The number of ticks is currently increasing rapidly

A real year of ticks is in progress

The last winter was rather mild, the spring too hot, and summer is also on the hottest side. As a result, ticks and other pests multiply rapidly. For this reason, experts suggest the alarm: 2018 should be a real tick year. "There will be more cases of meningitis or Lyme disease," warns, for example, the German Infection Research Center (DZIF).

This summer, there will be a particularly high number of ticks and therefore a higher risk of contracting meningitis or Lyme disease – because these diseases are transmitted by ticks. DZIF scientists in Munich predict a "tick year". They have co-developed a model that will allow them to predict the density of ticks already in winter for next summer.

A summer walk through the forest or even through the garden can have unpleasant consequences. Because on bushes, shrubs and grasses are ticks, usually the common male, Ixodes ricinus, who patiently waits for a vertebrate, a human for example, to come and take it with him. If it's found its place on the skin, then it stings and sucks the blood until it almost bursts. However, with his saliva, he returns some of the blood and, in some cases, an unpleasant cargo.

For example, the common male is the main transmitter of tick-borne encephalitis (TBE), a viral meningitis that can be fatal. Lyme disease is transmitted by this tick species. Although there is no cure but a preventive vaccination for FSMEs, there is no vaccine against Lyme disease, but a treatment option with antibiotics. In all cases, ticks should be considered, especially in TBE risk areas. There, more ticks are infected with viruses than anywhere else. In what regions of Germany it is, one learns on the website of the Robert Koch Institute: Map FSME.

"This year, the risk is particularly high," Privatdozent. Gerhard Dobler sure. "We will have the greatest number of ticks in the last ten years." Since 2009, the DZIF researcher and his team at the Institute of Microbiology of the German Armed Forces are studying the spread and activity of the virus TBE in Germany. Over a period of nine years, researchers have documented the number of ticks at a source of infection in southern Germany. For this, they meticulously collected nymphs from the common wood block monthly – a stage of tick development before growing. Less than one millimeter, these juveniles are only recognizable as blackheads and are often overlooked. This makes them particularly dangerous because even at this stage of development, they can transmit diseases. Scientists have been able to show that the source of infection selected in southern Germany has a character of style. "If we have a lot of ticks here, then we have these high figures elsewhere in southern Germany," says Dobler

Predictive Model Complex Confirmed

"Using tic data from our range of models and specific environmental parameters, at the University of Veterinary Medicine in Vienna, we develop a model that prepares us for ticks in the summer, "says Dobler. On the one hand, the number of beechnuts two years before the current summer, as well as the average annual temperature and winter temperature of the previous year are pouring into the model of Munich and Vienna. The more hay there is two years before the summer in question, the more game and rodents have food and serve as carriers of ticks, which also appear more.

Dobler and his colleagues were able to use the connections in their complex model and confirm it. By the summer of 2017, they had predicted 187 ticks per standardized zone and found 180 ticks. Almost a landing point. By 2018, the largest number of ticks ever found was predicted with 443 ticks, and Dobler now knows that this prediction will also be respected. "We have the highest number of ticks collected since the beginning of the study – good for ticks, bad for us."

Preventing the Risk of Infection

More ticks always mean an increased risk of contracting. Lyme disease can be transmitted by ticks all over Germany and can be found in about one in four ticks, regardless of region. Here, only vigilance for forest walks and open-air stays helps to avoid it. The faster the tick is removed, the lower the risk of Lyme disease. To prevent the danger of meningitis, one can and must be vaccinated, so the scientists call. Especially in southern Germany, where the density of ticks infected with the virus is higher.

Tick dressed in silk

The collection and mapping of ticks is one thing. But Munich's team still finds finds that go back far in history. One of those exciting discoveries of late should be at least mentioned here: The discovery of a tick that caught in a spider's web and was covered by spider silk to death . This drama occurred about 100 million years ago. And has been included and recorded for posterity in amber. (pm, sb)