As soon as the temperatures rise, the tick season begins – sometimes quite early in the year. “We already had phases this year where ticks were already active in places,” says Gerhard Dobler from the Bundeswehr Institute for Microbiology in Munich. In general, there is a shift forward, explains the expert. “This is also reflected in the fact that TBE cases occur earlier.”
The Bavarian State Office for Health and Food Safety (LGL) in Erlangen has already registered three cases of tick-borne meningitis (TBE), which is mostly transmitted by ticks. Last year there were a total of 260. According to the authorities, there has been a significant increase in TBE numbers in Bavaria in recent years. It was only at the beginning of the month that the Robert Koch Institute declared the district of Fürstenfeldbruck and the urban district of Munich as risk areas – this means that 94 of the 96 Bavarian districts and independent cities are now considered such.
Not only in southern Germany, but also in the Czech Republic, Austria and Switzerland, despite vaccination, there has been an increase in TBE numbers since 2015, says Dobler. “We believe that climate change plays a role in this. We just don’t know how yet.” One hypothesis is that the virus is more active because of the warmer winters because the ticks are also active earlier in the year.
Dobler and his team are currently collecting ticks in the risk areas to examine them for the virus. As early as February, he discovered ticks in a Munich park, says Dobler.
TBE cases are increasing in the Alps; there used to be none at all
In his opinion, the climate crisis could also be responsible for the increase in TBE cases at higher altitudes. Accordingly, they occur more frequently along the northern ridge of the Alps and north of the Ore Mountains. There used to be no cases at all there. The LGL expert Volker Fingerle considers it likely that the most common tick species in this country, the common wood tick, could spread further in northern Europe. Individual studies have already provided evidence that it occurs more frequently at higher altitudes. “But that requires long-term studies.”
According to him, there are more than 20 different tick species in Germany. There are around 900 worldwide. With global warming, new species could also gain a foothold in this country, says Fingerle. An example is the so-called Hyalomma giant tick, which is native to the arid and semi-arid regions of Africa, Asia and southern Europe. Migratory birds bring them to Germany. Ticks usually die in winter because they can’t stand the cold, says Fingerle. “We will certainly face that the climate will be such that it will survive the winter or that it will adapt.”
The Standing Vaccination Commission (Stiko) recommends a TBE vaccination for people who live, work or stay there for other reasons in TBE risk areas and are therefore at risk of tick bites. A TBE infection is initially accompanied by flu-like symptoms. Some of those affected later develop inflammation of the meninges, the brain and the spinal cord. Some patients have long-term effects, such as paralysis. The disease can also be fatal. The first symptom of Lyme disease is often increasing reddening around the puncture site, later nerves, joints and the heart can be affected by the bacteria.