Tick-borne Encephalitis (FSME) is becoming more prevalent than ever thanks to climate change and year-round tick activity, according to experts at the University of Hohenheim. The rising concern stems from findings showing FSME-positive ticks are now found even in areas not officially classified as high-risk by health authorities.
Since 2017, the number of FSME cases reported has steadily increased, with the Robert Koch Institute (RKI) documenting 686 cases last year—the second highest number on record after 2020's 718 cases. "This troubling rise is observed not just in traditional hotspots like Bavaria and Baden-Württemberg, but also in regions previously regarded as safe," Professor Ute Mackenstedt, head of Parasitology at the University of Hohenheim, stated during a recent press conference.
The first cases of 2025 have already emerged, with reports indicating infections traced back to the warmer months of winter. "The disease has incubation period of about three weeks, indicating these infections must have occurred during the winter when ticks are typically inactive," noted Professor Gerhard Dobler, director of the National Consiliary Laboratory for FSME at the Bundeswehr Institute of Microbiology.
Contrary to the old belief, ticks can remain active all year round if temperatures exceed five degrees Celsius, thanks to milder winters exacerbated by climate change. "Ticks have adapted remarkably—some can survive temperatures as low as minus seven degrees for several days," Mackenstedt said.
Authorities warn the public against misinterpreting the RKI risk map, which often indicates specific regions as risk-free. This map could suggest false security, as infections have been reported even outside designated risk areas. "It’s important to recognize the inherent risk of FSME exists countrywide," Dobler emphasized. "We need to think about all of Germany as effectively being at risk for FSME, not just the designated areas. Those areas need to be understood as high-risk zones moving forward, rather than simply risk zones.
Mackenstedt added to this distressing narrative, noting, "We're seeing new FSME strains proliferate from Eastern European regions westward; these adaptations mean the tick population could be changing significantly." Reports of new FSME strains arriving from Poland and more broadly across Europe have raised alarms and highlight the necessity for preventative measures.
While the infection hazard increases, so does the urgency for vaccinations. Reports indicate only about 19% of the population are currently vaccinated, leaving the majority vulnerable. "A vaccination is prudent even for individuals across non-designated risk areas, particularly those who enjoy outdoor activities like hiking or foraging," Dobler advised. The vaccination involves three initial doses and should be renewed every five years for overall efficacy. For those over 60 years old, boosters should take place every three years to maintain immunity.
Historically, FSME has shown cyclical trends with diseases recorded every two years rather than three. Though projections for 2025 suggest fewer cases than the troubling heights seen last year, the overall trend still points upward, indicating persistent risks.
Also worth noting, only 1% of FSME-affected individuals had vaccinations, underlining the dire need for improvements. Consequently, the experts recommend individuals educate themselves on nature-related precautions—like wearing long sleeves and employing insect repellent—to reduce tick bites as well.
With the alarming uptick of FSME cases—documented spikes even during warmer winter months—the need for public awareness and prompt vaccinations is more pressing than ever. The potential consequences of infection can be severe, leading to complications such as lasting neurological damage or, in extreme cases, death.
At present, the health community urges all residents, regardless of geographic location, to seek vaccinations and remain vigilant for ticks. Infection thresholds among neighboring countries like Austria, where around 80% of the population is vaccinated yet infections are on the rise, ring alarm bells for Germany and indicate the urgent need for preventive measures.
All signs point toward tick activity proliferations and increased health risks associated with FSME, calling for public education, vigilant health practices, and higher vaccination rollout.