Hansen et al.
Cervids and racoon dogs as wildlife sentinels for the geographical distribution of tick-borne encephalitis virus and Francisella tularensis in Denmark. Ticks Tick Borne Dis. 2025, 16:102466. doi:1016/j.ttbdis.2025.102466
In Denmark, TBE endemic areas have been known on the island of Bornholm since the 1950s. Since 2008, multiple TBE cases have been reported from northern Zealand (the largest Danish island), but only a few cases have been observed outside of these two TBE endemic regions. A seroepidemiological study has been carried out to examine the distribution of TBE virus and Francisella tularensis using cervids and racoon dogs as sentinel species.
A total of 717 cervids samples (roe deer, red deer, fallow deer, and sika deer) were collected and analyzed from three winter seasons. In addition, 67 blood samples from racoon dogs were analyzed.
For TBE, a total of 26/423 (4%) cervids from eight sites and 1/64 racoon dogs were ELISA positive. 24 of the sera were tested in a neutralization assay. 5/24 samples from cervids from the island of Zealand and one racoon sample from the peninsula of Jutland were NT positive.
The results from this study confirm a continuous circulation of TBE virus among Danish wildlife and highlight the potential of humans to acquire TBE virus infections at least on the island of Bornholm, the island of Zealand and Jutland.