Species, developmental stage and infection with microbial pathogens of engorged ticks removed from dogs and questing ticks

Co-Occurrence of Borrelia burgdorferi Sensu Lato and Babesia spp. DNA in Ixodes ricinus Ticks Collected from Vegetation and Pets in the City of Poznań, Poland

Here, we described the prevalence of Borrelia burgdorferi s.l. and Babesia species found in mono- and double infections among Ixodes ricinus ticks occurring in urban areas of the city of Poznań, Poland. We tested 1029 host-seeking ticks and 1268 engorged ticks removed from pet animals. Borrelia afzelii and B. garinii prevailed both in ticks from vegetation (3.7% and 3.7%, respectively) and from pets (3.7% and 0.6%, respectively). Babesia canis and Ba. microti were the most prevalent in host-seeking (2.6% and 1.4%, respectively) and feeding ticks (2.8% and 2.2%, respectively). Babesia microti sequences proved to be identical to the human pathogenic Ba. microti genotype "Jena/Germany". Sequences of the rarest piroplasm Ba. venatorum (0.7%) were identical with those isolated from European patients. About 1.0% of tested ticks yielded dual infections; in host-seeking ticks, Ba. canis prevailed in co-infections with B. afzelii and B. garinii, whereas Ba. microti and B. afzelii dominated in double-infected feeding ticks. Dual infections, even with a low prevalence, pose a challenge for differential diagnosis in patients with acute febrile disease after a tick bite. The finding of Ba. canis in both tick groups suggests that I. ricinus could be involved in the circulation of this piroplasm.

Canine Babesiosis Caused by Large Babesia Species: Global Prevalence and Risk Factors-A Review

Canine babesiosis is a disease caused by protozoan pathogens belonging to the genus Babesia. Four species of large Babesia cause canine babesiosis (B. canis, B. rossi, B. vogeli, and the informally named B. coco). Although canine babesiosis has a worldwide distribution, different species occur in specific regions: B. rossi in sub-Saharan Africa, B. canis in Europe and Asia, and B. coco in the Eastern Atlantic United States, while B. vogeli occurs in Africa, southern parts of Europe and Asia, northern Australia, southern regions of North America, and in South America. B. vogeli is the most prevalent large Babesia species globally. This results from its wide range of monotropic vector species, the mild or subclinical nature of infections, and likely the longest evolutionary association with dogs. The most important risk factors for infection by large Babesia spp. include living in rural areas, kennels or animal shelters, or regions endemic for the infection, the season of the year (which is associated with increased tick activity), infestation with ticks, and lack of treatment with acaricides.

Canine babesiosis in Austria in the 21st century - A review of cases

A retrospective study on 699 cases of canine babesiosis presented to veterinary clinics in eastern Austria were evaluated for the location where infection had presumably taken place. Of these, 542 (77.54%) had acquired the infection in Austria, while the majority of non-autochthonous cases came from neighboring countries, most notable Hungary. Both groups were recorded primarily in Vienna, eastern Lower Austria and Burgenland, but cases from the southern (Styria, Carinthia) and western (Upper Austria, Tyrol, Salzburg) provinces of the country were also recorded. Records were made all year round, with most cases in spring (46.6%) and fall (48.4%). The annual cases ranged from four to 58 (mean: 31.8) with large fluctuations and no visible trend for an in- or decrease. The tick vector of Babesia canis, Dermacentor reticulatus, is present in Austria but displays a very patchy distribution, and its occurrence and activity are not readily foretold, which might be a reason why its presumably increasing density in Europe is not reflected by increased incidences of canine babesiosis. Another factor that may influence the numbers of cases per year could be the application (or non-application) of acaricidal or repellent compounds. A limitation of this study is that bias is exerted by the location of the participating clinics, and by the unknown rate of infections that does not induce clinical symptoms and is likely not presented in veterinary practices and clinics. The data, however, clearly show that at least the lowlands of Austria are endemic for B. canis, and appropriate tick control must be advised all year round.

Tick feeding modulates the human skin immune landscape to facilitate tick-borne pathogen transmission

During cutaneous tick attachment, the feeding cavity becomes a site of transmission for tick salivary compounds and tick-borne pathogens. However, the immunological consequences of tick feeding for human skin remain unclear. Here, we assessed human skin and blood samples upon tick bite and developed a human skin explant model mimicking Ixodes ricinus bites and tick-borne pathogen infection. Following tick attachment, we observed rapidly occurring patterns of immunomodulation, including increases in neutrophils and cutaneous B and T cells. T cells upregulated tissue residency markers, while lymphocytic cytokine production was impaired. In early stages of Borrelia burgdorferi model infections, we detected strain-specific immune responses and close spatial relationships between macrophages and spirochetes. Preincubation of spirochetes with tick salivary gland extracts hampered accumulation of immune cells and increased spirochete loads. Collectively, we showed that tick feeding exerts profound changes on the skin immune network that interfere with the primary response against tick-borne pathogens.

Babesiosis in Southeastern, Central and Northeastern Europe: An Emerging and Re-Emerging Tick-Borne Disease of Humans and Animals

There is now considerable evidence that in Europe, babesiosis is an emerging infectious disease, with some of the causative species spreading as a consequence of the increasing range of their tick vector hosts. In this review, we summarize both the historic records and recent findings on the occurrence and incidence of babesiosis in 20 European countries located in southeastern Europe (Bosnia and Herzegovina, Croatia, and Serbia), central Europe (Austria, the Czech Republic, Germany, Hungary, Luxembourg, Poland, Slovakia, Slovenia, and Switzerland), and northern and northeastern Europe (Lithuania, Latvia, Estonia, Iceland, Denmark, Finland, Sweden, and Norway), identified in humans and selected species of domesticated animals (cats, dogs, horses, and cattle). Recorded cases of human babesiosis are still rare, but their number is expected to rise in the coming years. This is because of the widespread and longer seasonal activity of Ixodes ricinus as a result of climate change and because of the more extensive use of better molecular diagnostic methods. Bovine babesiosis has a re-emerging potential because of the likely loss of herd immunity, while canine babesiosis is rapidly expanding in central and northeastern Europe, its occurrence correlating with the rapid, successful expansion of the ornate dog tick (Dermacentor reticulatus) populations in Europe. Taken together, our analysis of the available reports shows clear evidence of an increasing annual incidence of babesiosis across Europe in both humans and animals that is changing in line with similar increases in the incidence of other tick-borne diseases. This situation is of major concern, and we recommend more extensive and frequent, standardized monitoring using a "One Health" approach.

Maps of ticks (Acari: Argasidae, Ixodidae) for Austria and South Tyrol, Italy

A first compilation of georeferenced tick locations in Austria and South Tyrol, Italy, is presented here. This allows the tick fauna to be examined in the various climatic regions of the European Alps. The dataset comprises 424 tick locations of Austria and 48 tick locations of South Tyrol, which were digitized from literature and visualized in the form of geographical maps. The tick fauna of Austria includes two species of Argasidae in the genera Argas and Carios and 15 species of Ixodidae in the genera Dermacentor, Haemaphysalis, and Ixodes, altogether 17 tick species. In addition, two species of Ixodidae in the genera Hyalomma (each spring imported by migratory birds) and Rhipicephalus (occasionally imported by dogs returning from abroad with their owners) are included in the tick atlas. Of these, the georeferenced locations of 18 tick species are depicted in maps. The occurrence of the one remaining tick species, Ixodes inopinatus, is given at the level of the federal states. The first Austrian distribution map of the long-legged bat tick Ixodes vespertilionis, which was reported from 21 caves, deserves special mention. The most common and widespread tick species is Ixodes ricinus, with records in all nine federal states of Austria, followed by Ixodes canisuga, Ixodes hexagonus, and I. vespertilionis in six federal states each. Haemaphysalis concinna and Dermacentor reticulatus are only endemic in the eastern plains, while Dermacentor marginatus only occurs in the west, in the Tyrolean Alpine valleys. Eight tick species were reported from South Tyrol, Italy. There, the most frequently flagged tick from the vegetation is also I. ricinus, while D. marginatus and Haemaphysalis punctata are often collected from sheep. The locations are shown together with those from North and East Tyrol on a separate Tyrol map. The tick atlas in Austria and South Tyrol as well as the underlying digital dataset in the supplement contribute to the closing of data gaps in global distribution maps of ticks and improve the data basis for new species distribution models.

Co-infection with Babesia canis and Babesia gibsoni in a dog

A four-year-old intact male Boxer, that had a history of travelling to Serbia, was referred for lethargy and anaemia. Shortly before the dog was referred, it was diagnosed twice with an infection with Babesia canis and was treated with imidocarb both times. A blood smear evaluation was indicative of the presence of intraerythrocytic piroplasms. After receiving inconclusive results regarding the type of piroplasm, the dog was diagnosed with simultaneous infections with B. canis and Babesia gibsoni via real-time polymerase chain reaction (rt-PCR) testing. The dog was treated with imidocarb, atovaquone and azithromycin, and in a follow-up examination, the PCR results were negative for B. canis and B. gibsoni. Several weeks later, the dog was presented again, and a PCR was positive for B. gibsoni. After atovaquone and azithromycin failed to eliminate the parasites, a therapy attempt using metronidazole, clindamycin and doxycycline was initiated. Six months after diagnosis, the treatment appeared successful in eliminating B. gibsoni. This case report describes the clinical findings of the co-infection and the initiated diagnostic and therapeutic approaches.

The specificity of Babesia-tick vector interactions: recent advances and pitfalls in molecular and field studies

Background

Babesia spp. are protozoan parasites of great medical and veterinary importance, especially in the northern Hemisphere. Ticks are known vectors of Babesia spp., although some Babesia-tick interactions have not been fully elucidated.

Methods

The present review was performed to investigate the specificity of Babesia-tick species interactions that have been identified using molecular techniques in studies conducted in the last 20 years under field conditions. We aimed to indicate the main vectors of important Babesia species based on published research papers (n = 129) and molecular data derived from the GenBank database.

Results

Repeated observations of certain Babesia species in specific species and genera of ticks in numerous independent studies, carried out in different areas and years, have been considered epidemiological evidence of established Babesia-tick interactions. The best studied species of ticks are Ixodes ricinus, Dermacentor reticulatus and Ixodes scapularis (103 reports, i.e. 80% of total reports). Eco-epidemiological studies have confirmed a specific relationship between Babesia microti and Ixodes ricinus, Ixodes persulcatus, and Ixodes scapularis and also between Babesia canis and D. reticulatus. Additionally, four Babesia species (and one genotype), which have different deer species as reservoir hosts, displayed specificity to the I. ricinus complex. Eco-epidemiological studies do not support interactions between a high number of Babesia spp. and I. ricinus or D. reticulatus. Interestingly, pioneering studies on other species and genera of ticks have revealed the existence of likely new Babesia species, which need more scientific attention. Finally, we discuss the detection of Babesia spp. in feeding ticks and critically evaluate the data on the role of the latter as vectors.

Conclusions

Epidemiological data have confirmed the specificity of certain Babesia-tick vector interactions. The massive amount of data that has been thus far collected for the most common tick species needs to be complemented by more intensive studies on Babesia infections in underrepresented tick species.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-021-05019-3.

Infections with Tickborne Pathogens after Tick Bite, Austria, 2015-2018

Knowledge about outcomes of tick bites is crucial because infections with emerging pathogens might be underestimated.

The aim of this prospective study was to assess the risk for tickborne infections after a tick bite. A total of 489 persons bitten by 1,295 ticks were assessed for occurrence of infections with Borrelia burgdorferi sensu lato, Anaplasma phagocytophilum, Rickettsia spp., Babesia spp., Candidatus Neoehrlichia mikurensis, and relapsing fever borreliae. B. burgdorferi s.l. infection was found in 25 (5.1%) participants, of whom 15 had erythema migrans. Eleven (2.3%) participants were positive by PCR for Candidatus N. mikurensis. One asymptomatic participant infected with B. miyamotoi was identified. Full engorgement of the tick (odds ratio 9.52) and confirmation of B. burgdorferi s.l. in the tick by PCR (odds ratio 4.39) increased the risk for infection. Rickettsia helvetica was highly abundant in ticks but not pathogenic to humans. Knowledge about the outcome of tick bites is crucial because infections with emerging pathogens might be underestimated because of limited laboratory facilities.

Complications and risk factors regarding the outcomes of canine babesiosis in Central Europe - A retrospective analysis of 240 cases

The purpose of this study was to investigate retrospectively the prevalence of the complicated and uncomplicated forms of babesiosis and to evaluate various laboratory and clinical parameters of dogs infected with Babesia canis in order to assess their prognostic value regarding the outcomes of the disease. Medical records, complete blood count and serum biochemical analysis from the animal hospital information system of 240 dogs were reviewed and evaluated retrospectively. Binary logistic regression analysis was used to ascertain correlations between alterations in the obtained parameters and survival probability. The results showed that creatinine levels of more than 5 mg/dL and phosphate levels of more than 3 mmol/L have a highly significant link to death (P ≤ 0.001). Albumin levels of <2.2 g/dL (P = 0.003) and a rectal body temperature below 38 °C (P ≤ 0.001) may also serve as prognostic markers for the severity of the disease. If renal involvement was present, 33.9% of the dogs died, while 40.0% of the dogs died in the presence of pancreatitis. The parameters creatinine, phosphate, albumin and rectal temperature serve as reliable predictive markers of an increased risk of death in the case of an infection with B. canis.

Lyme Borreliosis with Scalp Eschar Mimicking Rickettsial Infection, Austria

We report on a patient in Austria with scalp eschar and neck lymphadenopathy. Rickettsial etiology was excluded by culture, PCR, and serologic tests. Borrelia afzelii was identified from the eschar swab by PCR. Lyme borreliosis can mimic rickettsiosis; appropriate tests should be included in the diagnostic workup of patients with eschars.

Vectors of disease at the northern distribution limit of the genus Dermacentor in Eurasia: D. reticulatus and D. silvarum

The two ixodid tick species Dermacentor reticulatus (Fabricius) and Dermacentor silvarum Olenev occur at the northern distribution limit of the genus Dermacentor in Eurasia, within the belt of [Formula: see text] latitude. Whilst the distribution area of D. reticulatus extends from the Atlantic coast of Portugal to Western Siberia, that of D. silvarum extends from Western Siberia to the Pacific coast. In Western Siberia, the distribution areas of the two Dermacentor species overlap. Although the two tick species are important vectors of disease, detailed information concerning the entire distribution area, climate adaptation, and proven vector competence is still missing. A dataset was compiled, resulting in 2188 georeferenced D. reticulatus and 522 D. silvarum locations. Up-to-date maps depicting the geographical distribution and climate adaptation of the two Dermacentor species are presented. To investigate the climate adaptation of the two tick species, the georeferenced locations were superimposed on a high-resolution map of the Köppen-Geiger climate classification. The frequency distribution of D. reticulatus under different climates shows two major peaks related to the following climates: warm temperate with precipitation all year round (57%) and boreal with precipitation all year round (40%). The frequency distribution of D. silvarum shows also two major peaks related to boreal climates with precipitation all year round (30%) and boreal winter dry climates (60%). Dermacentor silvarum seems to be rather flexible concerning summer temperatures, which can range from cool to hot. In climates with cool summers D. reticulatus does not occur, it prefers warm and to a lesser extent hot summers. Lists are given in this paper for cases of proven vector competence for various agents of both Dermacentor species. For the first time, the entire distribution areas of D. reticulatus and D. silvarum were mapped using georeferenced data. Their climate adaptations were quantified by Köppen profiles.

Long-term monitoring of the seasonal density of questing ixodid ticks in Vienna (Austria): setup and first results

The first long-term monitoring to document both activity and density of questing ixodid ticks in Vienna, Austria, is introduced. It was started in 2017 and is planned to run over decades. Such long-term monitorings are needed to quantify possible effects of climate change or to develop tick density forecast models. The monthly questing tick density at three sites has been observed by using a standardized sampling method by dragging an area of [Formula: see text] at each occasion. Popular recreational areas were chosen as study sites. These are the Prater public park, the wooded Kahlenberg, and a wildlife garden in Klosterneuburg. First results show a 3-year time series of nymphs and adults of the Ixodes ricinus species complex and Haemaphysalis concinna for the period 2017-2019. Whereas questing nymphs of the I. ricinus species complex were collected from February to November, H. concinna nymphs were only dragged from May to October. The peak of nymphal activity of the I. ricinus species complex was in May, that of H. concinna in August. In addition, a brief overview is given about ticks and tick-borne pathogens occurring in urban and suburban areas of Vienna.

Molecular characterization of Anaplasma and Ehrlichia in ixodid ticks and reservoir hosts from Palestine: a pilot survey

Tick-borne anaplasmosis and ehrlichiosis are clinically important emerging zoonoses usually overlooked by veterinarians and physicians alike. This study aimed at detecting and genetically characterizing Ehrlichia and Anaplasma species in ixodid ticks and their animal hosts from the West Bank, Palestine. A total of 723 ixodid ticks belonging to three genera (Rhipicephalus, Hyalomma, Haemaphysalis) were collected from dogs, sheep, goats and camels. In addition, 189 blood samples were collected from dogs, sheep, camels, horses and a goat from the West Bank, Palestine. All tick and blood samples were investigated for the presence of Anaplasma and Ehrlichia targeting a 345 bp fragment of the 16S rRNA gene followed by sequence analysis. The infection rate of Anaplasma spp. in ticks was 6.5% (47/723). Anaplasma platys was identified in 28% (13/47) of them. Whereas, based on a partial sequence (851 bp) of msp4 gene, 38% (18/47) were identified as A. ovis. The species of the remaining 16 positive samples (16/47, 34%) could not be identified. Simultaneously, the infection rate of Ehrlichia spp. in the ticks was 0.6% (4/723). Three of which were E. canis and one was Ehrlichia spp. The infection rate of A. platys in dogs' blood samples was 10% (13/135), while it was 1.5% (2/135) for E. canis. The infection rate of Anaplasma in sheep blood samples was 40% (19/47), out of which 26% (5/19) were caused by A. ovis as revealed by msp4-PCR. Implementation of purely-spatial analysis by saTScan for all cases of Anaplasma revealed two statistically significant clusters in two districts; Tubas town and Majdal-Bani-Fadil village on the western hills of the Jordan Valley. Most cases of Anaplasma (83%) were from rural areas where life cycle components (vector, host and reservoir) abundantly interact. This study is the first in Palestine to reveal the presence of Anaplasma and Ehrlichia in ticks, dogs and sheep providing crucial platform for future epidemiological surveys and control strategies in the country and region.

Geographical distribution, climate adaptation and vector competence of the Eurasian hard tick Haemaphysalis concinna

The ixodid tick Haemaphysalis concinna Koch, 1844 is a proven vector of tick-borne encephalitis (TBE) virus and Francisella tularensis, the causative agent of tularaemia. In the present study, up-to-date maps depicting the geographical distribution and climate adaptation of H. concinna are presented. A dataset was compiled, resulting in 656 georeferenced locations in Eurasia. The distribution of H. concinna ranges from the Spanish Atlantic coast to Kamchatka, Russia, within the belt of 28-64° N latitude. H. concinna is the second most abundant tick species after Ixodes ricinus collected from birds, and third most abundant tick species flagged from vegetation in Central Europe. To investigate the climate adaptation of H. concinna, the georeferenced locations were superimposed on a high-resolution map of the Köppen-Geiger climate classification. A frequency distribution of the H. concinna occurrence under different climates shows three peaks related to the following climates: warm temperate with precipitation all year round, boreal with precipitation all year round and boreal, winter dry. Almost 87.3 % of all H. concinna locations collected are related to these climates. Thus, H. concinna prefers climates with a warm and moist summer. The remaining tick locations were characterized as cold steppes (6.2%), cold deserts (0.8%), Mediterranean climates (2.7%) or warm temperate climates with dry winter (2.9%). In those latter climates H. concinna occurs only sporadically, provided the microclimate is favourable. Beyond proven vector competence pathogen findings in questing H. concinna are compiled from the literature.

Approaches for Reverse Line Blot-Based Detection of Microbial Pathogens in Ixodes ricinus Ticks Collected in Austria and Impact of the Chosen Method

Ticks transmit a large number of pathogens capable of causing human disease. In this study, the PCR-reverse line blot (RLB) method was used to screen for pathogens in a total of 554 Ixodes ricinus ticks collected from all provinces of Austria. These pathogens belong to the genera Borrelia, Rickettsiae, Anaplasma/Ehrlichia (including "Candidatus Neoehrlichia"), Babesia, and Coxiella The pathogens with the highest detected prevalence were spirochetes of the Borrelia burgdorferisensu lato complex, in 142 ticks (25.6%). Borrelia afzelii (80/142) was the most frequently detected species, followed by Borrelia burgdorferisensu stricto (38/142) and Borrelia valaisiana (36/142). Borrelia garinii/Borrelia bavariensis, Borrelia lusitaniae, and Borrelia spielmanii were found in 28 ticks, 5 ticks, and 1 tick, respectively. Rickettsia spp. were detected in 93 ticks (16.8%): R. helvetica (39/93), R. raoultii (38/93), R. monacensis (2/93), and R. slovaca (1/93). Thirteen Rickettsia samples remain uncharacterized. "Candidatus Neoehrlichia mikurensis," Babesia spp. (B. venatorum, B. divergens, B. microti), and Anaplasma phagocytophilum were found in 4.5%, 2.7%, and 0.7%, respectively. Coxiella burnetii was not detected. Multiple microorganisms were detected in 40 ticks (7.2%), and the cooccurrence of Babesia spp. and "Candidatus Neoehrlichia mikurensis" showed a significant positive correlation. We also compared different PCR-RLBs for detection of Borrelia burgdorferisensu lato and Rickettsia spp. and showed that different detection approaches provide highly diverse results, indicating that analysis of environmental samples remains challenging.IMPORTANCE This study determined the wide spectrum of tick-borne bacterial and protozoal pathogens that can be encountered in Austria. Surveillance of (putative) pathogenic microorganisms occurring in the environment is of medical importance, especially when those agents can be transmitted by ticks and cause disease. The observation of significant coinfections of certain microorganisms in field-collected ticks is an initial step to an improved understanding of microbial interactions in ticks. In addition, we show that variations in molecular detection methods, such as in primer pairs and target genes, can considerably influence the final results. For instance, detection of certain genospecies of borreliae may be better or worse by one method or the other, a fact of great importance for future screening studies.

Molecular diagnosis of African tick bite fever using eschar swabs in a traveller returning from Tanzania

African tick bite fever is an emerging infectious disease among travellers caused by the pathogen Rickettsia africae. Most travel-associated cases have been reported from countries in southern Africa. So far it has rarely been reported among travellers to eastern Africa and our patient is one of the first described cases imported from Tanzania. A woman presented with fever, chills, headache, myalgia and a rickettsial eschar on her ankle after returning from Tanzania. The diagnosis of African tick bite fever is often based on clinical grounds due to a lack of reliable diagnostic tests at commencement of symptoms. In this patient direct molecular detection of R. africae was performed by PCR from a sample obtained non-invasively with a swab from the rickettsial eschar. A positive PCR result was achieved although the patient had already started antibiotic treatment with doxycycline. In conclusion, this non-invasive method enables early diagnosis of African tick bite fever by direct molecular detection of R. africae and might improve the management of undifferentiated fever in travellers from Africa.

Detection of selected pathogens in ticks collected from cats and dogs in the Wrocław Agglomeration, South-West Poland

Background

Tick-borne infections are no longer confined to rural areas, they are documented with increasing frequency in urban settlements across the world. They are known to cause diseases in humans as well as in their companion animals.

Methods

During a period of 2 years, from January 2013 until December 2014, ticks were collected from dogs and cats in 18 veterinary clinics in the Wrocław Agglomeration, Poland. In total, 1455 ticks were found on 931 pets: 760 domestic dogs and 171 cats. For molecular examinations 127 I. ricinus ticks (115 females and 12 males) were randomly selected, all collected I. hexagonus (n = 137, 32 females, 98 nymphs, 7 larvae) and all collected D. reticulatus (n = 46, 31 females, 15 males) were taken. Ixodes ricinus and I. hexagonus ticks were tested for Rickettsia spp., Anaplasma phagocytophilum, Candidatus Neoehrlichia mikurensis and Babesia spp., while D. reticulatus ticks were investigated for Rickettsia spp. and Babesia spp. only.

Results

In total, 65.4 % I. ricinus ticks were infected with at least one pathogen. Over 50 % of I. ricinus were positive for Rickettsia spp. (R. helvetica and R. monacensis). The infection level with A. phagocytophilum was 21.3 %. DNA of Cand. N. mikurensis was detected in 8.1 % I. ricinus ticks. Interestingly only female ticks were infected. The prevalence of Babesia spp. was confirmed in 9.0 % of I. ricinus involving the species B. microti and B. venatorum. A total of nineteen double, one triple and two quadruple infections were found in I. ricinus ticks only. Almost 11 % of I. hexagonus ticks were positive for at least one of the tested pathogens. Rickettsia spp. infection was found in 2.2 %, while A. phagocytophilum was detected in 8.1 % of I. hexagonus ticks. Only one nymph was positive for Cand. N. mikurensis and none of I. hexagonus ticks harbored a Babesia spp. Over 60 % of D. reticulatus ticks were positive for rickettsial DNA, exclusively belonging to the species R. raoultii.

Conclusion

The high tick infestation rates and the prevalence of pathogens found in these ticks demonstrate a serious level of encounter to tick-borne diseases in urban dogs in the Wroclaw area, and provide evidence that dogs and cats themselves may substantially contribute to the circulation of the ticks and pathogens in the urban area.

Dermacentor reticulatus: a vector on the rise

Dermacentor reticulatus is a hard tick species with extraordinary biological features. It has a high reproduction rate, a rapid developmental cycle, and is also able to overcome years of unfavourable conditions. Dermacentor reticulatus can survive under water for several months and is cold-hardy even compared to other tick species. It has a wide host range: over 60 different wild and domesticated hosts are known for the three active developmental stages. Its high adaptiveness gives an edge to this tick species as shown by new data on the emergence and establishment of D. reticulatus populations throughout Europe. The tick has been the research focus of a growing number of scientists, physicians and veterinarians. Within the Web of Science database, more than a fifth of the over 700 items published on this species between 1897 and 2015 appeared in the last three years (2013–2015). Here we attempt to synthesize current knowledge on the systematics, ecology, geographical distribution and recent spread of the species and to highlight the great spectrum of possible veterinary and public health threats it poses. Canine babesiosis caused by Babesia canis is a severe leading canine vector-borne disease in many endemic areas. Although less frequently than Ixodes ricinus, D. reticulatus adults bite humans and transmit several Rickettsia spp., Omsk haemorrhagic fever virus or Tick-borne encephalitis virus. We have not solely collected and reviewed the latest and fundamental scientific papers available in primary databases but also widened our scope to books, theses, conference papers and specialists colleagues’ experience where needed. Besides the dominant literature available in English, we also tried to access scientific literature in German, Russian and eastern European languages as well. We hope to inspire future research projects that are necessary to understand the basic life-cycle and ecology of this vector in order to understand and prevent disease threats. We conclude that although great strides have been made in our knowledge of the eco-epidemiology of this species, several gaps still need to be filled with basic research, targeting possible reservoir and vector roles and the key factors resulting in the observed geographical spread of D. reticulatus.

Oligoarthritis caused by Borrelia bavariensis, Austria, 2014

A case of Lyme oligoarthritis occurred in an 11-year-old boy in Vienna, Austria. DNA of Borrelia bavariensis was detected by PCR in 2 aspirates obtained from different joints. Complete recovery was achieved after a 4-week course with amoxicillin. Lyme arthritis must be considered in patients from Europe who have persisting joint effusions.

Human granulocytic anaplasmosis acquired in Connecticut, USA, diagnosed in Vienna, Austria, 2015

Human granulocytic anaplasmosis (HGA) is caused by Anaplasma phagocytophilum, an intracellular pathogen transmitted by hard ticks. We report a patient who had acquired the infection in Connecticut, USA, and was diagnosed in Vienna, Austria, using PCR methods. Imported HGA from the United States to Austria is a rare event.

Geographical distribution of Dermacentor marginatus and Dermacentor reticulatus in Europe

The goal of this paper is to present up-to-date maps depicting the geographical distribution of Dermacentor species in Europe based on georeferenced sampling sites. Therefore, a dataset was compiled, resulting in 1286 D. marginatus (Sulzer, 1776) and 1209 D. reticulatus (Fabricius, 1794) locations. Special emphasis is given to the region of the European Alps depicting a presumable climate barrier of the mountains and to overlaps in the distribution of both species as well as on the situation in eastern European countries. For the latter newly described Dermacentor findings comprise 59 locations in Romania and 62 locations in Ukraine. The geographical distributions of both species in Europe range from Portugal to Ukraine (and continue to the east of Kazakhstan). Although it is well known that D. marginatus is adapted to a warmer and drier climate at more southern latitudes and D. reticulatus to a moderately moist climate at more northern latitudes, the distribution limits of both species were not well known. Here, the northern and southern distribution limits for both species in Europe, as determined from the georeferenced database, were specified for D. marginatus by the belt of 33-51° N latitude and for D. reticulatus by the belt of 41-57° N latitude. Thus, overlapping species distributions were found between 41° N and 51° N.

Wildlife reservoirs for vector-borne canine, feline and zoonotic infections in Austria

Austria's mammalian wildlife comprises a large variety of species, acting and interacting in different ways as reservoir and intermediate and definitive hosts for different pathogens that can be transmitted to pets and/or humans. Foxes and other wild canids are responsible for maintaining zoonotic agents, e.g. Echinococcus multilocularis, as well as pet-relevant pathogens, e.g. Hepatozoon canis. Together with the canids, and less commonly felids, rodents play a major role as intermediate and paratenic hosts. They carry viruses such as tick-borne encephalitis virus (TBEV), bacteria including Borrelia spp., protozoa such as Toxoplasma gondii, and helminths such as Toxocara canis. The role of wild ungulates, especially ruminants, as reservoirs for zoonotic disease on the other hand seems to be negligible, although the deer filaroid Onchocerca jakutensis has been described to infect humans. Deer may also harbour certain Anaplasma phagocytophilum strains with so far unclear potential to infect humans. The major role of deer as reservoirs is for ticks, mainly adults, thus maintaining the life cycle of these vectors and their distribution. Wild boar seem to be an exception among the ungulates as, in their interaction with the fox, they can introduce food-borne zoonotic agents such as Trichinella britovi and Alaria alata into the human food chain.

Pathogens in ticks collected from dogs in Berlin/Brandenburg, Germany

BACKGROUND

Tick-borne diseases are a major health risk for humans and dogs. In addition to collection and analysis of questing ticks, analysis of host-associated ticks for the presence of pathogens is a valuable method to gain insight into transmission patterns of tick-borne diseases.

METHODS

Ticks were collected from dogs living in the Berlin/Brandenburg area. The three tick species Ixodes ricinus, Ixodes hexagonus and Dermacentor reticulatus were examined for the presence of Babesia spp., Borrelia spp., Rickettsia spp. and Anaplasmataceae. Conventional PCR followed by sequencing was used for pathogen detection and characterization.

RESULTS

Babesia spp. were found in 2.5% and 3% of I. ricinus and I. hexagonus, respectively. Sequencing revealed the presence of Babesia microti, Babesia capreoli and Babesia venatorum. D. reticulatus were free of Babesia canis. Rickettsia spp. were detected in 61% of I. ricinus, 44% of I. hexagonus and 39% of D. reticulatus. Specifically detected were Rickettsia raoulti in D. reticulatus and I. hexagonus, Rickettsia helvetica in I. ricinus and I. hexagonus and Rickettsia monacensis in I. hexagonus. Anaplasma phagocytophilum and Candidatus Neoehrlichia mikurensis have been reported previously in I. ricinus (6.5% and 4.3%, respectively) and I. hexagonus (3.9% and 5.9%). Borrelia spp. were found in 11.6% of I. ricinus and 11.2% of I. hexagonus. Subsequent genospecies analysis revealed Borrelia afzelii, Borrelia garinii, Borrelia burgdorferi sensu stricto and Borrelia miyamotoi. Simultanous presence of more than one pathogen was found in 20% of I. ricinus and in 59% of I. hexagonus whereas the total frequency of any pathogen was 65% in I. ricinus, 59% in I. hexagonus and 64% in D. reticulatus. Ticks in which A. phagocytophilum was detected had a significantly increased risk of also containing Rickettsia. Ticks harbouring a pathogen had significantly higher scutal indices than ticks without presence of any pathogen.

CONCLUSIONS

Frequencies of potential human or canine pathogens in ticks were considerable and DNA of all four groups of pathogens was detected. Differences in scutal indices might suggest that pathogens are frequently taken up by ticks when feeding on dogs in Berlin/Brandenburg.

A look into the Medical and Veterinary Entomology crystal ball

Medical and Veterinary Entomology (MVE) represents a leading periodical in its field and covers many aspects of the biology and control of insects, ticks, mites and other arthropods of medical and veterinary importance. Since the first issue of the journal, researchers working in both developed and developing countries have published in MVE, with direct impact on current knowledge in the field. An increasing number of articles dealing with the epidemiology and transmission of vector-borne pathogens have been published in MVE, reflecting rapid changes in vector distribution, pathogen transmission and host-arthropod interactions. This article represents a gaze into the crystal ball in which we identify areas of increasing interest, discuss the main changes that have occurred in the epidemiology of parasitic arthropods since the first issue of MVE, and predict the principal scientific topics that might arise in the next 25 years for scientists working in medical and veterinary entomology.

Seasonal dynamics of Rhipicephalus rossicus attacking domestic dogs from the steppic region of southeastern Romania

Background

Danube Delta Biosphere Reserve is one of the most interesting regions in Europe from an epidemiological point of view due to its great biodiversity, local climatic conditions and various types of habitats. Moreover, there is no data regarding the ectoparasite communities of dogs from this area. In this frame, the aims of our study were to establish the tick communities parasitizing dogs and to provide new data regarding seasonal dynamics of a neglected tick species, Rhipicephalus rossicus.

Methods

A survey was carried out in order to gather information regarding tick species attaching to domestic dogs from a steppic region of southeastern Romania and to establish their seasonal dynamics. The research was conducted from 1 December 2012 to 30 November 2013, on 8 dogs from Iazurile, a locality from the west-central part of the Danube Delta Biosphere Reserve. In total, 384 examinations were made, each dog being checked for tick infestation 4 times per month, for one year.

Results

The 893 ticks found belonged to six species: R. rossicus (95.6%), Dermacentor reticulatus (3.2%), Ixodes ricinus (0.5%), Hyalomma marginatum (0.3%), Rhipicephalus sanguineus sensu lato (s.l.) (0.2%) and Ixodes crenulatus (0.1%). From the 91 positive examinations, R. rossicus was found in 80 (87.9%). Single species infestation occurred in 84 examinations. In 7 out of 91 positive examinations mixed infestation were found. No ticks were found in December, January and September.

Conclusions

For R. rossicus, high frequency and intensity were observed in May, June and July. The activity peaks for D. reticulatus were in spring and autumn. Our results highlight that within the range of R. sanguineus s.l., the most common dog tick worldwide, selected dog populations may be predominantly infested by closely related species, like in our case, R. rossicus.

Detection of Candidatus Neoehrlichia mikurensis, Borrelia burgdorferi sensu lato genospecies and Anaplasma phagocytophilum in a tick population from Austria

Candidatus Neoehrlichia mikurensis DNA was discovered in Ixodes ricinus ticks in 1999 and is referred to as an emerging human pathogen since its first detection in patients with febrile illness reported in 2010. In recent years, Ca. Neoehrlichia mikurensis has been detected in ticks from several European, Asian, and African countries. However, no epidemiological data exist for Austria, which is a highly endemic region for tick-transmitted diseases. To assess the geographic spread and prevalence of Ca. Neoehrlichia mikurensis sympatric with other tick-transmitted pathogens, we analysed 518 I. ricinus ticks collected in 2002 and 2003 in Graz, Austria. The prevalence of Ca. Neoehrlichia mikurensis was 4.2%, that of Borrelia burgdorferi sensu lato 25.7%, and that of Anaplasma phagocytophilum 1%. Coinfections with Ca. Neoehrlichia mikurensis and B. burgdorferi sensu lato were found in 2.3% of all ticks. Thus, the results show a relatively high prevalence of Ca. Neoehrlichia mikurensis in Austrian ticks suggesting a high probability for the occurrence of undiagnosed human infections in Austria.

Effect of owner-controlled acaricidal treatment on tick infestation and immune response to tick-borne pathogens in naturally infested dogs from Eastern Austria

BACKGROUND

Tick-borne infections resulting from regular tick infestation in dogs are a common veterinary health problem all over the world. The application of repellent and acaricidal agents to prevent transmission of pathogens is a major protection strategy and has been proven to be highly effective in several trials under laboratory and natural conditions in dogs. Despite such promising results, many dog owners still report tick infestation in their dogs although acaricidal agents are used. Information about the current infection status and changes of the infection status regarding tick-borne diseases (TBD) in dogs treated by the owner's controlled acaricide application is lacking.

METHODS

In this study 30 dogs were each treated with permethrin, fipronil + S-methoprene, or served as untreated controls. Application of the acaricide was performed by the owner who decided when and how often to use the spot on preparation. Over a period of 11 months, dogs were clinically examined and sampled for antibody responses against Babesia canis, Anaplasma phagocytophilum, Borrelia burgdorferi s. l., and TBE virus before the study started, 6 months later and at the end of the investigation period.

RESULTS

The permethrin acaricide was applied on average 3.40 times within the examination period, whereas the fipronil + S-methoprene medication was applied 3.03 times. Approximately 2/3 of all dogs, independent of the group, had a positive immune response to one or more pathogens. Three dogs developed clinical symptoms of canine babesiosis, all other dogs remained healthy. Individual number of ticks per dog or number of infections per dog did not correlate with the application rate, and the number of ticks per dog did not influence the number of infections per dog. As owners did not apply the acaricides regularly no influence on the number of infections could be documented although the number of ticks was clearly reduced by the application of the spot-on drugs.

CONCLUSIONS

Clinical disease in dogs exposed to tick-borne pathogens is rare, although a humoral immune response reflecting infection is common. More educational training for dog owners is necessary to make the application of acaricides effective regarding the prevention of tick-borne diseases.