Dermacentor reticulatus and Babesia canis in Bavaria (Germany)—A Georeferenced Field Study with Digital Habitat Characterization

The hard tick Dermacentor reticulatus transmits Babesia canis, the causative agent of canine babesiosis. Both the occurrence and local distribution of D. reticulatus as well as infection rates of questing ticks with B. canis are thus far poorly known in Bavaria, Germany. The objectives of this study were to conduct (1) a georeferenced field study on the occurrence of D. reticulatus with digital habitat characterization and (2) a PCR analysis of D. reticulatus collected in Bavaria for infection with B. canis. Dermacentor reticulatus were collected by flagging at 60 sites specifically selected according to habitat conditions and screened individually for Babesia DNA. A digital habitat characterization for D. reticulatus was performed according to results of the field analysis including the parameters land use, proximity to water, “potential natural vegetation”, red deer corridors and climate data. Altogether, 339 D. reticulatus ticks (214 females and 125 males) were collected between 2010 and 2013 at 12 out of 60 sampling sites. All 12 sites were characterized by high humidity with marshy areas. Babesia canis DNA was detected in 1 out of 301 (0.3%) questing D. reticulatus in Bavaria. The digital habitat characterization revealed 15 forest areas in Bavaria with similar ecological characteristics as the sites positive for D. reticulatus.