Detection of Ehrlichia spp., Candidatus Neoehrlichia sp. (FU98) and Anaplasma phagocytophilum in red foxes (Vulpes vulpes) in Germany.

Vector-borne diseases pose a growing challenge to public health. Effective surveillance, interdisciplinary cooperation in line with the One Health approach, and prevention and control strategies are therefore essential to reduce the risk of future outbreaks and burden of disease in the long term. Identifying and investigating sentinels can help in this regard. In this study, 537 red fox (vulpes) spleen samples from three regions in Germany (Berlin, Brandenburg, Arnsberg administrative region) were tested for Anaplasmataceae and Rickettsia spp. using PCR. Only 3% of the samples (n = 15) tested positive for Anaplasmataceae. Candidatus Neoehrlichia sp. (FU98) was detected most frequently (1.7%; n = 9), followed by Anaplasma phagocytophilum (0.9%, n = 5) and a previously undescribed Ehrlichia sp. genotype (0.4%; n = 2). Rickettsia spp. were not detected. To our knowledge, this is the first finding of Candidatus Neoehrlichia sp. (FU98) in Germany, and our study has also revealed the presence of a previously unknown Ehrlichia species (Ehrlichia sp. ex European carnivore) that is not closely related to E. canis. Anaplasma phagocytophilum was detected in all three regions at low prevalence. Candidatus Neoehrlichia sp. (FU98) in Berlin and Brandenburg but not in Arnsberg. Further studies are necessary to isolate this new agent, as well as to investigate its geographic distribution and host range. Sequences representing an unknown Ehrlichia species were found in one fox sample each in Berlin and Brandenburg. Further investigations are needed regarding its phylogenetic position, vector and host affiliation.