Ticks in Switzerland More Dangerous Than Previously Thought


Researchers at the University of Zurich have found viruses or bacteria in almost all the ticks they have examined, including the Alongshan virus, which was discovered a few years ago.

“Almost every tick can potentially make you ill,” virologist Cornel Fraefel from the University of Zurich, who took part in the study, told the Swiss News Agency Keystone-ATS on Monday. “In many ticks, we found several pathogens at the same time.”

The Alongshan virus (ALSV) was detected in almost twice as many ticks (7.6%) as the meningoencephalitis virus (4.2%). Around 77% of ticks also tested positive for at least one non-viral pathogen. Of the ticks collected in urban areas, 83.9% contained at least one non-viral pathogen.

The dangerousness of ALSV has not yet been clearly established. “The discovery of ALSV is so recent that we can’t yet say whether it is relevant to public health in Switzerland,” Fraefel said. According to a Chinese study, the symptoms resemble those of meningoencephalitis.

Rickettsiae and borrelia

Bacteria from the rickettsia group, which can trigger a whole series of diseases known as rickettsioses, were found most often in the ticks examined by the Zurich researchers. These include anaplasmosis, which can cause fever, chills and headaches.

Borrelia, responsible for Lyme disease, was also detected in many ticks. In urban areas, borrelia was present in 8.2% of ticks examined (1.9% in rural areas).

The University of Zurich researchers extracted RNA and DNA from more than 10,000 ticks and tested them for viruses. The ticks were also tested by PCR for various bacteria. The results have been published in the specialist journal Plos One.

Source : SWI