Tick borne encephalitis

Tick-borne encephalitis is an inflammatory disease of the brain caused by Flavivirus, a family of Flaviviridae, which are positive single-stranded RNA viruses. The virus causing tick-borne encephalitis is divided into three subtypes. These are the Western European subtype (which occurs in Europe and its vector is the tick Ixodes ricinus), the Siberian subtype (its vector is Ixodes persulcatus) and the Far Eastern subtype (its vector is Ixodes persulcatus). The Asian virus has a much worse course than the European one. In addition to tick bites, one can be infected by drinking unpasteurized milk and consuming uncooked dairy products.

The symptoms usually occur within one to two weeks after infection. Initially, it manifests itself as a non-specific common flu. Symptoms are fever, headache, muscle and joint pain, neck stiffness, nausea and fatigue. At this stage, the virus multiplies in the body. After a few days, the symptoms disappear, followed by one to two weeks without symptoms. In some people, the infection ends, in others the disease goes into a second, severe phase that lasts two to three weeks and can leave lasting consequences. At this stage of the disease, the central nervous system is affected, manifested by symptoms such as persistent headache, vomiting, nerve paralysis, tremor, dizziness, sleep disturbance and impaired ability of orientation. Mortality rates are 1-2%, when the virus attacks the brain centers responsible for breathing and heart contractions. In 10% of patients who were fortunate and had a second phase of the disease without permanent sequelae, a so-called postencephalitis syndrome occurs, which can last for many months. Fortunately, it is a reversible condition and the patient is completely healed.

Tick-borne encephalitis is a disease for which there are is effective cure. Therefore, vaccination is great prevention, especially in areas of high tick infestation.