Rickettsia slovaca in Dermacentor marginatus ticks, Germany

Rickettsia slovaca in Dermacentor marginatus ticks, GermanyTo the Editor: Dermacentor spp.ticks are found in many countries in Europe, and are vectors for several pathogens, including Francisella tularensis, Coxiella burnetii, Rickettsia spp., and Babesia canis (1,2).Because Dermacentor marginatus ticks require warm dry habitats, these ticks are found in only a few areas in southern Germany, mainly in the Rhine and Main valleys (3).However, these ticks may spread northwards because of increasing temperatures.In contrast, D. reticulatus ticks are present throughout Germany.Fourteen Rickettsia spp.are currently identifi ed as human pathogens.The severity of human diseases differs among these species, ranging from mild to lethal illness (4).On the basis of serologic and genotypical characteristics, rickettsiae are divided into typhus and spotted fever groups.Within each group, antigenic differences are small, resulting in cross-reactivity that complicates differentiation of Rickettsia spp.by serologic methods.Therefore, PCR of eschar biopsy samples is a useful tool for diagnosis of rickettsial diseases (5).Little information exists regarding the prevalence of Rickettsia spp. in D. marginatus and D. reticulatus ticks in Germany.R. raoultii was recently detected in 23% of D. reticulatus ticks (6).In 1977, Rehacek et al. identifi ed R. slovaca in 12% of Dermacentor spp.ticks from southern Baden-Wuerttemberg (7).Since then, this pathogen has not been detected in Germany.R. slovaca, a member of the spotted fever group, causes tick-borne lymphadenopathy, a relatively mild rickettsiosis (8).We report detection of R. slovaca in 5 of 666 Dermacentor spp.ticks from southern Germany.Moreover, we identifi ed a case of