid, which stimulates the function of the adrenal glands, as well as improves the antitoxic and pigment functions of the liver, should be administered in an amount of 300 to 1000 mg/day.

Etiotropic therapy consists of prescribing homologous gamma globulin titrated against the tick-borne encephalitis virus. The drug has a clear therapeutic effect, especially in moderate and severe cases of the disease. Gamma globulin is recommended to be administered 6 ml intramuscularly, daily for 3 days. The therapeutic effect occurs 12-24 hours after the administration of gamma globulin - body temperature drops to normal, the general condition of patients improves, headaches and meningeal symptoms decrease and sometimes completely disappear. The sooner gamma globulin is administered, the faster the therapeutic effect occurs. In recent years, serum immunoglobulin and homologous polyglobulin, which are obtained from the blood plasma of donors living in natural foci of the disease, have been used to treat tick-borne encephalitis. On the first day of treatment, serum immunoglobulin is recommended to be administered 2 times at intervals of 10-12 hours, 3 ml for mild cases, 6 ml for moderate cases and 12 ml for severe cases. In the next 2 days, the drug is prescribed 3 ml once intramuscularly. Homologous polyglobulin is administered intravenously in 60-100 ml doses. It is believed that antibodies neutralize the virus (1 ml of serum binds from 600 to 60,000 lethal doses of the virus), protect the cell from the virus by binding to its surface membrane receptors, and neutralize the virus inside the cell by penetrating it by binding to cytoplasmic receptors.

For specific antiviral treatment of tick-borne encephalitis, ribonuclease (RNase), an enzyme preparation prepared from the tissues of the pancreas of cattle, is also used. RNase inhibits the multiplication of the virus in the cells of the nervous system, penetrating the blood-brain barrier. Ribonuclease is recommended to be administered intramuscularly in an isotonic sodium chloride solution (the drug is diluted immediately before the injection) in a single dose of 30 mg after 4 hours. The first injection is performed after desensitization according to Bezredko. The daily dose of the enzyme introduced into the body is 180 mg. Treatment is continued for 4-5 days, which usually corresponds to the moment of normalization of body temperature.

A modern method of treating viral neuroinfections is the use of interferon preparations (reaferon, leukinferon, etc.), which can be administered intramuscularly, intravenously, endolumbarally and endolymphatically. It should be taken into account that large doses of interferon (IFN) 1-3-6o106 ME have an immunosuppressive property, and the resistance of cells to virus penetration is not directly proportional to IFN titers. Therefore, it is advisable to use relatively small doses of the drug, or to use interferon inducers (double-stranded RNA of phage 2, amiksin, comedon, etc.), which provide low titers of IFN and have immunomodulatory properties. Double-stranded phage RNA (larifan) is administered intramuscularly, 1 ml at an interval of 72 hours, 3 to 5 times. Amiksin in a dose of 0.15-0.3 g is prescribed orally with an interval of 48 hours from 5 to 10 times.

Pathogenetic therapy for febrile and meningeal forms of tick-borne encephalitis, as a rule, consists of measures aimed at reducing intoxication. For this purpose, oral and parenteral administration of fluid is carried out, taking into account the water-electrolyte balance and acid-base state.

In meningoencephalitic, poliomyelitis and polyradiculoneuritic forms of the disease, additional administration of glucocorticoids is mandatory. If the patient does not have bulbar disorders or disorders of consciousness, then prednisolone is used in tablets at the rate of 1.5-2 mg/kg per day. The drug is prescribed in equal doses in 4-6 doses over 5-6 days, then the dosage is gradually reduced (the total course of treatment is 10-14 days). At the same time, the patient is prescribed potassium salts and a gentle diet with sufficient protein content. For bulbar disorders and disorders of consciousness, prednisolone is administered parenterally, increasing the above dose by 4 times. In case of bulbar disorders, from the moment the first signs of respiratory failure appear, conditions must be provided for transferring the patient to mechanical ventilation. Lumbar puncture is contraindicated and can be performed only after removal of the bulbar devices. To combat hypoxia, it is advisable to systematically administer humidified oxygen through nasal catheters (20-30 minutes every hour), conduct hyperbaric oxygenation (10 sessions under pressure p 02-0.25 MPa), use neuroplegics and antihypoxants: intravenous administration of sodium hydroxybutyrate 50 mg/kg body weight per day or seduxen 20-30 mg/day. In addition, with psychomotor agitation, lytic mixtures can be used.

Central paralysis is treated with antispastic agents (mydocalm, baclofen, lioresal, etc.), drugs that improve microcirculation in blood vessels and trophism of the brain in lesions and cells that take on the function of dead structures (sermion, trental, cavinton, stugeron, nicotinic acid on glucose intravenously) in usual dosages. Seduxen, scutamil C, and sibazon have a muscle relaxant effect.

Convulsive syndrome requires long-term (4-6 months) use of antiepileptic drugs: for Jacksonian epilepsy - phenobarbital, hexamidine, benzonal or convulex; for generalized seizures - a combination of phenobarbital, definin, suxilep; for Kozhevnikov epilepsy - seduxen, iprazide or phenobarbital. For polymorphic seizures with a non-convulsive component, finlepsin, trimethin or pycnolepsin are added in standard doses.

Hyperkinetic syndrome is treated with nootropil or piracetam; in the acute period or for myoclonic seizures, sodium hydroxybutyrate and lithium are used intravenously. For throwing hyperkinesis, similar to Gilles de la Tourette's syndrome, a combination of Melleril, Elenium and Seduxen in normal dosages is recommended. For the polio form, live enterovirus vaccines can be used (in particular, polyvalent anti-polio vaccine, 1 ml per tongue three times with an interval of 1-2 weeks). As a result, interferon induction is enhanced, phagocytosis and functional activity of immune incompetent cells are stimulated.

Forecast. Favorable for meningeal and febrile forms. With meningoencephalitis, poliomyelitis and polyradiculoneuritis it is significantly worse. Lethal outcomes up to 25-30%. In convalescents, pronounced organic changes in the central nervous system (convulsive syndromes, muscle atrophy, signs of dementia, etc.) persist for a long time (up to 1-2 years, and sometimes for life).

Prevention and measures in the outbreak. Killing and preventing tick bites. As a specific prevention, vaccination is used, which is the most reliable preventive measure.

During the first 24 hours after tick ingestion - emergency prevention: donor immunoglobulin (titer 1:80 and above) intramuscularly in a dose of 1.5 ml for children under 12 years old, 2 ml - from 12 to 16 years old, 3 ml - for persons aged 16 years old and older.

Nonspecific preventive measures are limited to preventing ticks from being sucked on, as well as their early removal.

Avoid visiting tick habitats (forest biotopes with tall grass and bushes) in April-July.
Use repellents containing DEET or permethrin.
You should wear clothes with long sleeves and trouser legs without holes or holes; it is advisable to tuck the trouser legs into long socks, and the shirt into trousers. Hair should be hidden under a hat. To make ticks easier to spot, it is preferable to wear light-colored clothing.
While in the forest, it is recommended to regularly inspect clothing and monitor exposed skin (neck, wrists).
Upon returning from the forest, clothing and body are examined.
Since the larval forms of mites are very small, they may not be noticeable on clothing. To prevent them from being sucked in, it is recommended to wash clothes in hot water.
If an attached tick is found, it should be removed immediately. The sooner the tick is removed, the less likely it is to become infected. You can remove the tick with nail tweezers or thread, tying it around the head of the parasite. The tick is removed using rocking and twisting movements. Avoid crushing the tick! The wound can be treated with any disinfectant solution (chlorhexidine, iodine solution, alcohol, etc.).

Establishing diagnosis

If the disease is severe, then the diagnosis is combined with symptomatic therapy, which can alleviate the patient’s condition, improve breathing, and relieve swelling from the brain tissue.

Diagnosis begins with collecting anamnesis and analyzing the clinical picture. After this, a neurological examination is performed to determine the level of consciousness.

Clinical and biochemical studies cannot determine the presence of specific changes in the body.

The main diagnostic method is lumbar puncture. During this procedure, cerebrospinal fluid is taken and the quantity of leukocytes, red blood cells, protein, and glucose is checked. In case of encephalitis, its opacity is observed. In some cases, analysis reveals the pathogen that provoked the pathological process.

It is important for the doctor to make sure that there are no signs of increased intracranial pressure, since under such conditions it is prohibited to perform a lumbar puncture. The procedure may cause complications.

To identify the characteristics of lesions in the brain and exclude other diseases, computed tomography and magnetic resonance imaging are performed.

Also, during the examination, it is imperative to determine whether the person suffers from pathologies:

It is important to determine susceptibility to hemorrhage and whether the patient has suffered a traumatic brain injury.

All of these conditions require proper medical care and can pose serious health risks.

Encephalitis - inflammation of the brain of various etiologies - basic information about the disease and its treatment

Encephalitis is an inflammatory lesion of the brain associated with infection, autoimmune or tumor damage to the nervous tissue. The disease occurs acutely or chronically, which depends on the characteristics of the human body and the cause of the development of the pathology. Symptoms include intoxication phenomena, as well as focal neurological symptoms associated with damage to specific areas of the central nervous system.

If signs of illness appear, you should immediately seek medical help at a medical facility. The pathology can progress rapidly if left untreated and lead to serious consequences, including death.

infectious agents – tick-borne encephalitis virus, meningococcal infection, fungal microorganisms, etc.;
autoimmune reactions that often develop after infections, for example, chickenpox (a characteristic sign of autoimmunity is demyelination of nerve fibers);
paraneoplastic processes associated with the presence of a malignant neoplasm in the body.

Who can get infected?

Particular risk groups include newborns and the elderly. Those who are in areas where mosquitoes or ticks live can also become infected. Weak immunity is also one of the possible causes of infection, as well as long-term use of antibacterial or chemotherapy drugs.

There is such a thing as “countries endemic for encephalitis.” Infectious disease specialists and epidemiologists use this formulation when dealing with people who have returned from tropical countries with a high risk of morbidity. And of course, we cannot help but remember the “anti-vaxxers” who are at particular risk because they refuse to vaccinate their children against measles, mumps, rubella and other “childhood” infectious diseases.

It should be borne in mind that more than 90% of patients with encephalitis have symptoms similar to influenza. In the presence of both meningitis and encephalitis at the same time, a person experiences:

Epidemic

Another name is lethargic. Diagnosed in both children and adults. Symptoms manifest themselves in a sharp increase in temperature, intense headaches, and pain in the joint tissue.

The patient experiences confusion, delusions, and hallucinations. Later, squint, difficulty breathing, and excessive sweating are added.

You can learn about the causes of increased intracranial pressure in adults here.

Treatment

The encephalitis virus does not require specific therapy. The only exception is brain damage due to herpes or chickenpox. These cases can be easily eliminated only with Acyclovir.

The first stage is symptomatic therapy. It includes:

use of resuscitation aid in the form of artificial ventilation, cardiotropic drugs;
fluid administration;
prescribing corticoids to eliminate the inflammatory process;
ensuring oxygen supply if signs of hypoxia are observed;
the use of diuretics, which accelerate the elimination of toxic substances and relieve cerebral edema;
infusion therapy if severe poisoning occurs;
use of antihistamines and antipyretics;
prescribing antibacterial agents to prevent secondary infection;
use of anticonvulsant treatment if there are seizures.

After suppressing the acute period, methods are selected to restore the brain and the entire body. They resort to using:

nootropic drugs and B vitamins;
levodopa drugs if you are concerned about the manifestations of Parkinson's disease;
anticonvulsants;
neuroleptics and tranquilizers;
antidepressants.

You can easily become infected with encephalitis from a person. This is a dangerous pathology, so it is important to limit the patient’s contact with healthy people. For those who are interested in whether encephalitis is sexually transmitted, the answer is that the chances of infection are very high.

Kinds

There are several types of viral encephalitis. Depending on the degree of damage to brain cells and the body, the form of the disease and extent, as well as the cause of the infection.

Thus, there are more than 20 types of viral encephalitis, and the main ones are the following:

Economo - transmitted by airborne droplets, affects all age categories. In this case, high body temperature, dizziness accompanied by pain, joint weakness, dysfunction of respiratory tract rhythms, sleep disturbance, and high sweating are relevant.
Tick-borne - drooping upper eyelid, convulsions, impaired eye movements, insomnia, fever. Occurs after a tick bite.
Japanese - symptoms of ARVI, nausea and vomiting, weakness of the whole body, impaired consciousness. The carrier is both humans and birds and insects.
Influenza - accompanied directly by the flu. A particularly dangerous type of encephalitis, in which coma and epileptic seizures are often observed.
Herpetic - the lesion is the white matter of the brain. Movements are meaningless, mild memory loss, disorientation, sleep disturbance, appetite disturbance, and mild personality disorder are possible. The infection appears slowly.
Post-vaccination - most often provoked by a reaction to the vaccine;
Measles - manifests itself a few days after measles, accompanied by either hyperactivity up to seizures, or, conversely, excessive weakness, coma.
Bacterial - rare, the main symptom is fever, it has a significant effect on the development of diseases such as pneumonia, myocarditis, monocytosis.
With chickenpox , it primarily affects the nervous system, leading to paralysis of the limbs.

Possible complications and prognosis

The consequences of pathology can be different. This is influenced by the pathogen, the state of the immune system and the age of the patient, the characteristics of the course of the disease, the correctness and timeliness of therapy.

The most dangerous is encephalitis caused by the herpes virus. In everyone who has suffered such a disease, it causes neurological disorders.

Most often, after an inflammatory process in the brain, a person suffers from:

Headaches and dizziness.
Sleep disorders.
Oculomotor disorders.
Clinical depression.
Memory impairment or loss.
Difficulty concentrating.
Epilepsy attacks.
Dementia.
Developmental delays if the child suffered the disease.
Fatigue and constant weakness.
Urinary incontinence.
Partial or complete paralysis.
Schizophrenia.
Coordination problems.
Irritability, aggressiveness, tearfulness, increased excitability.

Since encephalitis is transmitted from person to person, it is important to consult a doctor at the first symptoms to protect your loved ones from infection. You can protect yourself from some types of disease through vaccination. It is also important to avoid catching the flu. To do this, during epidemics you should not visit public places.

Encephalitis is a disease that affects the brain and leads to inflammation. It is important for everyone to know how encephalitis is transmitted and what needs to be done to get rid of it.

Among the factors causing encephalitis, there are several:

toxic;
allergic;
infectious;
infectious-allergic.

The disease develops either due to viruses - neuroinfections, or manifests itself as a result of other diseases.

Encephalitis can be divided into 2 types: primary and secondary. The latter can occur against the background of such illnesses as influenza, measles, osteomyelitis, rubella, toxoplasmosis, etc.

As a rule, it is most often found in children. But primary, or independent, encephalitis is more common, divided into several types:

enterovirus;
herpetic;
mosquito;
epidemic;
tick-borne

The latter, transmitted through a tick bite, is the most famous.

Types and methods of transmission of encephalitis

Tick-borne encephalitis can be transmitted not only through the bite of an infected tick. It can also be contracted by drinking raw milk from sick cows or goats, where the virus gets along well. This is extremely dangerous, since the whole family is immediately exposed to the disease. If milk is boiled, it is not dangerous. The body of warm-blooded animals - rodents, birds, livestock - is a favorable environment for the reproduction of the virus. Although the animals themselves do not suffer from the disease.

Most often, the virus is carried by ticks, in which it persists until the end of their lives. When an insect bites, it releases infection into the bloodstream.

The longer the bite lasts, the more the person’s blood becomes infected.

It is very important to get rid of the tick as early as possible, because the more infection that enters the body, the more severe the disease will be. Do not forget that viral tick-borne encephalitis is a seasonal disease and the likelihood of contracting it increases in May-June and August-September. However, there is also a certain risk in other warm seasons. The tick-borne virus is not transmitted from person to person, so you should not avoid contact with an infected person.

There are other types of encephalitis, for example, epidemic, which is extremely rare today. However, it can occur due to an airborne virus. This type of disease is typical for all ages. Another type is herpetic, which occurs as a result of the penetration of the herpes virus into the human body. This is one of the most severe types of encephalitis.

It happened that patients died within the first 24 hours, although favorable outcomes were also possible. Japanese encephalitis, which is transmitted through mosquito bites, is no less dangerous.

In 50% of cases, the person dies within a week after the first symptom appears.

There are quite a few types of this disease, and all of them are dangerous. Some appear for unknown reasons, others affect the body against the background of various diseases: influenza, measles, chickenpox and even the common cold.

Viral encephalitis

Muscle pain
Joint pain
Bulging and tension of the fontanel
Hallucinations
Dizziness
Double vision
Fever
Disturbance in sleep and wakefulness
Impaired consciousness
Inability to hold head up
Tearfulness
Fever
Loss of appetite
Vomit
Photophobia
Stiffness in movement
Reduced skin sensitivity
Muscle spasm
Convulsions
Epileptic seizures

Viral encephalitis is an inflammatory process of the brain, which is accompanied by damage to the membranes of the spinal cord and the peripheral nervous system. The disease is caused by the penetration of viral microorganisms into this area. In most cases, the cause is the herpes virus, as well as diseases characteristic only of children, in particular measles, as well as a range of bacteria that are transmitted through insect bites. There are several types of encephalitis - primary and secondary. Often the encephalitis virus does not live long, but can nevertheless become life-threatening.

Etiology
Varieties
Symptoms
Complications
Diagnostics
Treatment
Prevention

Clinical manifestation depends on the type of virus and the state of immunity. The main symptoms are signs of intoxication of the body, convulsions, photophobia. The complex of diagnostic measures includes an instrumental examination of the patient, lumbar puncture and laboratory studies of the cerebrospinal fluid. Treatment of the disease is medicinal. Without timely treatment, serious consequences develop that can cause death.

newborns and elderly people;
persons with a weak immune system;
untimely or complete lack of vaccination in children against the above diseases;
autoimmune disorders;
living or traveling in areas with a high prevalence of this disease.

Types of encephalitis, causative agent

There are several criteria for classifying encephalitis. Let's look at each of them.

The course of the disease is acute, subacute and chronic encephalitis.

By location of the lesion:

Leukoencephalitis - affects the white matter of the brain;
Polioencephalitis – affects the gray matter;
Panencephalitis - both gray and white matter are affected;
Encephalomyelitis - symptoms affect some parts of the spinal cord.

In addition, depending on the location in a particular part of the brain, hemispheric, brainstem, cerebellar, diencephalic and mesencephalic encephalitis are distinguished. The disease is also capable of spreading differently in tissues, resulting in focal and diffuse encephalitis.

However, the main demarcation of types of disease occurs on the basis of its etiology and pathogenesis.

Epidemic encephalitis Economo (lethargic encephalitis A)

The disease is caused by a virus still unknown to science. Infection occurs from one person to another through airborne droplets; There is also a vertical or contact transmission route. This type is sometimes called sleeping sickness. It refers to the primary types of encephalitis, i.e. develops as a separate, independent disease.

Tick-borne encephalitis

The most common disease occurs after the bite of an infected tick. It is seasonal - found in spring and summer, i.e. during the active life of ticks. Some areas of the world are more dangerous due to the greater prevalence of these insects - usually there are higher rates of encephalitis. Encephalitis is carried by so-called ixodid ticks, but it can also be carried by mice, other rodents, birds, wild animals, cows, and goats. The manifestation of the disease begins after an incubation period, which lasts from 7 to 21 days, and in some cases it is longer - up to 35 days.

Influenza (toxic-hemorrhagic) encephalitis

Unlike the first two, this type of disease is classified as secondary encephalitis. It is viral in nature and develops as a complication of the flu. In addition, viral encephalitis can cause other diseases - for example, chickenpox, measles, herpes, rubella.

Measles encephalitis (encephalomyelitis)

Symptoms of the disease

The disease manifests itself in different ways, the symptoms depend on a large number of different factors. However, there are still several manifestations characteristic of this disease.

Like the vast majority of infectious diseases, encephalitis is accompanied by an increase in temperature.

The functioning of the gastrointestinal tract is disrupted, so the patient may develop diarrhea or vomiting. It is possible that problems with the upper respiratory tract may occur. Encephalitis is accompanied by impaired consciousness, weakness may appear throughout the body, epileptic seizures are common, and a fear of light begins.

Sometimes encephalitis, on the contrary, causes psychomotor agitation, for example, fussiness or restlessness. In this case, psychosensory disorders are possible, in which the shape of objects or their perception is disrupted. Objects may appear misshapen or smaller. The same goes for your own body.

The patient feels as if he has grown so much that he does not fit into the bed, and at the same time he cannot lift his head from the pillow. Objects begin to change colors to blue or red. Things that are nearby are perceived as if they were at a great distance.

All of the above psychosensory disorders manifest themselves due to the strong influence of the virus on the brain. But sometimes encephalitis is practically asymptomatic. Thus, the patient may experience a slight headache or dizziness. In some cases, the disease manifests itself as an acute respiratory viral infection or a stomach infection. The most dangerous form of this disease is fulminant encephalitis. As you can guess from the name, it proceeds extremely quickly. A person often falls into a coma within a few hours. As a rule, death occurs from acute heart failure.

Symptoms of tick-borne viral encephalitis

The acute onset of the disease is 7–10 days after the tick bite. Against the background of high fever (up to 39–40 °C), intense headache and vomiting occur for 1–2 days. Meningeal signs appear 2–4 days after the onset of the disease. Patients are concerned about muscle pain (70%), weakness in the arms and neck muscles (80%), difficulty swallowing (40%), and speech impairment (35%).

Incidence of tick-borne encephalitis in the Russian Federation per 100 thousand people

An objective examination reveals hyperthermia, severe cerebral syndrome, hyperemia of the face, neck, meningeal signs, flaccid paralysis of the muscles of the shoulder girdle, proximal parts of the upper extremities (80%), and the “dangling head” symptom (30%). Muscle atrophy is noted in the neck, in the shoulder girdle, proximal parts of the upper extremities (60%), impaired consciousness, bulbar syndrome (35%).

1 - “dangling head” symptom; 2 and 3 - atrophy of the muscles of the shoulder girdle

Treatment of encephalitis

If symptoms of encephalitis appear, the infected person should be hospitalized immediately. The patient is placed in an infectious diseases or neurological department and closely monitored.

In the treatment of tick-borne or Japanese encephalitis, donor gamma globulin and other antiviral drugs, including Interferon, are used.

The patient must observe strict bed rest until the symptoms of the disease completely disappear. By limiting movement and carefully transporting the infected person, the chances of a favorable outcome increase. Do not forget about the diet, which is prescribed taking into account the effect of the disease on the gastrointestinal tract and liver.

Mandatory procedures are detoxification and dehydration therapy. The patient is given ascorbic acid, which well stimulates the function of the adrenal glands and improves the antitoxic and pigment functions of the liver. If encephalitis has led to cerebral edema, the patient is prescribed corticosteroids. The patient needs artificial ventilation in cases where the disease affects the upper respiratory tract.

When convulsions begin, the patient is given analgesics and massage is prescribed.

However, the main weapon in the fight against the disease is gamma globulin. After 12 - 24 hours, the patient becomes significantly better, body temperature drops to normal, and the general condition of the body returns to normal. Headache and dizziness decrease or disappear altogether. The sooner gamma globulin is administered, the faster the therapeutic effect occurs.

Recently, serum immunoglobulin, which doctors obtain from donor blood plasma, is increasingly being used.

Antibodies can quickly neutralize the virus. 1 ml of the drug neutralizes up to 60,000 lethal doses of the virus.

The serum binds to the surface membrane receptors of the cell, penetrating it and completely neutralizing the virus.

Treatment of tick-borne viral encephalitis

Treatment is prescribed only after confirmation of the diagnosis by a medical specialist. Symptomatic therapy, detoxification, maintaining water and electrolyte balance, and dehydration are indicated. Early rehabilitation is desirable.

Essential drugs

There are contraindications. Specialist consultation is required.

Human immunoglobulin against tick-borne encephalitis (specific human immunoglobulin). Dosage regimen: in the first days, 3 ml intramuscularly at intervals of 10-12 hours (until the temperature drops).
Furosemide (diuretic). Dosage regimen: intramuscularly or intravenously (slow stream) 20-60 mg 1-2 times a day, if necessary, the dose can be increased to 120 mg. The drug is administered for 7-10 days or more, and then the drug is taken orally.
Reamberin (detoxifying agent). Dosage regimen: intravenous drip at a rate of up to 90 drops/min. (1–4.5 ml/min.) 400-800 ml/day. The rate of drug administration and dosage are determined in accordance with the severity of the patient. The course of drug administration is up to 11 days.
Ribavirin (antiviral drug). Dosage regimen: orally, without chewing and with water, along with meals, 0.8-1.2 g/day. in 2 doses (morning and evening).
Wobenzym (anti-inflammatory, immunomodulatory agent). Dosage regimen: orally, no less than 30 minutes. before meals or 2 hours after meals, washed down with water in a dosage of 3 tablets. 3 times a day. The course of treatment is from 2 to 5 weeks.

Precautions and prevention

If you decide to go outdoors but are afraid of encephalitis ticks, you should follow a few simple precautions to reduce the risk of infection:

Get a preventive vaccination at the hospital. It’s better to take care of this in advance, about 3 weeks before you go on vacation.
If you are going to a mountainous, wooded area, wear light-colored clothing if possible, as ticks are easier to spot on them. To prevent insects from getting under your clothes, tuck your shirt or T-shirt into your trousers and tuck them into your socks. For footwear, it is better to choose boots. Place a scarf on your head, tucking it under your jacket. Remember: a tick always crawls from bottom to top.
Be sure to use chemical protection products. If you are traveling overnight, treat not only your clothes, but also your sleeping bag with a protective drug. You can also apply a protective repellent to bare areas of the body, for example, Medilis-comfort, which protects not only from ticks, but also from mosquitoes, as well as other blood-sucking insects.
If you find a tick, do not crush it with your finger under any circumstances, as the encephalitis virus can enter the body through microcracks in the skin, and you risk becoming infected.