What is Tick-borne Encephalitis in Children?
Tick-borne encephalitis is also called spring-summer or taiga. This is a natural focal viral disease (the causative agent of which circulates among animals), in which there is a defeat of the central nervous system, and in which cerebral, meningeal and focal symptoms are manifested.
Tick-borne encephalitis in children is:
- tick-borne encephalitis
- Far Eastern viral encephalitis (also called Russian spring-summer encephalitis)
- tick-borne viral encephalitis, unspecified
- another tick-borne viral encephalitis.
The disease is called natural focal when the pathogen is found among animals and insects and spreads by them. Tick-borne encephalitis refers to such diseases. In Russia, the foci of this disease are located in the taiga in the Far East, Siberia, the Urals, and in some areas of the European part of the country.
Ixodid ticks are the main guardians and carriers of infection. On Vvostok it is Ixodes persulcatus, and in the west it is Ixodes ricirtus. In some parts of the disease, other tick species can cause the disease. These insects contain the causative agent of the disease for life, lay infected eggs, from which then infected ticks appear (transovarial transmission of infection).
Ticks in the wild infect rodents, hedgehogs, chipmunks and other animals and birds. Infected animals from that moment can also spread the infection. A person becomes infected by being bitten by an infected tick. Together with tick saliva, the virus enters the baby’s blood (and the likelihood of infection increases when the infectious tick is crushed). The virus can be brought from the bite to the mucosa.
In some areas, cattle may participate in the infection chain, whose meat and milk are then consumed by the person along with the infection.
An increase in the incidence is observed in spring and summer, as It is at these times of the year that ixodid ticks are most active. The incidence of tick-borne encephalitis among children is lower than among adults, but still there. There are also epidemics in rest camps, which are located next to tick habitats (forests). Children 7-14 years old are most susceptible to the disease among children.
Causes of Tick-borne Encephalitis in Children
The causative agent of the disease belongs to the genus flaviviruses. The spherical virion has a diameter of 40 to 50 nm. The virus contains RNA and can multiply in many tissue cultures. Among animals tested in laboratories, hamsters, white mice, monkeys and cotton rats are most susceptible to the virus.
Tick-borne encephalitis can infect pets. The virus can be killed with ordinary disinfectants, by raising the temperature of the environment. The virus in its dried form can retain its properties for months and even years.
Pathogenesis during Tick-borne Encephalitis in Children
The primary locations of the virus are the skin, subcutaneous tissue, and the gastrointestinal tract. With the help of lymph and blood, the virus spreads throughout the body, even entering the central nervous system. There, it causes damage to the gray matter of the brain and spinal cord. Hard and soft meninges are also affected. Intoxication is manifested, damage to the visceral organs, for example, the adrenal glands, spleen, etc. occurs. The cardiovascular system that the virus can affect is also at risk.
The virus causes the greatest morphological changes in the central nervous system. Puffiness and plethora of the soft and hard shells of the brain are recorded. In the section, the substance of the brain and spinal cord is flabby, swollen, with point hemorrhages. Histological examination allows you to determine disseminated perivascular infiltrates, degenerative-dystrophic changes in nerve cells (even complete necrosis is likely), etc.
Significant changes occur in the brain stem, the anterior horns of the spinal cord, the hypothalamic region, the optic tubercle and in the cerebellum.
Inflammation can also be in other organs of the child.