Unfortunately not. “Until around 2017, every third year was a strong year for ticks, but now it is every second year. So we expect more infections again in 2024,” says Prof. Ute Mackenstedt, head of the parasitology department at the University of Hohenheim. Researchers don’t yet know why there are these ups and downs in infections. Regardless of this, the average number of TBE infections has been rising for years, show statistics from the responsible Robert Koch Institute (RKI).
Ticks are now active all year round. The reason for this is the increasingly mild winters without severe frosts. This means that you can become infected with the dangerous TBE virus all year round. “The RKI registered the first infection this year in February, which means that the tick bite must have taken place in January,” says Mackenstedt. From March/April tick activity increases sharply.
Lyme disease, a bacterial infection, can be contracted virtually anywhere. Things are a little different with TBE, says Mackenstedt: “There are so-called natural foci, places about the size of half a football field, where ticks carry the TBE virus and other places where the virus does not occur.” In these hotspots, the number of TBE-positive ticks varies between 0.5 and three percent; The probability of becoming infected with a bite there is around 1:50. The researchers find out where these natural foci are from infected patients. Anyone who walks the same route with their dog every day can usually easily identify the location of the infection.
The symptoms are initially unspecific: fever and headache can also indicate summer flu or a flu-like infection. “With a TBE infection, severe headaches and a high fever usually occur again two weeks later. Then the viruses are also in the brain or spinal cord,” says the expert.
It is only recently that antibodies that the body produces after a TBE vaccination can be distinguished from those caused by an infection. The ratio of reported cases and those detected by antibodies is approximately 1:7. This means that the vast majority of infections remain undetected.
“Through citizen science projects, we know that the immigrant riparian forest tick in particular is much more widespread and common than previously thought,” says Mackenstedt. Although alluvial forest ticks rarely transmit the TBE virus to humans, they live as larvae and nymphs in the burrows of rodents and pass the virus on to the animals there. Native ticks – the wood ticks – can in turn pick up the virus from such infected rodents and then transmit it to people.
New studies show that horses, dogs and farm animals can also become infected with the TBE virus and become seriously ill.
Ticks like it moist, which is why they are usually more common and active in forests than in the home garden. When dry, they retreat to shady, moist places. Basically, says Mackenstedt: “As soon as you leave the house, you can become infected.”
With climate change, ticks and with them the TBE virus are spreading further and further north. Although most infections are still registered in southern Germany, “basically the whole of Germany is an endemic area,” emphasizes Mackenstedt. In this respect, the distribution maps sometimes create a false sense of security. You can also become infected in areas that are not designated infection areas according to the RKI.
Well-known repellents that can be sprayed on or rubbed in are suitable for repelling ticks, as they mask the body’s own odor that is tempting for the arachnids. However, the best protection against infection with the TBE pathogen is to check for ticks after spending time outdoors. Even better is the mutual inspection by your partner or a family member – even in places that you cannot clearly see yourself. If a tick has already bored into the skin, it can usually be easily removed using a tick card or tweezers. It’s best to then disinfect the bite site with a standard disinfectant spray, because ticks transmit a host of other pathogens in addition to TBE and Lyme disease.
“In Austria, around 80 percent of people are vaccinated against TBE infection, but even with a vaccination rate of 50 percent, the rate of new infections drops significantly,” says Mackenstedt. In Germany, the vaccination rate is only around 17 to 25 percent, depending on the federal state. “Parents often underestimate the risk to their children; they can also become seriously ill with TBE.”
