Tick-borne encephalitis is a serious disease that is closely associated with the Lyme disease. These two completely different diseases have one common factor – the tick.
The cause of the disease is a virus carriers and the tick is only its carrier. The virus gets into our body by the bite of an infected tick. Not all ticks are infected with the virus and not every bite causes the infection. After entering a human body, the virus multiplies and attacks the tissues and organs of our body. Unfortunately, brain tissue is a common target. Rarely, the infection can be transmitted from other infected animals, for example there was reported a tick-borne encephalitis infection from milk of infected goats.
The symptoms of the disease usually appear in about 1-2 weeks after the infection. The first symptoms are vague and do not differ too much from other viral infections – fever, headache, muscle pain and joint pain. The most visible symptoms occur when the virus attack the nervous system. Inflammation of the brain tissue (encephalitis) manifests with a strong headache, nausea, and vomiting. Affection of the brain meninges causes occurrence of meningeal symptoms (such as the stiff neck). A serious and frequently long-term consequence is muscle paralysis, typically of the upper extremities. The paralysis may persist even after the withdrawal of the infection and turn a previously healthy patient disabled.
The diagnosis is probable in a person with the above-mentioned symptoms who has a positive recent history of a tick bite. Examination of the cerebrospinal fluid (acquired by a lumbar puncture) confirms viral inflammation and serological examination made out of a blood sample may find antibodies against the tick-borne encephalitis virus, thus confirming the diagnosis.
As the disease is caused by a virus, our therapeutic options are very limited. The treatment of patients is therefore mostly symptomatic (bed rest, hydration, fever treatment and pain therapy). If there is any lasting motoric disorder, long-term rehabilitation is essential.