Tick-borne Encephalitis

Transmitted by Ixodes ricinus ticks active March–November (peak May–July). Rare cases also occur after consuming unpasteurised dairy products from infected goats, sheep, or cows. Not transmitted person-to-person.

Symptoms

Biphasic illness: 4–28 days after a tick bite, an initial flu-like phase with fever, headache, and muscle pain lasting up to a week. Most patients recover here. About 1 in 3 progress after a symptom-free interval to neurological disease — meningitis, encephalitis, or myelitis. Long-term neurological sequelae are common after the CNS phase.

Treatment

No specific antiviral treatment. Supportive care for the meningoencephalitic phase: hospitalisation, hydration, analgesia, anticonvulsants if seizures, ICU support for severe cases. Recovery from neurological disease is often slow and incomplete.

Endemic regions

Endemic across central, eastern, and northern Europe — including most of Switzerland (excluding cantons of Genève and Ticino), Austria, Germany, Czech Republic, Slovakia, Hungary, Slovenia, Poland, the Baltic states, parts of Scandinavia, Russia, and into northern Asia. The Far Eastern subtype (Russia, parts of China and Japan) is more severe than the European subtype.

Prevention & prophylaxis

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Standard schedule (FSME-Immun / Encepur)

3 intramuscular doses on days 0, 1–3 months, and 5–12 months. Long-term protection: booster every 10 years for all ages (Swiss BAG simplified the schedule in 2022 — previously every 3 years over age 60). Both FSME-Immun and Encepur are inactivated whole-virus vaccines and clinically equivalent. Approved from age 1 (paediatric formulations available).

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Accelerated schedule (last-minute travel)

When the standard 3-dose schedule isn't feasible: Encepur 0, 7, 21 days (officially licensed accelerated schedule), or FSME-Immun 0, 14 days. Both provide protection within 14 days of dose 2. A booster at 12–18 months consolidates long-term immunity. Useful for unvaccinated patients with imminent travel to a high-risk area in tick season.

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Tick-bite avoidance

Wear long trousers tucked into socks and closed shoes when walking in forest, grassland, or scrub. Apply DEET 20–30% or Icaridin 20% to exposed skin and shoes. Permethrin-treated clothing is highly effective. Stick to marked paths. Perform a full body tick check (including scalp, armpits, groin, behind knees) within 2 hours of returning indoors and again before bed.

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Tick removal — what to do

Remove the tick as quickly as possible: grasp it close to the skin with fine-tipped tweezers (not fingers) and pull straight upwards with steady, even pressure — no twisting, no oils, no lighters. Disinfect the bite site afterwards. Note the date and check the area for the next 6 weeks. Seek medical attention if you develop fever, headache, or expanding redness around the bite. Post-exposure TBE vaccination is NOT effective and not recommended.

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⚠ Symptoms after a tick bite

TBE is biphasic: a flu-like illness (fever, headache, myalgia) appears 4–28 days after the bite and lasts 3–7 days, followed by a symptom-free interval. About 20–30% of symptomatic patients then progress to neurological disease (meningitis, encephalitis, myelitis) with stiff neck, severe headache, confusion, or focal weakness. Permanent neurological sequelae occur in 30–60% of CNS cases. Seek urgent medical care for any biphasic febrile illness after a tick bite, especially with neurological symptoms.