Tick-borne encephalitis trends in Northern Europe

Tick-borne encephalitis (TBE) cases have shown significant activity in Northern Europe during 2026.

In Finland, cases increased sharply during the summer, with approximately 338 to 340 identified cases compared to 240 in the previous year. Regional increases were noted in Uusimaa, Northern Ostrobothnia, Northern Savonia, and Southwest Finland. Medical professionals observed that many diagnosed individuals had not received the TBE vaccine or had an incomplete vaccination series.

In Lithuania, health officials reported 380 cases of TBE between January and August 2026, including four deaths. While this total is slightly lower than the 438 cases and three deaths recorded during the same period in 2025, officials warned of a second wave of tick activity as autumn approaches. Additionally, Lithuania recorded 8,164 cases of Lyme disease during the first eight months of the year.

As autumn progresses, health authorities in Lithuania and Latvia have issued warnings regarding rising risks. The Lithuanian National Public Health Center (NVSC) noted that ticks enter a new developmental stage when temperatures reach approximately 5–7 degrees Celsius, increasing infection risks for individuals engaged in outdoor activities like berry gathering or mushroom picking.

In Latvia, the Centre for Disease Prevention and Control (SPKC) also reported a high risk of tick-borne diseases. Historical data from Latvia shows an upward trend, with 186 TBE cases recorded in 2025 and 539 Lyme disease infections, both representing increases over previous years. In certain Latvian regions, encephalitis vaccination is state-funded for children.