Prevalence of antibodies to Borrelia burgdorferi in Danish deer.

To estimate the prevalence of antibodies to Borrelia burgdorferi in the most common species of Danish deer, blood samples were collected from roe deer (Capreolus capreolus), fallow deer (Dama dama), and red deer (Cervus elaphus). A total of 156 blood samples were collected primarily from hunts in three areas of Denmark from November 1990 to December 1991. Presence of deer IgG antibodies to the Borrelia burgdorferi strain DK ECM 1 were shown by an indirect immunofluorescence assay at serum titre 1:64. Antibodies to spirochaetes were detected in 52% of roe deer, 38% of fallow deer, and 27% of red deer. There were significant differences between the number of seropositive animals in the three areas of Denmark examined, but no differences could be shown for age, sex or season. The high antibody prevalence indicates that deer are exposed to tick-borne Borrelia burgdorferi throughout Denmark.