Swiss ticks more dangerous than previously assumed, UZH study reveals

Swiss ticks more dangerous than previously assumed, UZH study reveals

An-ever present part of wildlife in Switzerland, you’d be hard-pressed to find someone in the alpine nation who isn’t aware of tick season. Now, a new study from the University of Zurich has found that the little bloodsuckers are far more likely to carry disease than previously thought, with the vast majority of ticks analysed carrying some form of illness.

Majority of ticks in Switzerland carry disease

In the analysis of over 10.000 ticks from across 10 cantons in Switzerland, the university found that 77,2 percent of the critters tested positive for at least one non-viral pathogen like bacteria. Among ticks collected in urban areas, this rate rose to 83,9 percent.

Speaking to SRF, University of Zurich virologist Cornel Fraefel said that “almost every tick can potentially make you sick…We were surprised by how many ticks we found bacteria in.” “We found several pathogens at the same time in many ticks”, he added.

4,2 percent of Swiss ticks carry TBE, study finds

Ticks are commonly found in all parts of Switzerland, even as high as the mountains, though they do prefer areas below 2.000 metres above sea level. What’s more, Ticino and Geneva are the only cantons that are not considered TBE (tick-borne encephalitis) risk areas. 

In the study, 4,2 percent of Swiss ticks were found to have the TBE virus, which can cause symptoms like fever, headache and nausea. In limited cases, bites from ticks with the TBE pathogen can also lead to the development of brain inflammation and neurological symptoms like meningitis, encephalitis or meningoencephalitis.

Newly discovered ALSV virus found in ticks

The most common bacteria found in Swiss ticks was from the Rickettsia group, a bacteria that can cause symptoms such as fever, chills and headaches in humans. Borellia, the vector for Lyme disease, was spotted in 8,2 percent of ticks in urban areas and 1,9 percent of ticks in rural regions. Another notable addition was the detection of the so-called Alongshan virus (ALSV) in 7,6 percent of specimens analysed. 

The disease, first detected in Inner Mongolia, China in 2019, is said to cause similar symptoms to TBE with the exception of neurological symptoms - however, it needs to be noted that it is yet to be concluded whether ALSV is solely responsible for the symptoms. “The discovery of ALSV is so new that it is not yet possible to say whether it is relevant to public health in Switzerland,” Fraefel concluded.

Ticks in Switzerland 

Ticks are most active in the spring and summer months, preferring warm and wet weather. They tend to lie in wait for passing humans and animals in long grass, meadows, forests and verges. While ticks shouldn’t dissuade you from embracing all the Swiss outdoors has to offer, it's important to still keep them in mind.

The best protection against tick bites is to prevent them entirely. Wearing long-sleeved shirts and trousers when walking in tall grass and wearing insect repellent can prevent tick bites. When you get back home, always check to see if any ticks have bitten you, your pets or your family.

What to do if bitten by a tick in Switzerland

If you do find a tick, don’t panic as so long as the critter is removed carefully there should be no problem. The best thing to do is to use tweezers to grasp the tick as close to the skin’s surface as possible and apply steady upward pressure until the tick is removed, then wash the bite area thoroughly and dispose of the tick without crushing it.

Never try to crush a tick with your fingers or scratch the tick off, as this may lead to excess parts of the tick being stuck in the skin. If you start to develop a rash or fever within three weeks of removing the tick, see your doctor.

For more information about the study, please visit the official website.

Jan de Boer


Jan de Boer

Jan studied in York and Sheffield in the UK, obtaining a master's in broadcast journalism and a bachelor's in history. He has worked as a radio DJ, TV presenter, and...

Read more



Leave a comment