No tick-borne encephalitis virus and no Borrelia burgdorferi sensu lato detected in Dermacentor reticulatus ticks from Luxembourg

• OH4Surveillance
• Clinical and Applied Virology
• Department of Infection and Immunity

Tick-borne diseases are on the rise due to the geographical expansion of their tick vectors and higher frequencies of infected ticks. Increased awareness of infection and improved diagnostic methods facilitate their detection. Tick-borne encephalitis (TBE) and Lyme disease (LD) are the most common and most widely distributed tick-borne infections in Europe. Several cases of LD are being reported in Luxembourg each year. To date, no autochthonous TBE case has been detected in Luxembourg; however, human cases and seropositive animals are being reported in neighboring countries. 

Therefore, surveillance of tick-borne encephalitis virus (TBEV) and Borrelia burgdorferi sensu lato causing LD has been implemented in the country in the context of the EU co-funded OneHealth4Surveillance project (2024-2026).

In 2024, the Clinical and Applied Virology team of LIH has screened 510 Dermacentor reticulatus ticks, kindly provided by the Luxembourg National Museum of Natural History in the context of a collaboration, for TBEV and B. burgdorferi s.l. The pathogens were not detected in any of the ticks, probably because this tick species is not a primary vector for these pathogens. Moreover, pathogen prevalence, especially for viruses like TBEV, can be very low and spatially variable, making detection challenging without extensive sampling. Continued screening is therefore necessary and should be extended to other tick species that play a more significant role in pathogen transmission to better understand local epidemiology. In spring 2025, nationwide tick collections were started and first results of the screening are expected towards the end of the year.

Disclaimer
This activity is supported by co-funding from the European Union’s EU4Health programme under Grant Agreement Nr 101132473 OH4Surveillance.
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