980 cases of Lyme borreliosis, eleven of tick-borne encephalitis (FSME) by mid-April: As last year, the German ticks are starting the season with a worrying uptick. This is shown by the latest figures from the Robert Koch Institute (RKI).
The parasitic bloodsuckers cause in Germany hundreds of hospital stays and even deaths each year: in 2024, according to the Federal Statistical Office, 25 people in Germany died as a result of a tick bite. 15 of them from the bacterial disease Lyme borreliosis, nine from the viral infection FSME.
With a seroprevalence of 15 to 25 percent, Lyme borreliosis occurs in native ticks far more often than FSME; the virus is carried by only 0.5 to 2 percent of the arachnids. The crucial difference: Lyme borreliosis is a bacterial disease, while FSME is a viral infection. “If you develop FSME and you are not vaccinated, it can have serious consequences and even be fatal,” explains the renowned tick expert Ute Mackenstedt.
Since 1996 she has headed the Department of Parasitology at the University of Hohenheim. While antibiotics can target borreliae, FSME can only be treated for its symptoms. Although anyone living in a high-risk area can receive a FSME vaccination at the expense of health insurance, too few people take advantage of it: “We have too low vaccination rates in many areas. That is simply not enough for protection.”
Climate change is to blame
That there are more and more FSME cases in Germany can be attributed, according to experts, mainly to the effects of climate change. It affects the ticks in several ways. On the one hand, mild winters allow the animals to stay active year-round. “We now have warm winters, without those harsh cold weeks that can take a toll on the ticks,” says Mackenstedt. Another reason is the changed migration routes of birds: “They bring their ticks along with the parasites into Germany.” In this way, ticks introduced from other countries can settle in regions that had not previously been considered FSME risk areas.
Although about 85 percent of known cases currently originate from Bavaria and Baden-Württemberg, FSME now occurs in almost all federal states. “I am not alone in thinking that all of Germany is an FSME risk area,” says Mackenstedt.
By migratory birds, other tick species are now spreading into Germany as well, better adapted to the warmer and drier climate conditions of the future. Among them is Hyalomma, also known as the giant tick. Like every species, it has its own repertoire of pathogens – it can, for example, transmit Crimean-Congo hemorrhagic fever (CCHF). In Germany so far, however, only introduced isolated cases have been recorded.
Despite the rising infection numbers, Mackenstedt emphasizes that one should not panic. “Ticks have been around for millions of years, far longer than we. They have already fed on the dinosaurs,” she explains. An evolutionary success story that cannot be driven away by any means. According to the expert, there is only one thing to do: “We must learn to live with them.”
