A case of equine granulocytic ehrlichiosis provides molecular evidence for the presence of pathogenic Anaplasma phagocytophilum (HGE agent) in Germany

Based on seroprevalence studies and tick infection rates, tick-borne human granulocytic ehrlichiosis (HGE) is thought to occur in Germany, but to date no clinical case has been detected. Reported here are the first ehrlichial sequences derived from a German horse that fell ill with granulocytic ehrlichiosis. The analysis of three different genes (16S rRNA gene, groESL, and ankA) revealed up to 100% identity with ehrlichial sequences derived from patients with HGE in other countries or from infected ticks in Germany. Thus, the current lack of clinical cases of HGE in Germany is unlikely to result from the absence of pathogenic granulocytic ehrlichiae strains in German ticks.