Tick-borne encephalitis tick: how it differs from an ordinary tick and where it lives

"Encephalitis tick" is a colloquial name, not a separate species: it refers to a tick infected with the tick-borne encephalitis virus. It looks no different from an ordinary tick, so the only way to know about the risk is to understand where you are and what happens after a bite.

What an encephalitis tick means

Tick-borne encephalitis is a viral infection transmitted by the bite of ixodid ticks. Statistically, six ticks out of a hundred carry the virus. In itself, an "encephalitis" tick is an ordinary virus-carrying tick, not a special species.

Encephalitis tick and ordinary tick: are there differences

It is impossible to distinguish an infected tick from an uninfected one by appearance. Ticks can be very small and hard to notice; after feeding on blood, they grow larger. Infection is also possible if the tick's biological fluids get into a wound or onto mucous membranes — for example, if you crush it with your hands.

Where the encephalitis tick lives

Ticks live in forest and grassy areas and are also found in some parks and gardens. Virus-infected ticks are widespread in most of Europe, in Russia, and in parts of China and Japan. The disease has been identified in 27 European countries; the highest annual incidence — 5–18.6 cases per 100,000 population — is in the Czech Republic, the Baltic countries, and Slovenia. Traditional areas in Russia are Siberia, the Urals, and the Far East; cases also occur in the central belt, the Northwestern region, and the Volga region.

Probability of infection after a bite

The risk of becoming ill after a bite is low. Even if the tick is infected, between 2 and 6% of bitten people may become ill — depending on the region. In most infected people, the virus causes no symptoms. A rare route of transmission is raw (unpasteurized) milk and dairy products; it accounts for 2 to 5% of registered cases.

Why tick-borne encephalitis is dangerous

In some people, about a week after the bite, flu-like symptoms appear: high fever, chills, fatigue, headache, aching, nausea. They usually resolve on their own. In a few people, the infection spreads to the brain after several days or weeks — this is life-threatening. Then severe headache with neck stiffness, pain when looking at bright light, seizures, behavioral changes, confusion, slurred speech, weakness or loss of movement in part of the body are possible. A doctor may order imaging (CT or MRI), EEG, and blood and cerebrospinal fluid tests.

When to see a doctor after a bite

If you have been bitten by a tick or have visited places where they occur in the past month and flu-like symptoms or a round rash appear, an urgent medical consultation is needed. Tell the specialist about the bite or a suspected bite.

• high fever, chills
• headache, muscle aching
• nausea
• round rash
• fatigue

In itself, this is not a reason to call an ambulance; 103 or 112 — if neck stiffness and severe headache appear, pain when looking at bright light, seizures, behavioral changes, confusion or slurred speech, weakness or loss of movement in part of the body, including drooping of one side of the face.

This material is for reference: it does not replace a doctor's consultation, which will assess your situation individually.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer