Nina Król

This atlas provides updated maps based on georeferenced tick locations of 22 species endemic in Germany, three regularly imported tick species and one species that was previously frequently imported into Germany. Thus, the current version of the atlas of ticks in Germany contains distribution maps for a total of 26 tick species with the following numbers of newly georeferenced tick locations: 1 Argas reflexus , 10 Carios vespertilionis , 3 Dermacentor marginatus , 53 Dermacentor reticulatus , 10 Haemaphysalis concinna , 7 Haemaphysalis punctata , 2 Hyalomma aegyptium , 111 Hyalomma marginatum , 39 Hyalomma rufipes , 2 Ixodes arboricola , 2 Ixodes crenulatus (syn. Ixodes canisuga ), 27 Ixodes frontalis , 43 Ixodes hexagonus , 6 Ixodes lividus , 271 Ixodes ricinus , 1 Ixodes rugicollis , 5 Ixodes trianguliceps , 1 Ixodes uriae , 2 Ixodes ventalloi , 1 Ornithodoros maritimus , and 32 Rhipicephalus sanguineus sensu lato. Ixodes inopinatus has been removed from the previously included species list because more recent studies have shown that these were misidentifications. The rabbit tick I. ventalloi , the argasid seabird tick O. maritimus and the formerly frequently imported tortoise tick Hy. aegyptium , however, have been included in the current atlas of ticks in Germany. In total, the digital dataset available for Germany is updated by 629 new tick locations. These records increase the number of tick species mapped in the federal state Saxony by six, those in Hamburg by five, those in Brandenburg by four, those in Schleswig-Holstein by three, those in Baden-Wuerttemberg, Bavaria and Thuringia by two each, and those in Bremen, Northrhine-Westphalia, Rhineland Palatinate and Saarland by one each. Of the 26 tick species ever detected in Germany, 21 were observed in the period 2001–present. Thus, the second data update of the atlas of ticks in Germany provides the most comprehensive digital dataset to date on the distribution of tick species in Germany.

(1) Background: Tick-borne encephalitis (TBE) is the most important tick-borne viral disease in Eurasia, although effective vaccines are available. Caused by the tick-borne encephalitis virus (TBEV, syn. Orthoflavivirus encephalitidis), in Europe, it is transmitted by ticks like Ixodes ricinus and Dermacentor reticulatus. TBEV circulates in natural foci, making it endemic to specific regions, such as southern Germany and northeastern Poland. Our study aimed to identify new TBEV natural foci and genetically characterize strains in ticks in previously nonendemic areas in Eastern Germany and Western Poland. (2) Methods: Ticks were collected from vegetation in areas reported by TBE patients. After identification, ticks were tested for TBEV in pools of a maximum of 10 specimens using real-time RT-PCR. From the positive TBEV samples, E genes were sequenced. (3) Results: Among 8400 ticks from 19 sites, I. ricinus (n = 4784; 56.9%) was predominant, followed by D. reticulatus (n = 3506; 41.7%), Haemaphysalis concinna (n = 108; 1.3%), and I. frontalis (n = 2; <0.1%). TBEV was detected in 19 pools originating in six sites. The phylogenetic analyses revealed that TBEV strains from Germany and Poland clustered with other German strains, as well as those from Finland and Estonia. (4) Conclusions: Although there are still only a few cases are reported from these areas, people spending much time outdoors should consider TBE vaccination.

Rickettsiae of the spotted fever group (SFG) are zoonotic tick-borne pathogens. Small mammals are important hosts for the immature life stages of two of the most common tick species in Europe, Ixodes ricinus and Dermacentor reticulatus. These hosts and vectors can be found in diverse habitats with different vegetation types like grasslands and forests. To investigate the influence of environmental and individual factors on Rickettsia prevalence, this study aimed to analyse the prevalence of SFG rickettsiae in ticks and small mammals in different small-scale habitats in central Germany for the first time. Small mammals of ten species and ticks of two species were collected from grasslands and forests in the Hainich-Dün region, central Germany. After species identification, DNA samples from 1098 ticks and ear snips of 1167 small mammals were screened for Rickettsia DNA by qPCR targeting the gltA gene. Positive samples were retested by conventional PCR targeting the ompB gene and sequencing. Rickettsia DNA was detected in eight out of ten small mammal species. Small mammal hosts from forests (14.0%) were significantly more often infected than those from grasslands (4.4%) (p < 0.001). The highest prevalence was found in the mostly forest-inhabiting genus Apodemus (14.8%) and the lowest in Microtus (6.6%), which inhabits grasslands. The prevalence was higher in D. reticulatus (46.3%) than in the I. ricinus complex (8.6%). Adult ticks were more often infected than nymphs (p = 0.0199). All sequenced rickettsiae in I. ricinus complex ticks were R. helvetica, and the ones in D. reticulatus were R. raoultii. Unlike adults, questing nymphs have had only one blood meal, which explains the higher prevalence in I. ricinus adults. Interestingly, habitat type did influence infection probability in small mammals, but did not in ticks. A possible explanation may be the high prevalence in Apodemus flavicollis and A. sylvaticus which were more abundant in the forest.