A recently published study shows 84% of ticks collected in urban areas and 77% of those in rural areas in Switzerland contained at least one non-viral pathogen in addition to a number of viruses. Almost every tick has the potential to make you sick, said Cornel Fraefel, a virologist from the University of Zurich who was involved in the study.
Researchers collected and tested a total of 10,286 ticks from rural and urban areas in ten Swiss cantons in 2021 and 2022.
The most common bacteria found were from the Rickettsia group. These pathogens can cause a whole range of diseases that can cause fever, chills and headaches and were found in 70.8% of the ticks.
Borrelia, which is responsible for Lyme disease, was found in many ticks. In urban areas, 8.2% contained the disease and in rural areas 1.9% did.
The Alongshan virus (ALSV), which was first detected in Swiss ticks a couple of years ago was detected in almost twice as many ticks (7.6%) as the well-known tick-borne encephalitis virus (4.2%).
Ticks play an important role in transmitting many different zoonotic pathogens that pose a significant threat to human and animal health. In Switzerland and abroad, the number of tick-borne diseases, in particular tick-borne encephalitis (TBE), has been increasing over the last few years.
Ticks and mosquitos are the primary vectors for transmission of pathogens to humans and animals. Tick-borne infectious diseases have increased worldwide in the recent decades, and ongoing climate change, human activity, mobility, bird migration and expanding tick habitats, will further increase risk areas, said the report. The life span of ticks can last between two and six years, much longer than other vectors. Ticks can also survive harsh conditions through the ability to diapause. Diapause is a delay in development in response to regular and recurring periods of adverse environmental conditions. In addition, to pass each of three developmental stages ticks require a blood meal on a different host, thereby facilitating both the acquisition and transmission of infectious agents. Ticks have a very broad range of hosts and so can exchange pathogens with other tick species by co-feeding on a common host.
Avoiding contact with ticks and carefully removing any that are found are the best ways to prevent infection.
Research report (in English)