Scientists worry: Twice as many ticks as last year – Health & Nutrition

More than twice as many ticks as last year are expected to crouch in meadows and meadows this summer in Grsern, waiting for visiting guests. Specifically, 443 leeches per standard area of ​​100 square meters. This figure was prophesized by Gerhard Dobler and his team at the Institute of Microbiology of the German Armed Forces, a partner institute of the German Infection Research Center (see interview).

Initial investigations show that the new predictive model works. Now the goal is: more details. The German tick community collects ticks every month in 100 different sites in Germany – it's currently the largest field study of its kind in the world and the arachnids found are also being examined for different pathogens.

How to control the routes of infection? TBE virus is the goal of researchers. It can cause early meningoencephalitis, a meningitis very dangerous for humans. Until now, they have not yet fully understood the extremely complex ecological mechanism that represents the pathway of infection by ticks, mice and even ticks – in simple terms -. However, this would be the prerequisite to be able to control the cycle with natural factors and thus suppress the outbreaks of infection. "What we do know is that the virus is very stable, unlike the influenza virus, for example, the mutation rate is only 0.05%," says microbiologist Dobler of Munich. infect with a pathogen. The best known are the TBE virus and Lyme borrelia. Both pathogens are transmitted by the common woodbuck of Schildzecke, which is the most common in our climates. According to experts, every third to fourth tick is infected with Lyme borrelia. It is estimated that between 60,000 and 200,000 people in Germany suffer each year. The numbers vary so much because the disease is not notifiable in all federal states.

"We badume that many more pathogens are transmitted by ticks than was previously described," says Peter Hagedorn of the Robert Koch Institute. (RKI). Animals are excellent transmitters that can carry a pathogen from one host to another. And they have plenty of time to transfer the germs: the larvae suck their host for five days, the nymphs seven and the adult animals for twelve days.

There are about 20 tick-borne diseases in the world, says Hagedorn. These include, for example, anaplasmosis, an infectious disease in which the bacterium infects white blood cells. "It is very common in North America, where anaplasmosis is one of the emergency diseases, so the medical emergency," says the graduate biologist. In Germany, however, no case of anaplasmosis has been described so far, although 5% of ticks carry the pathogen.

Babesia infection resembles the evolution of malaria. Pathogens attack and alter red blood cells, which can lead to serious, sometimes fatal, disease, especially in immunocompromised individuals. Mediterranean spotted fever or purple spot fever can affect holidaymakers in Mediterranean countries. Ticks here can transmit what are called rickettsiae.

Wiederkuer did not support pathogens

But there is no reason to panic in a record summer. The fact that a high population of ticks actually causes more illness is pure speculation. "There is no clear ordinary study that proves this," says Dania Richter, who is doing research at the Technical University of Braunschweig, particularly with Lyme disease. There are seven different types of these Borrelia, five of which can make us sick.

It is interesting that Wiederkuer does not support these pathogens. "So, if a tick carrying Lyme borrelia sucks a cow or deer, the pathogen will be eliminated – very simply said – and that tick will not be able to infect humans with it in the next step," says Richter. What is the risk of catching a tick, including a Borrelia genus, Dania Richter has also studied with colleagues. "The decisive factor is the form of land use," she says. For example, four percent of ticks were infected on a surveyed pasture, but about 17 percent on a directly adjacent fallow. During a two-day walk across the pasture, scientists encountered an infected tick on average; During the same period, 56 animals carrying Lyme Borrelia, living with diseases, lived on a fallow.