HGE is an uncommon zoonosis, transmitted to humans by ticks (Ixodes ricinus). Heavily exposed persons, such as foresters and forestry workers, are most at risk of infection. HGE usually runs an asymptomatic and self-limiting course. Symptoms include acute pyrexial illness, frequently accompanied by muscle pain, headache, nausea and vomiting. Treatment is with doxycycline/tetracycline or rifampicin. In a study in Hesse of 128 heavily exposed subjects, 19.5% had serum antibodies (IFA test) against HGE versus 4.4% in a control group. This difference is statistically significant. The prevalence of both symptoms and the seropositivity differ significantly between locations. HGE should be considered in the differential diagnosis of fever of unknown origin following tick bite exposure, at least in the North Hesse region.