New tick species discovered in Germany: does it transmit viruses?
DZIF scientists in Munich investigate the spread of tick-borne encephalitis (TBE) in Germany and encounter a new potential transmitter of this dreaded disease: a tick species called Ixodes inopinatus.
Initial associations with the term “emerging infections” usually involve diseases like Ebola and MERS or chikungunya and Zika fever. However, dangerous zoonoses, i.e. viral infections that can spread rapidly and are transmitted from animals to humans, also exist in Germany. An example is early tick-borne encephalitis (TBE), a viral infection that often manifests as meningitis which can be fatal. This infection has been emerging in new regions in Germany and was also detected in the Netherlands for the first time in 2016.
For several years, a small research group led by Dr Gerhard Dobler in Munich at the Bundeswehr Institute of Microbiology has been researching the spread of TBE viruses in Germany and Central Europe. The aim of the project, which is also funded by the DZIF, is to better understand mechanisms of spread and consequently optimise surveillance and control measures in collaboration with public health authorities.
Do ticks transmit the virus?
For years, the Munich researchers have been focusing on birds. Results from molecular biological investigations of TBE viruses from different regions in Europe show that the virus spreads along known bird migration routes. However, up to now it has been unclear as to how the virus spreads: through infected ticks or viral infections that persist for longer periods in the birds themselves. In a sub-project, a team is collecting ticks from birds and at bird pit stops in order to identify different types of ticks and potentially detect newly imported tick species as well as TBE virus strains.
A new tick species is under suspicion
Investigations of known TBE regions in southern Germany showed that stable populations of Ixodes inopinatus, a species previously only found in the Mediterranean region, exist there too. This tick species, previously unknown in Germany, gives rise to many questions: can Ixodes inopinatus transmit pathogens that already exist in Germany (including TBE)? Is the import and spread of this tick species responsible for the spread of TBE in Central Europe? Could they potentially be responsible for new, previously unknown pathogens spreading in Germany? The Munich researchers have investigated these questions and others, and now collaborate closely with Bavarian and Baden-Württemberg public health authorities as well as with other university partners to find out more about the (veterinary) medical implications of this tick species.
However, besides this new species, other tick species which have only been found in Germany occasionally or many years ago and have not been described again since have also been discovered. “Tick fauna is much more diverse than previously assumed,” explains Dobler, “particularly in birds when these are specifically investigated. The impact of their spread across the continents has only been sparingly researched and could be more relevant to emerging tick-borne diseases than has previously been assumed,” the scientist emphasizes.
Oldest tick in the world discovered
The Munich group’s expertise, meanwhile globally recognised, also had a further sensational scientific “by product”: a description of the oldest tick in the world, found in amber that is over 100 million years old. The identification of this tick species has led to a completely new understanding of tick evolution.
