Reticulatus Ticks Research Articles

Prevalence of tick-borne encephalitis virus (TBEV) RNA in Dermacentor reticulatus ticks from natural and urban environment, Poland.

Tick-borne encephalitis virus (TBEV) (Flaviviridae, Flavivirus) is an arthropod-borne virus, an etiologic agent of tick-borne encephalitis (TBE), a human infection involving the central nervous system. The disease is endemic in a large region in Eurasia, where it is transmitted mainly by Ixodes ricinus and Ixodes persulcatus ticks. It is known that also Dermacentor reticulatus is involved in circulation of TBEV. However, the current knowledge of D. reticulatus importance in TBE epidemiology is still insufficient. A total of 471 adult D. reticulatus ticks were collected by flagging vegetation in the Białowieża Primeval Forest, Biebrza National Park, Masurian Landscape Park (North-Eastern Poland) and in the city of Warsaw in the years 2007–2010. All collected ticks were examined individually for the presence of RNA of TBEV using nested RT-PCR assay. Positive results were noted in all investigated localities with the infection rate ranging from 0.99 to 12.5 % with a total mean of 2.12 %. The difference in the percentage of infective males and females was not statistically significant.

The infection of questing Dermacentor reticulatus ticks with Babesia canis and Anaplasma phagocytophilum in the Chernobyl exclusion zone

Tick occurrence was studied in the Chernobyl exclusion zone (CEZ) during the August–October 2009–2012. Dermacentor reticulatus ticks were collected using the flagging method and then screened for infection with Anaplasma phagocytophilum and Babesia canis by a PCR method incorporating specific primers and sequence analysis. The prevalence of infection with B. canis canis and A. phagocytophilum was found to be 3.41% and 25.36%, respectively. The results present the first evidence of B. canis canis and A. phagocytophilum in questing D. reticulatus ticks from the Chernobyl exclusion zone. They also reveal the presence of tick-borne disease foci in areas with no human activity, and confirm that they can be maintained in areas after a nuclear disaster with radioactive contamination.

Prevalence of Babesia canis, Borrelia burgdorferi sensu lato, and Anaplasma phagocytophilum in hard ticks collected from meadows of Lubelskie Voivodship (eastern Poland)

Abstract The aim of the study was to assess the distribution of Anaplasma phagocytophilum, Borrelia burgdorferi sensu lato, and Babesia canis in adult females and males of Ixodes ricinus and Dermacentor reticulatus ticks, inhabiting meadows near large forest complexes throughout the Lubelskie Voivodship (eastern region of Poland). Ticks were collected using the flagging method. Among 720 ticks collected, 506 were identified as D. reticulatus, and 214 as I. ricinus. DNA of B. canis and B. burgdorferi s.l. was detected in 21.3% and 0.6% of D. reticulatus ticks, respectively. In I. ricinus ticks, DNA specific to B. burgdorferi s.l. and A. phagocytophilum was detected in 5.6% and 10.3%, respectively. Co-infections of B. burgdorferi s.l. and A. phagocytophilum were found in two I. ricinus ticks. These results indicate that the Lublin region is an area at risk of tick-borne diseases of humans and animals, which must be considered in clinical practice.

A Systems Biology Approach to the Characterization of Stress Response in Dermacentor reticulatus Tick Unfed Larvae

Background Dermacentor reticulatus (Fabricius, 1794) is distributed in Europe and Asia where it infests and transmits disease-causing pathogens to humans, pets and other domestic and wild animals. However, despite its role as a vector of emerging or re-emerging diseases, very little information is available on the genome, transcriptome and proteome of D. reticulatus. Tick larvae are the first developmental stage to infest hosts, acquire infection and transmit pathogens that are transovarially transmitted and are exposed to extremely stressing conditions. In this study, we used a systems biology approach to get an insight into the mechanisms active in D. reticulatus unfed larvae, with special emphasis on stress response.Principal FindingsThe results support the use of paired end RNA sequencing and proteomics informed by transcriptomics (PIT) for the analysis of transcriptomics and proteomics data, particularly for organisms such as D. reticulatus with little sequence information available. The results showed that metabolic and cellular processes involved in protein synthesis were the most active in D. reticulatus unfed larvae, suggesting that ticks are very active during this life stage. The stress response was activated in D. reticulatus unfed larvae and a Rickettsia sp. similar to R. raoultii was identified in these ticks.SignificanceThe activation of stress responses in D. reticulatus unfed larvae likely counteracts the negative effect of temperature and other stress conditions such as Rickettsia infection and favors tick adaptation to environmental conditions to increase tick survival. These results show mechanisms that have evolved in D. reticulatus ticks to survive under stress conditions and suggest that these mechanisms are conserved across hard tick species. Targeting some of these proteins by vaccination may increase tick susceptibility to natural stress conditions, which in turn reduce tick survival and reproduction, thus reducing tick populations and vector capacity for tick-borne pathogens.

The risk of vector-borne infections in sled dogs associated with existing and new endemic areas in Poland. Part 2: Occurrence and control of babesiosis in a sled dog kennel during a 13-year-long period

The achievements of sled dogs in competitions depend both on their training and on their health. Vector-borne infections may lead to anemia, affect joints or heart muscles or even cause death. Canine babesiosis is an emerging, quickly spreading tick-borne disease in Central Europe. Over a 13-year period (2000–2012) the occurrence of babesiosis cases was analyzed in one sled dog kennel situated in Kury, a village near Tłuszcz (N 52°24′56.78″, E 21°30′37.55″) in Central Poland. Twenty cases/episodes of babesiosis were noted among the 10–12 dogs living in the kennel. In 2000–2004, no cases of babesiosis were noted; the first two cases were noted in April 2005. Since that time, only one dog remained uninfected; 6 dogs were infected once, 3 dogs demonstrated symptoms of babesiosis twice, one dog was infected three times and one dog had it five times. Babesiosis appeared in Spring and Autumn, despite the application of anti-tick treatment. No fatal cases were recorded, but in one case a splenectomy was performed due to splenomegaly and spleen rupture. Additionally, the abundance of the main Babesia canis vector, the Dermacentor reticulatus tick, was estimated and monitored during a 4-year period (2008–2012) close to the dog kennel. The abundance of questing ticks was high in 2008 and 2009, but dropped by 10-fold between 2010 and 2012, when the abandoned meadow was cut and used as horse pasture by the local farmer. The regular occurrence, typical seasonal pattern and identification of B. canis DNA in questing tick from this locality confirmed the establishment of a new hyper enzootic region for canine babesiosis. The effectiveness and schedule of applied preventive measures were discussed.

Changes in the activity of adult stages of Dermacentor reticulatus (Ixodida: Amblyommidae) induced by weather factors in eastern Poland.

BackgroundThe host-seeking activity in Dermacentor reticulatus ticks undergoes rhythmical changes correlated with environmental conditions. Therefore, this study is focused on investigating the activity of adult stages of the species during weather changes occurring in winter months in eastern Poland, i.e. a period of tick diapause.MethodsD. reticulatus ticks were collected in a meadow ecosystem near Lublin (eastern Poland, 51°36'N, 22°58'E) between the third decade of November 2011 and the third decade of January 2012. During each collection, temperature and humidity were measured at the soil surface and at a height of 25 cm and the differences (delta) in the parameters between the two measurement points were calculated.ResultsDuring one hour of our observation, from 0 to 42 specimens were collected, with the greatest numbers (25-40 specimens) between late November and mid- December. The activity of adult D. reticulatus (females and males in total) depended on soil and air temperature (r = -0.6986, p < 0.05). Soil and air humidity did not exert an impact on the questing behaviour of adult stages. In turn, the greater the moisture delta between these two measurement points was, the greater the activity of the adult tick stages was observed.Our investigations have demonstrated differences in the questing behaviour between D. reticulatus females and males correlated with environmental conditions. The temperatures of soil and air increased the migratory activity in females but did not affect migration of male ticks. In turn, the deltas of temperatures (r = -0.6986, p < 0.05) and humidity (r = 0.6829, p < 0.05) did not have a statistically significant effect on stimulation of female activity but they induced significant changes on the behaviour of males, for which we found a highly negative correlation between the number of active specimens and the temperature delta (r = -0.7276, p < 0.05) and a highly positive correlation with the humidity delta (r = 0.8199, p < 0.01).ConclusionsWeather changes can be accompanied by activity of adult D. reticulatus even in their winter diapause period. Therefore, there is an increased threat to human and animal health posed by tick-borne diseases.

The ability of an oral formulation of afoxolaner to block the transmission of Babesia canis by Dermacentor reticulatus ticks to dogs.

BackgroundCanine babesiosis due to Babesia canis is an endemic disease in many European countries. A vaccine is available in some countries, but it does not prevent the infection and just helps in reducing the gravity of clinical signs. Therefore, the major way to help preventing the disease is by controlling tick infestations on dogs.To assess the preventive efficacy of afoxolaner (NexGard®), a new oral anti- flea and tick product, against Babesia canis infected adult Dermacentor reticulatus in an experimentally controlled study.MethodsSixteen healthy mixed breed adult dogs, negative for Babesia canis antibodies were included in a single centre, randomized, blinded and controlled study to evaluate the impact of treatment with afoxolaner on the transmission of Babesia canis to dogs exposed to Dermacentor reticulatus. The dogs were randomly allocated into two groups of 8 dogs each. One group remained untreated. In the other group, dogs were treated orally with a novel formulation of afoxolaner (NexGard®) on day 0. All dogs were infested each by 50 adult Dermacentor reticulatus ticks (equal sex ratio) at days 7, 14, 21 and 28. The Dermacentor reticulatus ticks were confirmed to harbour Babesia canis by Polymerase Chain Reaction (PCR).ResultsThe treatment was well tolerated by all dogs without any adverse effects. Babesia canis was transmitted by D. reticulatus to all untreated control dogs, confirmed following demonstration of hyperthermia, detection of B. canis parasites in blood smears and PCR assay from blood and serology. These confirmed infected dogs were subsequently treated with imidocarb and diminazene. The treated dogs remained negative based on all criteria until the last study, Day 56, confirming that the oral treatment of dogs with NexGard® prevented transmission of Babesia canis and development of clinical babesiosis for up to 28 days.ConclusionThis is the first demonstration that an oral acaricidal treatment may prevent the transmission of a pathogen despite the need for the tick to attach and start feeding before being killed by the acaricide.

The deduced evolution history of Omsk hemorrhagic fever virus

Omsk hemorrhagic fever (OHF) is a severe disease that emerged in the 1940s in Siberia, Russia. It is caused by the OHF virus (OHFV), belonging to the Flavivirus genus. In wildlife, the principal vector of OHFV is the Dermacentor reticulatus tick. However, humans are mainly infected after contact with an infected muskrat Ondatra zibethicus. The evolutionary history of OHFV is not yet clarified. In an attempt to reconstruct the temporal and spatial phylodynamics of OHFV, a collection of 25 OHFV strains was studied. Maximum likelihood analysis, the Bayesian MCMC approach, and procedures based on continuous-time Markov Chain process, were used for the investigation of OHFV E gene nucleotide sequences. Six statistically supported clusters of OHFV were identified; five of them joined in a main clade A. The first revealed evolutionary event, when OHFV clade A and clade B divided, dated to about 700 years ago. Clusters C, D, and E, within clade A, separated 230 years ago and further evolved during last century. The phylogeographic analysis showed that clade A originated in the Omsk Province, whereas clusters B, C, and E appeared to originate in Kurgan, Novosibirsk, and Omsk Provinces, respectively. In conclusion, OHFV, as a member of the mammalian tick-borne group of flaviviruses, evolved in Western Siberia during the last millennium. When a highly susceptible species, O.zibethicus, was introduced into the region, in the 1930s, OHFV used this species as an amplifying host that lead to numerous fatal epizootics in muskrats and to human OHF outbreaks.

Questing Dermacentor reticulatus harbouring Babesia canis DNA associated with outbreaks of canine babesiosis in the Swiss Midlands

In 2011 and 2012, outbreaks of clinical canine babesiosis were observed in 2 areas of the Swiss Midlands that had no history of this disease so far. In one area, cases of canine babesiosis occurred over 2 consecutive tick seasons. The outbreaks involved 29 dogs, 4 of which died. All dogs were infected with large Babesia sp. as diagnosed in Giemsa-stained blood smears and/or PCR. These were identified as B. canis (formerly known as B. canis canis) by subsequent partial sequencing of the 18S rRNA gene of Babesia sp. Interestingly, the sequence indicated either a genotype with heterogeneity in the ssrRNA gene copies or double infection with different B. canis isolates. None of the dogs had a recent travel history, but one had frequently travelled to Hungary and had suffered twice from clinical babesiosis 18 and 24 months prior to the outbreak in autumn 2011. Retrospective sequencing of a stored blood DNA sample of this dog revealed B. canis, with an identical sequence to the Babesia involved in the outbreaks.For the first time in Switzerland, the partial 18S rRNA gene of B. canis could be amplified from DNA isolated from 19 out of 23 adult Dermacentor reticulatus ticks flagged in the same area. The sequence was identical to that found in the dogs. Furthermore, one affected dog carried a female D. reticulatus tick harbouring B. canis DNA. Our findings illustrate that, under favourable biogeographic and climatic conditions, the life-cycle of B. canis can relatively rapidly establish itself in previously non-endemic areas. Canine babesiosis should therefore always be a differential diagnosis when dogs with typical clinical signs are presented, regardless of known endemic areas.

Prevalence of Tick-Borne Pathogens in Ixodes ricinus and Dermacentor reticulatus Ticks from Different Geographical Locations in Belarus

Worldwide, ticks are important vectors of human and animal pathogens. Besides Lyme Borreliosis, a variety of other bacterial and protozoal tick-borne infections are of medical interest in Europe. In this study, 553 questing and feeding Ixodes ricinus (n = 327) and Dermacentor reticulatus ticks (n = 226) were analysed by PCR for Borrelia, Rickettsia, Anaplasma, Coxiella, Francisella and Babesia species. Overall, the pathogen prevalence in ticks was 30.6% for I. ricinus and 45.6% for D. reticulatus. The majority of infections were caused by members of the spotted-fever group rickettsiae (24.4%), 9.4% of ticks were positive for Borrelia burgdorferi sensu lato, with Borrelia afzelii being the most frequently detected species (40.4%). Pathogens with low prevalence rates in ticks were Anaplasma phagocytophilum (2.2%), Coxiella burnetii (0.9%), Francisella tularensis subspecies (0.7%), Bartonella henselae (0.7%), Babesia microti (0.5%) and Babesia venatorum (0.4%). On a regional level, hotspots of pathogens were identified for A. phagocytophilum (12.5–17.2%), F. tularensis ssp. (5.5%) and C. burnetii (9.1%), suggesting established zoonotic cycles of these pathogens at least at these sites. Our survey revealed a high burden of tick-borne pathogens in questing and feeding I. ricinus and D. reticulatus ticks collected in different regions in Belarus, indicating a potential risk for humans and animals. Identified hotspots of infected ticks should be included in future surveillance studies, especially when F. tularensis ssp. and C. burnetii are involved.

Tick cell culture isolation and growth of Rickettsia raoultii from Dutch Dermacentor reticulatus ticks

Tick cell lines play an important role in research on ticks and tick-borne pathogenic and symbiotic microorganisms. In an attempt to derive continuous Dermacentor reticulatus cell lines, embryo-derived primary cell cultures were set up from eggs laid by field ticks originally collected as unfed adults in The Netherlands and maintained for up to 16 months. After several months, it became evident that cells in the primary cultures were infected with a Rickettsia-like intracellular organism. Supernatant medium containing some D. reticulatus cells was inoculated into cultures of 2 Rhipicephalus (Boophilus) microplus cell lines, BME/CTVM2 and BME/CTVM23, where abundant growth of the bacteria occurred intracellularly on transfer to both cell lines. Bacterial growth was monitored by light (live, inverted microscope, Giemsa-stained cytocentrifuge smears) and transmission electron microscopy revealing heavy infection with typical intracytoplasmic Rickettsia-like bacteria, not present in uninfected cultures. DNA was extracted from bacteria-infected and uninfected control cultures, and primers specific for Rickettsia 16S rRNA, ompB, and sca4 genes were used to generate PCR products that were subsequently sequenced. D. reticulatus primary cultures and both infected tick cell lines were positive for all 3 Rickettsia genes. Sequencing of PCR products revealed 99–100% identity with published Rickettsia raoultii sequences. The R. raoultii also grew abundantly in the D. nitens cell line ANE58, poorly in the D. albipictus cell line DALBE3, and not at all in the D. andersoni cell line DAE15. In conclusion, primary tick cell cultures and cell lines are useful systems for isolation and propagation of fastidious tick-borne microorganisms. In vitro isolation of R. raoultii from Dutch D. reticulatus confirms previous PCR-based detection in field ticks, and presence of the bacteria in the tick eggs used to initiate the primary cultures confirms that transovarial transmission of this Rickettsia occurs.

Presence of an emerging subclone of Francisella tularensis holarctica in Ixodes ricinus ticks from south-western Germany

The zoonotic disease tularaemia is caused by the bacterial pathogen Francisella tularensis. Although the causative agent is known for 100 years, knowledge of its enzootic cycles is still rudimentary. Apart from tabanids and mosquitoes, hard ticks have been described as important vectors and potential reservoirs for F. tularensis. Available data on the incidence of human tularaemia indicate an increase in cases in the federal state of Baden-Wuerttemberg. To determine whether ticks are involved in the reported increase in F. tularensis infections in humans and wildlife in this south-western part of Germany, 916 Ixodes ricinus and 211 adult Dermacentor marginatus and D. reticulatus ticks were collected in two different locations. Screening for the presence of F. tularensis was performed by real-time PCR of the 16S rRNA gene. Of the 95 pools of I. ricinus ticks (representing 916 individual ticks), 8 tick pools (8.4%) were positive in this PCR. 30-bp deletion PCR confirmed that the F. tularensis subspecies holarctica was present. FtM24 VNTR analysis revealed that they belong to the emerging Franco-Iberian subclone group of F. tularensis holarctica. Of the 211 ticks of the genus Dermacentor, 35 randomly chosen DNAs were subjected to 16S rRNA gene screening PCR; 20 of these (57%) gave positive signals. For cluster analysis, the lpnA gene region of all Francisella-positive I. ricinus pools and 6 Dermacentor ticks with a positive reaction in the screening PCR was amplified and sequenced. In the resulting neighbour-joining tree, all Francisella-positive I. ricinus samples clustered with sequences of F. tularensis, whilst all Dermacentor tick samples clustered with FLE (Francisella-like endosymbiont) sequences. This study shows that I. ricinus ticks may serve as vectors and/or reservoirs of F. tularensis in Germany and supports the hypothesis that the state of Baden-Wuerttemberg represents an emerging endemic focus of tularaemia.

Prevention of transmission of Babesia canis by Dermacentor reticulatus ticks to dogs treated with an imidacloprid/flumethrin collar

A group of 8 dogs was treated with an imidacloprid/flumethrin collar (Seresto®) 28 days prior to infestation with adult Dermacentor reticulatus ticks, infected with Babesia canis. The ability of the collar to prevent transmission of B. canis in the treated group was compared to an untreated control group. All 8 dogs in the untreated control group became infected with B. canis parasites, which were detected in blood smears as early as day 6 post tick-application. All control dogs developed clinical signs of babesiosis and were rescue-treated with imidocarb dipropionate. These dogs also developed specific B. canis antibodies as identified by serology (IFA test) and were confirmed PCR/RLB positive.None of the 8 dogs treated with the imidacloprid/flumethrin collar became infected with B. canis, which was confirmed by the absence of specific B. canis antibodies and babesial DNA as confirmed by PCR/RLB.The collar caused 96.02% of the ticks to die within 48h post challenge and this increased to 100% within 4 days. Although a high percentage of 44% of the Dermacentor ticks were infected with B. canis, they were unable to transmit the infection to the treated group. Hence, the imidacloprid/flumethrin collar effectively prevented transmission of B. canis 1 month after application onto the dogs.

Evidence for an increased distribution range of Dermacentor reticulatus in south-west Poland

The expansion of Dermacentor reticulatus to new geographical areas has been observed in several countries in Europe, including Poland and it’s neighbors. In 2011 and 2012, a total of 148 host-seeking D. reticulatus ticks were collected after flagging the vegetation in Lower Silesia, south-western Poland. Tick monitoring was conducted in mixed and deciduous forest, on meadows, in river valleys and ecotones between forested and grassy areas. The ornate dog ticks were found in 10 out of 33 sites located in five districts: Legnica, Wroclaw, Środa Śląska, Lubin and Boleslawiec County. All sites where D. reticulatus ticks were found are located to the south-west of the Odra River. The greatest distance between these disconnected localities was approximately 90 km. It seems that at present the southern boundary of the range is Wroclaw district. This study indicates that D. reticulatus can be ranked as a typical element of the fauna in Lower Silesia in southwestern Poland.

Identification of salivary antigenic markers discriminating host exposition between two European ticks: Rhipicephalus sanguineus and Dermacentor reticulatus

To succeed blood meal, ticks inject salivary proteins to mammalian hosts, eliciting an antibody response against these foreign antigens. Although this immune response has been proposed as a surrogate marker of exposure to tick bites, identification of the corresponding antigens remains elusive. For this aim, a comparison by immunoblots of the kinetic IgG responses to protein salivary gland extracts from two European tick species, Rhipicephalus sanguineus or Dermacentor reticulatus, in rabbits was performed. A singularity in the immune patterns was observed according to rabbit exposure status and depending on the antigen source. Six and five bands were found specifically associated to R. sanguineus and to D. reticulatus exposures, respectively. The identity of these salivary antigenic proteins was determined using an original immunoproteomic approach. The utilization of these tick salivary proteins as biomarker candidates to discriminate R. sanguineus and/or D. reticulatus tick exposure or to develop anti-tick vaccines is discussed.

Absence of Borrelia spp., Candidatus Neoehrlichia mikurensis, and Anaplasma phagocytophilum in questing adult Dermacentor reticulatus ticks

To determine whether Dermacentor reticulatus ticks are infected by Borrelia spp., Candidatus Neoehrlichia mikurensis, or Anaplasma phagocytophilum, we collected questing adults in the outskirts of Berlin, Germany, examined them for the presence of DNA of these pathogens, and compared the infection rates to those of sympatric Ixodes ricinus ticks. Questing D. reticulatus adults appeared not to harbor the bacterial pathogens that are prevalent in I. ricinus ticks. Based on our sample size, the estimated prevalence of each of these pathogens in D. reticulatus ticks would be well below three tenth of a percent (<0.3%). For pathogens which so rarely infect D. reticulatus ticks, this tick likely plays no epidemiologic vector role for either their enzootic transmission cycle in nature or their transmission to people.

Genetic Polymorphism of 12S rRNA Gene amongDermacentor reticulatusFabricius Ticks in the Chernobyl Nuclear Power Plant Exclusion Zone

The molecular genetic variability of the 12S rRNA gene, on the basis of partial primary sequence and in silico-predicted secondary structures among Dermacentor reticulatus (Fabricius 1794) ticks, was studied in the Chernobyl Nuclear Power Plant (ChNPP) Exclusion Zone. In total, 20, 20, and 25 ethanol-preserved specimens, previously collected at 3 sites with 0.76, 1.91, and 4.5 millisievert (mSv)/hr ionizing radiation background, were examined. The primary sequence analysis generated 4 haplotypes defined by 3 polymorphic sites. The most common haplotype 1 was found in all 3 locations, representing 86.2% of all sampled individuals. Haplotype 4 (10.8%) was detected at the 1.91 and 4.50 mSv/hr sites. The unique haplotypes 2 (1.5%) and 3 (1.5%) were detected only at the 1.91 and 4.50 mSv/hr sites, respectively. The haplotype diversity, nucleotide diversity, and pairwise nucleotide differences for 2 tick populations at the 1.90 and 4.50 mSv/hr sites were 0.279, 0.00085, and 0.289, and 0.397, 0.00122, 0.413, respectively. No polymorphism was detected in ticks collected at the 0.76 mSv/hr site. The primary sequences of 12S rRNA were folded into the secondary structures and the free energy of haplotypes was calculated. The free energy at 37 C (ΔG) of the nonmutant haplotype 1 and the mutant haplotypes 2, 3, and 4 were -45.79, -44.17, -39.56, and -45.79 kcal/mol, respectively. Considering the correlation between the structural profile similarity of 12S rRNA and point mutations, haplotypes 1 and 4 have similar secondary structure profiles and have received a 0.999219 similarity score in the cluster tree. The unique haplotypes 2 and 3 have differences in the secondary structure in comparison with haplotypes 1 and 4; the similarity scores were 0.914747 and 0.169431, respectively. Further studies using more genetic markers are warranted to ascertain the genetic variability and population genetic structure within D. reticulatus tick populations in the ChNPP Exclusion Zone and to resolve their vector capacity.

Dynamics of tick infestations in foxes in Thuringia, Germany

This study aimed to provide up-to-date information on the dynamics of tick infestations on foxes in Thuringia, as the most recent information available was published in 1997. Fox carcasses that had been sent to the Thuringian State Authority for Food Safety and Consumer Protection (Thüringer Landesamt für Lebensmittelsicherheit und Verbraucherschutz – TLLV), between January 1st and December 31st, 2009, were examined for the presence of ticks. All ticks collected were stored at −20°C before being identified and classified according to their developmental stage and sex. Out of a total of 1286 foxes examined, 989 (76.9%) were infested with ticks. A total of 13,227 ticks were collected from the foxes. The stage most frequently found was the larva (48.1%), followed by the adult (34.1%), and the nymphal stage (17.8%). Regarding the adult stage, Ixodes ricinus was the most frequent tick species detected (82.2%), followed by I. canisuga (10.8%) and I. hexagonus (6.7%). Dermacentor reticulatus ticks were very rare (0.3%). With regard to nymphs, I. canisuga and I. hexagonus were the most frequent tick species found, and this was also assumed for the larval stage. The results indicate the occurrence of tick infestations in foxes throughout the year, mainly by I. ricinus, I. canisuga, and I. hexagonus, with seasonal variations. Foxes were infested by I. ricinus ticks significantly more frequently from April to September. This applied to all tick developmental stages, but especially to adults. In contrast to I. ricinus, the infestation of foxes with I. canisuga and I. hexagonus was significantly higher from January to March and from October to December, especially with the immature developmental stages.

Babesia microtiin AdultDermacentor reticulatusTicks from Eastern Poland

A total of 468 adult Dermacentor reticulatus ticks (298 females and 170 males) collected by flagging in the forests of Lubelskie province, eastern Poland, were analyzed by PCR and nested-PCR for the presence of Babesia microti DNA. In all, 21 ticks (4.5%) were found to be infected with B. microti. The infection rate in females (5.0%) was slightly greater than in males (3.5%). Detection of B. microti for the first time in adult D. reticulatus ticks suggests that this species should be considered as a potential vector of B. microti in Europe.

Abundance of Adult Ticks (Acari: Ixodidae) in the Chernobyl Nuclear Power Plant Exclusion Zone

The Chernobyl nuclear disaster resulted in contamination of vast areas in Europe. To date, there is little knowledge about the effects of radioactive contamination on tick species. We sampled ticks from vegetation and large-sized wild mammals belonging to orders Carnivora and Artiodactyla at sites with 0.76, 1.91, and 4.50 mSv/hr ionizing radiation background values in the Polesky State Radio-Ecological Reserve of the Chernobyl nuclear disaster zone in spring 2010. Altogether, 122 questing ticks were collected from vegetation. Among collected ticks, Dermacentor reticulatus (Fabricius) was, by far, the most abundant species (99.2%), followed by Ixodes ricnus (L.) (0.8%), which was collected only at the 0.76 mSv/hr site. The average sex ratio female∶male was 2.9∶1.0. In parallel with the present study, we examined 3 Sus scrofa (L.), 2 Nyctereutes procyonoides (Gray), and 1 Alces alces (L.) at the 4.50 mSv/hr site; 96 D. reticulatus ticks were found on 2 N. procyonoides specimens. The mean density and the intensity of infestation were 16 ticks per animal and 48 ticks per infested animal, respectively. Future investigations are warranted to further characterize the role of various tick vectors, vertebrate reservoirs, and diversity of tick-borne pathogens in the Chernobyl exclusion zone.