Tick-borne encephalitis

Tick-borne encephalitis is an acute viral disease characterized by the damage to the gray matter of the brain and spinal cord. The reservoir and source of infection are wild animals (mainly rodents) and ixodid mites. Infection is possible not only when the tick is sucked, but also when you take milk from infected goats.

Etiology, pathogenesis. The causative agent is related to arboviruses. Gates infection-skin integuments (when sucking on ticks) or mucous membrane of the digestive tract (with alimentary infection). The virus hematogenously penetrates into the central nervous system, causes the most pronounced changes in the nerve cells of the anterior horns of the cervical spinal cord and in the nuclei of the medulla oblongata.

Symptoms, course. The incubation period lasts from 8 to 23 days (usually 7-14 days). The disease begins acutely: chills, severe headache, weakness. In the first days only general toxic symptoms are noted. Characteristic changes in the nervous system occur only on the 3rd-4th day of the disease. By the nature of the defeat of the nervous system, the following syndromes can be identified: meningeal, poliomyelitis, polyradiculoneuritis, and also manifestations of diffuse and focal encephalitis. Light forms of tick-borne encephalitis can occur in the form of short-term febrile illnesses without pronounced signs of damage to the nervous system. Middle-severe and severe forms of the disease occur with the predominance of a syndrome. In individual patients (from 1 to 14%) the disease can go into a chronic form. After the encephalitis, persistent consequences in the form of flaccid paralysis of the muscles of the neck, shoulder girdle, and kozhevnik epilepsy can remain. For diagnosis, the epidemiological prerequisites (seasonality, tick sucking, stay in endemic area), characteristic lesions of the nervous system matter. To confirm the diagnosis, serological reactions are used (DSC, RNGA).

Treatment. Strict bed rest: 7-10 days for mild forms, 2 to 3 weeks for moderate ones, and much longer for heavy ones. In the first 3 days of treatment, antiancephalitic gamma globulin is injected at 3-6 ml IM. Oxygenotherapy, vitamins. With the development of encephalitis appoint prednisone 40-60 mg, diuretics. In the period of convalescence in the presence of paresis and paralysis, orthopedic treatment is performed.

The prognosis with modern methods of treatment has significantly improved. Individual patients may have persistent disability as a result of residual effects of nervous system damage.

Prevention. When sucking a tick in a dysfunctional encephalitis terrain, it is necessary to inject anti-encephalitic gamma globulin (3 ml adults, children 1.5-2 ml). According to the indications, preventive vaccination is carried out.