Extensive examination of different tick species for infestation with Coxiella burnetii in Slovakia

Coxiella burnetii in Dogs and Cats from Portugal: Serological and Molecular Analysis

Dogs and cats are potential sources of infection for some zoonotic diseases such as Q fever, caused by Coxiella burnetii, a multiple host pathogen. Q fever outbreaks in dogs and cats have been related with parturition and abortion events, and ticks have a potential role in the transmission of this pathogen. This study aimed to screen for C. burnetii in dogs and cats, and in ticks collected from infested animals. An observational descriptive study was conducted in Portugal at two time points nine years apart, 2012 and 2021. Sera obtained from dogs and cats (total n = 294) were tested for C. burnetii antibodies using a commercial ELISA adapted for multi-species detection. C. burnetii DNA was screened by qPCR assay targeting IS1111 in uterine samples and in ticks. A decrease in the exposure to C. burnetii was observed in cats from 17.2% (95% CI: 5.8−35.8%) in 2012 to 0.0% in 2021, and in dogs from 12.6% (95% CI: 7.7−19.0%) in 2012 to 1.7% (95% CI: 0.3−9.1%) in 2021 (p < 0.05). Overall, and despite differences in the samples, rural habitat seems to favour the exposure to C. burnetii. The DNA of C. burnetii was not detected in ticks. The low seropositivity observed in 2021 and the absence of C. burnetii DNA in the tested samples, suggest that dogs and cats from Portugal are not often exposed to the pathogen. Nevertheless, the monitoring of C. burnetii infection in companion animals is an important tool to prevent human outbreaks, considering the zoonotic potential for owners and veterinarians contacting infected animals, mainly dogs and cats from rural areas which often come into contact with livestock.

What do we know about the microbiome of I. ricinus?

I. ricinus is an obligate hematophagous parasitic arthropod that is responsible for the transmission of a wide range of zoonotic pathogens including spirochetes of the genus Borrelia, Rickettsia spp., C. burnetii, Anaplasma phagocytophilum and Francisella tularensis, which are part the tick´s microbiome. Most of the studies focus on "pathogens" and only very few elucidate the role of "non-pathogenic" symbiotic microorganisms in I. ricinus. While most of the members of the microbiome are leading an intracellular lifestyle, they are able to complement tick´s nutrition and stress response having a great impact on tick´s survival and transmission of pathogens. The composition of the tick´s microbiome is not consistent and can be tied to the environment, tick species, developmental stage, or specific organ or tissue. Ovarian tissue harbors a stable microbiome consisting mainly but not exclusively of endosymbiotic bacteria, while the microbiome of the digestive system is rather unstable, and together with salivary glands, is mostly comprised of pathogens. The most prevalent endosymbionts found in ticks are Rickettsia spp., Ricketsiella spp., Coxiella-like and Francisella-like endosymbionts, Spiroplasma spp. and Candidatus Midichloria spp. Since microorganisms can modify ticks' behavior, such as mobility, feeding or saliva production, which results in increased survival rates, we aimed to elucidate the potential, tight relationship, and interaction between bacteria of the I. ricinus microbiome. Here we show that endosymbionts including Coxiella-like spp., can provide I. ricinus with different types of vitamin B (B2, B6, B7, B9) essential for eukaryotic organisms. Furthermore, we hypothesize that survival of Wolbachia spp., or the bacterial pathogen A. phagocytophilum can be supported by the tick itself since coinfection with symbiotic Spiroplasma ixodetis provides I. ricinus with complete metabolic pathway of folate biosynthesis necessary for DNA synthesis and cell division. Manipulation of tick´s endosymbiotic microbiome could present a perspective way of I. ricinus control and regulation of spread of emerging bacterial pathogens.

Coxiella burnetii in ticks, livestock, pets and wildlife: A mini-review

Coxiella burnetii is a zoonotic bacterium with an obligatory intracellular lifestyle and has a worldwide distribution. Coxiella burnetii is the causative agent of Q fever in humans and coxiellosis in animals. Since its discovery in 1935, it has been shown to infect a wide range of animal species including mammals, birds, reptiles, and arthropods. Coxiella burnetii infection is of public and veterinary health and economic concern due to its potential for rapid spread and highly infectious nature. Livestock are the primary source of C. burnetii infection in most Q fever outbreaks which occurs mainly through inhalation of contaminated particles. Aside from livestock, many cases of Q fever linked to exposure to wildlife. Changes in the dynamics of human-wildlife interactions may lead to an increased potential risk of interspecies transmission and contribute to the emergence/re-emergence of Q fever. Although C. burnetii transmission is mainly airborne, ticks may act as vectors and play an important role in the natural cycle of transmission of coxiellosis among wild vertebrates and livestock. In this review, we aim to compile available information on vectors, domestic, and wild hosts of C. burnetii, and to highlight their potential role as bacterial reservoirs in the transmission of C. burnetii.

First serological record of Coxiella burnetii infection in the equine population of Slovakia

Coxiella burnetii is a worldwide zoonotic pathogen causing Q fever in various animal species and humans. In Slovakia, cases of C. burnetii infection in both animals and humans are confirmed every year. The role of horses in the epidemiology of this neglected disease is still unclear. In our study, we focused on a serosurvey of C. burnetii in the equine population in Slovakia by the ELISA method. Subsequently, a nested PCR was performed to detect the 16S rRNA fragment of the genus Coxiella. Among 184 horse sera, the presence of specific antibodies to C. burnetii was detected in four samples, representing a 2.17% seropositivity. All the positive horses were mares; two originated from Central Slovakia and two from Eastern Slovakia. Although the number of positive samples was too small for a determination of statistical significance, our results provide the first confirmation of antibodies to C. burnetii in horses from Slovakia. Although no positive PCR result was obtained, these serological findings may help to clarify the circulation of the pathogen in the environment.

Ticks and their epidemiological role in Slovakia: from the past till present

In Slovakia, 22 tick species have been found to occur to date. Among them, Ixodes ricinus, Dermacentor reticulatus, D. marginatus and marginally Haemaphysalis concinna, H. inermis and H. punctata have been identified as the species of public health relevance. Ticks in Slovakia were found to harbour and transmit zoonotic and/or potentially zoonotic agents such as tick-borne encephalitis virus (TBEV), spirochaetes of the Borrelia burgdorferi sensu lato (s.l.) complex, the relapsing fever sprirochaete Borrelia miyamotoi, bacteria belonging to the orders Rickettsiales (Rickettsia spp., Anaplasma phagocytophilum, Neoehrlichia mikurensis), Legionellales (Coxiella burnetii), and Thiotrichales (Francisella tularensis), and Babesia spp. parasites (order Piroplasmida). Ixodes ricinus is the principal vector of the largest variety of microorganisms including viruses, bacteria and piroplasms. TBEV, B. burgdorferi s.l., rickettsiae of the spotted fever group, C. burnetii and F. tularensis have been found to cause serious diseases in humans, whereas B. miyamotoi, A. phagocytophilum, N. mikurensis, Babesia microti, and B. venatorum pose lower or potential risk to humans. Distribution of TBEV has a focal character. During the last few decades, new tick-borne encephalitis (TBE) foci and their spread to new areas have been registered and TBE incidence rates have increased. Moreover, Slovakia reports the highest rates of alimentary TBE infections among the European countries. Lyme borreliosis (LB) spirochaetes are spread throughout the distribution range of I. ricinus. Incidence rates of LB have shown a slightly increasing trend since 2010. Only a few sporadic cases of human rickettsiosis, anaplasmosis and babesiosis have been confirmed thus far in Slovakia. The latest large outbreaks of Q fever and tularaemia were recorded in 1993 and 1967, respectively. Since then, a few human cases of Q fever have been reported almost each year. Changes in the epidemiological characteristics and clinical forms of tularaemia have been observed during the last few decades. Global changes and development of modern molecular tools led to the discovery and identification of emerging or new tick-borne microorganisms and symbionts with unknown zoonotic potential. In this review, we provide a historical overview of research on ticks and tick-borne pathogens in Slovakia with the most important milestones and recent findings, and outline future directions in the investigation of ticks as ectoparasites and vectors of zoonotic agents and in the study of tick-borne diseases.

Spotted fever group rickettsiae in Dermacentor marginatus from wild boars in Italy

Following the increase in wild boar population recorded in urban and peri-urban areas throughout Europe, the present survey aimed to assess the occurrence of zoonotic tick-borne pathogens (TBPs) in wild boars living in southern Italy and in their ticks for evaluating the potential risk of infection for animals and humans. From October to December 2019, a total of 176 ticks collected from 93 wild boars andtheir spleen samples were molecularly screened for selected TBPs. Overall, all the wild boars were infested by ticks (mean intensity, 1.9) with Dermacentor marginatus and Ixodes ricinus being identified in 99.4% and 0.6%, respectively. Out of 93 wild boars, 17 (18.3%) were infested by ticks which scored positive to spotted fever group (SFG) Rickettsia species. Rickettsia slovaca and Rickettsia raoultii were identified in 16 (9%) and 1 (0.6%) D. marginatus, respectively, whereas a single I. ricinus (0.6%) was infected by R. slovaca. A single wild boar (1.1%) tested positive to R. slovaca. All ticks and wild boars scored negative to Babesia/Theileria spp., Ehrlichia spp., Anaplasma spp., Candidatus Neoehrlichia spp., Coxiella burnetii and Borrelia burgdorferi sensu lato complex. Data herein obtained suggest that wild boars are involved in the maintenance of D. marginatus in the environment as in peri-urban areas herein investigated. An integrated management approach is advocated for wild boar population control and in preventing the potential risk of TBPs infection in animals and humans.

Ticks, fleas and rodent-hosts analyzed for the presence of Borrelia miyamotoi in Slovakia: the first record of Borrelia miyamotoi in a Haemaphysalis inermis tick

In Slovakia, little knowledge is available on the occurrence, hosts and vectors of Borrelia miyamotoi of the relapsing fever group. In the current study, 2160 questing and rodent-attached ticks of six species (Ixodes ricinus, Ixodes trianguliceps, Dermacentor marginatus, Dermacentor reticulatus, Haemaphysalis concinna and Haemaphysalis inermis), 279 fleas belonging to 9 species (Ctenophthalmus agyrtes, Ctenophthalmus solutus, Ctenophthalmus assimilis, Megabothris turbidus, Amalareus penicilliger, Hystrichopsylla orientalis, Ctenophthalmus uncinatus, Doratopsylla dasycnema and Nosopsyllus fasciatus) and skin biopsies from 245 small mammals belonging to eight species (Apodemus agrarius, Apodemus flavicollis, Apodemus uralensis, Myodes glareolus, Crocidura leucodon, Micromys minutus, Microtus arvalis, Microtus subterraneus) were screened for the presence of B. miyamotoi DNA. The overall prevalence of B. miyamotoi found in questing and rodent-attached ticks was 1.8% (23 positive/1260 examined) and 3.4% (31 positive/900 examined), respectively. Borrelia miyamotoi was detected in questing I. ricinus, rodent-attached I. ricinus and H. inermis ticks, and in one male of the common vole (M. arvalis) in different habitats (mainly rural) in eastern Slovakia. However, B. miyamotoi was not found in any of the tested fleas. Our findings indicate that rural habitats with different species of tick vectors and hosts are appropriate for the occurrence of B. miyamotoi.

Coxiella burnetii in ticks and wild birds

The study objective was to get more information on C. burnetii prevalence in wild birds and ticks feeding on them, and the potentialities of the pathogen dissemination over Europe by both.

MATERIALS

Blood, blood sera, feces of wild birds and ticks removed from those birds or from vegetation were studied at two sites in Russia: the Curonian Spit (site KK), and the vicinity of St. Petersburg (site SPb), and at two sites in Bulgaria: the Atanasovsko Lake (site AL), and the vicinity of Sofia (site SR).

METHODS

C. burnetii DNA was detected in blood, feces, and ticks by PCR (polymerase chain reaction). All positive results were confirmed by Sanger's sequencing of 16SrRNA gene target fragments. The antibodies to C. burnetii in sera were detected by CFR (complement fixation reaction).

RESULTS

Eleven of 55 bird species captured at KK site hosted Ixodes ricinus. C. burnetii DNA was detected in three I. ricinus nymphs removed from one bird (Erithacus rubecula), and in adult ticks flagged from vegetation: 0.7% I. persulcatus (site SPb), 0.9% I. ricinus (site KK), 1.0% D. reticulatus (AL site). C. burnetii DNA was also detected in 1.4% of bird blood samples at SPb site, and in 0.5% of those at AL site. Antibodies to C. burnetii were found in 8.1% of bird sera (site SPb). C. burnetii DNA was revealed in feces of birds: 0.6% at AL site, and 13.7% at SR site.

CONCLUSIONS

Both molecular-genetic and immunological methods were applied to confirm the role of birds as a natural reservoir of C. burnetii. The places of wild bird stopover in Russia (Baltic region) and in Bulgaria (Atanasovsko Lake and Sofia region) proved to be natural foci of C. burnetii infection. Migratory birds are likely to act as efficient "vehicles" in dispersal of C. burnetii -infested ixodid ticks.

Diverse tick-borne microorganisms identified in free-living ungulates in Slovakia

BACKGROUND

Free-living ungulates are hosts of ixodid ticks and reservoirs of tick-borne microorganisms in central Europe and many regions around the world. Tissue samples and engorged ticks were obtained from roe deer, red deer, fallow deer, mouflon, and wild boar hunted in deciduous forests of south-western Slovakia. DNA isolated from these samples was screened for the presence of tick-borne microorganisms by PCR-based methods.

RESULTS

Ticks were found to infest all examined ungulate species. The principal infesting tick was Ixodes ricinus, identified on 90.4% of wildlife, and included all developmental stages. Larvae and nymphs of Haemaphysalis concinna were feeding on 9.6% of wildlife. Two specimens of Dermacentor reticulatus were also identified. Ungulates were positive for A. phagocytophilum and Theileria spp. Anaplasma phagocytophilum was found to infect 96.1% of cervids, 88.9% of mouflon, and 28.2% of wild boar, whereas Theileria spp. was detected only in cervids (94.6%). Importantly, a high rate of cervids (89%) showed mixed infections with both these microorganisms. In addition to A. phagocytophilum and Theileria spp., Rickettsia helvetica, R. monacensis, unidentified Rickettsia sp., Coxiella burnetii, "Candidatus Neoehrlichia mikurensis", Borrelia burgdorferi (s.l.) and Babesia venatorum were identified in engorged I. ricinus. Furthermore, A. phagocytophilum, Babesia spp. and Theileria spp. were detected in engorged H. concinna. Analysis of 16S rRNA and groEL gene sequences revealed the presence of five and two A. phagocytophilum variants, respectively, among which sequences identified in wild boar showed identity to the sequence of the causative agent of human granulocytic anaplasmosis (HGA). Phylogenetic analysis of Theileria 18S rRNA gene sequences amplified from cervids and engorged I. ricinus ticks segregated jointly with sequences of T. capreoli isolates into a moderately supported monophyletic clade.

CONCLUSIONS

The findings indicate that free-living ungulates are reservoirs for A. phagocytophilum and Theileria spp. and engorged ixodid ticks attached to ungulates are good sentinels for the presence of agents of public and veterinary concern. Further analyses of the A. phagocytophilum genetic variants and Theileria species and their associations with vector ticks and free-living ungulates are required.

Diversity of Coxiella-like and Francisella-like endosymbionts, and Rickettsia spp., Coxiella burnetii as pathogens in the tick populations of Slovakia, Central Europe

Ticks are important vectors of pathogens affecting humans and animals worldwide. They do not only carry pathogens but diverse commensal and symbiotic microorganisms are also present in ticks. A molecular screening for tick-borne pathogens and endosymbionts was carried out in Ixodes ricinus, Dermacentor reticulatus and Haemaphysalis inermis questing ticks collected in Slovakia. The presence of Rickettsia spp., Coxiella burnetii, Coxiella-like and Francisella-like microorganisms was evaluated by PCR in 605 individuals and by randomly sequencing 66 samples. Four species of rickettsiae (R. raoultii, R. slovaca, R. helvetica and R. monacensis) were identified and reported with an overall prevalence range between 0.4 and 50.3% (±8.0) depending on tick species, sex and locality. Partial sequencing of the gltA gene of 5 chosen samples in H. inermis showed 99% identity with Candidatus Rickettsia hungarica. The total prevalence of C. burnetii in ticks was 2.2 ± 1.7%; bacteria were confirmed in I. ricinus and D. reticulatus ticks. The sequences from 2 D. reticulatus males and 1 I. ricinus female ticks were compared to GenBank submissions and a 99.8% match was obtained with the pathogenic C. burnetii. Coxiella-like endosymbionts were registered in all three species of ticks from all studied sites with an average prevalence of 32.7 ± 3.7%. A phylogenetic analysis of this Coxiella sp. showed that it does not group with the pathogenic C. burnetii. The prevalence of Francisella-like microorganisms in questing ticks was 47.9 ± 3.9%, however H. inermis (n = 108) were not infested. Obtained sequences were 98% identical with previously identified Francisella-like endosymbionts in D. reticulatus and I. ricinus. Coxiella-like and Francisella-like microorganisms were identified for the first time in Slovakia, they might be considered as a non-pathogenic endosymbiont of I. ricinus, D. reticulatus and H. inermis, and future investigations could aim to assess their role in these ticks. However, this work provided further data and broadened our knowledge on bacterial pathogens and endosymbionts present in ticks in Slovakia to help understanding co-infestations, combined treatments and public health issues linked to tick bites.

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.

Molecular evidence of Rickettsia spp. in ixodid ticks and rodents in suburban, natural and rural habitats in Slovakia

BACKGROUND

Natural foci of tick-borne spotted fever group (SFG) rickettsiae of public health concern have been found in Slovakia, but the role of rodents in their circulation is unclear. Ticks (Ixodes ricinus, Ixodes trianguliceps, Dermacentor marginatus, Dermacentor reticulatus, Haemaphysalis concinna and Haemaphysalis inermis) and tissues of rodents (Apodemus flavicollis, Apodemus sylvaticus, Myodes glareolus, Microtus arvalis, Microtus subterraneus and Micromys minutus) were examined for the presence of SFG rickettsiae and Coxiella burnetii by molecular methods. Suburban, natural and rural habitats were monitored to acquire information on the role of ticks and rodents in the agents' maintenance in various habitat types of Slovakia.

RESULTS

The overall prevalence of rickettsial infection in questing I. ricinus and D. marginatus was 6.6% and 21.4%, respectively. Rickettsia helvetica, R. monacensis and non-identified rickettsial species were detected in I. ricinus, whereas R. slovaca and R. raoultii were identified in D. marginatus. Rickettsia spp.-infected I. ricinus occurred during the whole tick questing period. Rickettsia helvetica dominated (80.5%) followed by R. monacensis (6.5%). The species were present in all studied habitats. Rickettsia slovaca (66.7%) and R. raoultii (33.3%) were identified in D. marginatus from the rural habitat. Apodemus flavicollis was the most infested rodent species with I. ricinus, but My. glareolus carried the highest proportion of Rickettsia-positive I. ricinus larvae. Only 0.5% of rodents (A. flavicollis) and 5.2% of engorged I. ricinus removed from My. glareolus, A. flavicollis and M. arvalis were R. helvetica- and R. monacensis-positive. Coxiella burnetii was not detected in any of the tested samples. We hypothesize that rodents could play a role as carriers of infected ticks and contribute to the maintenance of rickettsial pathogens in natural foci.

CONCLUSIONS

Long-term presence of SFG Rickettsia spp. was confirmed in questing ticks from different habitat types of Slovakia. The results suggest a human risk for infection with the pathogenic R. helvetica, R. monacensis, R. slovaca and R. raoultii.

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.

Detection of Coxiella burnetii in ticks collected in Slovakia and Hungary

A total of 235 adult ticks collected from vegetation in Slovakia and Hungary in 1998-2000 were tested for Coxiella burnetii by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). C. burnetii was identified in six ticks of Ixodes ricinus, Dermacentor marginatus, and Haemaphysalis concinna species.

Host preferences of immature Dermacentor reticulatus (Acari: Ixodidae) in a forest habitat in Germany

Dermacentor reticulatus is widespread throughout Europe and is expanding its range in several European countries. It is associated with a number of different pathogens. Its role in the transmission of disease to humans is currently small; however, it might play an important role in the maintenance of pathogens in enzootic cycles. The ecology of D. reticulatus, especially of the immatures, is not well known. In this study, ticks from small mammals, caught in a capture-mark-release study between May 2012 and October 2014 in a unique woodland area close to Karlsruhe, Germany, were collected. The main host species trapped were the yellow-necked mouse (Apodemus flavicollis) and the bank vole (Myodes glareolus). Small mammal populations showed high variability in their density between the study years, which is probably due to harsh winter conditions in 2012/2013 and missing mast leading to high winter mortality. Larvae and nymphs of D. reticulatus were predominantly found in July and August, respectively, and the infestation rates among the different small mammal species suggest a host preference of D. reticulatus for M. glareolus.

Rickettsial infection in Ixodes ricinus ticks in urban and natural habitats of Slovakia

A total of 1810 Ixodes ricinus ticks was collected from the vegetation from 2 different habitat types: urban and natural. Urban habitats were represented by cemeteries and public parks in the following towns: Bratislava, Malacky, and Martin at 150 m and 400 m above sea level. Natural habitats were selected in the mountain forest of the Martinské hole Mts. in Central Slovakia at 3 different altitudinal levels, i.e. 600 m, 800 m and 1000 ma.s.l. All ticks were tested for the presence of spotted fever group rickettsiae. The DNA of Rickettsia spp. was identified in 9% of all tested ticks. Rickettsia-infected ticks were present in both, urban and sylvatic sites at all studied altitudes. Four different species of Rickettsia were present in positive I. ricinus ticks. Rickettsia helvetica was identified in 77 out of 87 Rickettsia-positive I. ricinus ticks, followed by 8 samples that belonged to Rickettsia monacensis and 2 of the positive ticks were infected with different unidentified Rickettsia spp. Due to the association of R. helvetica and R. monacensis with human infections, it is essential to understand which species of Rickettsia circulate in the natural foci of Slovakia. Circulation of pathogenic rickettsiae in urban as well as natural habitats at different altitudinal levels in Slovakia emphasizes that infection risk is very common throughout this Central European country.

Rickettsia slovaca and Rickettsia raoultii in Dermacentor marginatus and Dermacentor reticulatus ticks from Slovak Republic

Rickettsiae, obligate intracellular Gram-negative bacteria, responsible for mild to severe diseases in humans are associated with arthropod vectors. Dermacentor marginatus and Dermacentor reticulatus are known vectors of Rickettsia slovaca and Rickettsia raoultii distributed across Europe. A total of 794 D. marginatus, D. reticulatus and Ixodes ricinus adult ticks were collected from the vegetation, removed from horses, sheep, goats and dogs in Slovakia. The DNA of Rickettsia sp. was found in 229 ticks by PCR amplifying parts of gltA, ompA and sca4 genes. Next analyses of Rickettsia-positive samples by PCR-RFLP and/or sequencing showed D. reticulatus ticks were more infected with R. raoultii and D. marginatus were more infected with R. slovaca. The prevalence of R. raoultii was 8.1-8.6% and 22.3-27% in D. marginatus and D. reticulatus, respectively. The prevalence of R. slovaca was 20.6-24.3% in D. marginatus and 1.7-3.4% in D. reticulatus. Intracellular growth of R. raoultii isolate from D. marginatus tick was evaluated by rOmpA-based quantitative SybrGreen PCR assay. The highest point of multiplication was recorded on the 7th and 8th day postinfection in Vero and L929 cells, respectively. R. raoultii was transmitted during feeding of R. raoultii-positive ticks to guinea pigs and subsequently rickettsial infection was recorded in all organs, the highest infection was in spleen, liver and heart. Our study describes the detection and isolation of tick-borne pathogens R. raoultii and R. slovaca, show that they are spread in Slovakia and highlight their risk for humans.

Ixodid ticks of road-killed wildlife species in southern Italy: new tick-host associations and locality records

The present study aimed to identify ticks collected from road-killed wildlife species retrieved in several localities of southern Italy and to assess the presence of Borrelia burgdorferi sensu lato, Anaplasma phagocytophilum and Rickettsia spp. DNA in ticks. Collections were carried out from January 2000 to December 2009 on wild animals found dead within the territories of 11 municipalities from three regions (i.e., Apulia, Basilicata, and Calabria). In total, 189 carcasses of wild animals belonging to 10 species were checked for tick infestation, and 40 animals belonging to seven species were found parasitized. One hundred and twenty-five ixodid ticks (11 larvae, 14 nymphs, 77 males, and 23 females) were collected and identified as belonging to nine species, namely Dermacentor marginatus, Haemaphysalis erinacei, Hyalomma marginatum, Ixodes acuminatus, Ixodes canisuga, Ixodes hexagonus, Ixodes ricinus, Rhipicephalus bursa, and Rhipicephalus turanicus. None of the 36 tick specimens tested by PCR was positive for tick-borne pathogens. The results add new information on the tick fauna associated with wild animals in Italy, reporting new tick-host associations. Further field studies are still needed to ascertain the suitability of certain wildlife species as hosts for some tick species, particularly for those implicated in the transmission of pathogens to domestic animals and humans. Finally, from a conservation perspective, it would be interesting to assess whether these wild animals (e.g., Lepus corsicanus) are exposed to tick-borne pathogens, investigating the possible implications for their health and behavior.

The distribution and spreading pattern of Dermacentor reticulatus over its threshold area in the Czech Republic--how much is range of this vector expanding?

Host-seeking Dermacentor reticulatus ticks were detected by flagging method at 46 localities at south-east part of the Czech Republic, in the basins of rivers Morava and Dyje. Exact north-west distribution limits of D. reticulatus were defined in this area for the first time. Detailed prediction map of probabilities of D. reticulatus occurrence was obtained using GIS analysis. Spatial model delimited a south-north gradient in probability across the studied area, with highest probabilities above 0.8 in its southernmost part. Abundance of D. reticulatus varied markedly between localities in interval 0.33-222 of ticks per flag per hour. The highest abundances were in flooded areas at lower streams, towards upper streams abundance and density of these ticks decreased. Females prevailed in samples with population sex ratio of 0.413, significantly deviating from parity. Larvae and nymphs of this species were not detected by flagging. Although D. reticulatus range expansion probably did not reach such a degree as reported in other countries, these ticks became very abundant in some parts of studied area. Since spreading of vector-borne diseases became a problem in Europe, the knowledge of their exact recent geographic ranges is important for future modelling of their shift predictability.

Coxiella burnetii in humans and ticks in rural Senegal

BACKGROUND

Q fever is a worldwide zoonotic disease caused by Coxiella burnetii. Epidemiologically, animals are considered reservoirs and humans incidental hosts.

METHODOLOGY/PRINCIPAL FINDINGS

We investigated Q fever in rural Senegal. Human samples (e.g., sera, saliva, breast milk, feces) were screened in the generally healthy population of two villages of the Sine-Saloum region. Ticks were collected in four regions. Seroprevalence was studied by immunofluorescence, and all other samples were tested by two qPCR systems for detection of C. burnetii. Positive samples were genotyped (multispacer typing) by amplification and sequencing of three spacers. Strains were isolated by cell culture. We found that the seroprevalence may be as high as 24.5% (59 of 238 studied) in Dielmo village. We identified spontaneous excretion of C. burnetii by humans through faeces and milk. Hard and soft ticks (8 species) were infected in 0-37.6%. We identified three genotypes of C. burnetii. The previously identified genotype 6 was the most common in ticks in all studied regions and the only one found in human samples. Three strains of genotype 6 of C. burnetii were also recovered from soft tick Ornithodoros sonrai. Two other genotypes found in ticks, 35 and 36, were identified for the first time.

CONCLUSIONS/SIGNIFICANCE

Q fever should be considered a significant public health threat in Senegal. Humans, similar to other mammals, may continuously excrete C. burnetii.

Influence of biotope on the distribution and peak activity of questing ixodid ticks in Hungary

In order to update the occurrence of hard tick species in Hungary, 3442 questing ticks were collected from the vegetation by the dragging/flagging method in 37 different places in the country, between March and June of 2007. Ixodes ricinus (L.) turned out to be ubiquitous. Dermacentor marginatus (Schulzer) was absent from sampling sites in the southwestern part of the country, but in most places was concomitant and contemporaneous with Dermacentor reticulatus (Fabricius). These two species, as well as I. ricinus, occurred up to an altitude of 900-1000 m a.s.l. Haemaphysalis inermis (Birula) and Haemaphysalis concinna (Koch) were not confined to any parts of the country, unlike Haemaphysalis punctata (Canestrini & Fanzago) which was found in only one region. The local prevalence of the latter species was also significantly lower than those of the former two in the same habitat (fringes of meadows, paths in forests). Dermacentor spp. and H. inermis were represented only by adults. In most species females were collected more frequently than males, except in H. concinna and H. punctata. Temporal differences between the peak activity of I. ricinus and Dermacentor spp. on dry pastures appeared to equalize on meadows in mountain forests, and a similar phenomenon was observed for the three Haemaphysalis spp. when collected along forest paths with fresh, green vegetation.

Serologic evidence of Anaplasma phagocytophilum infections in patients with a history of tick bite in central Slovakia

The aim of this study was to determine the risks of human anaplasmosis in an area of central Slovakia endemic for Lyme borreliosis. The circulation of Anaplasma phagocytophilum in ticks and wild animals has been observed in natural foci in this area for several years. Samples of human sera from patients with Lyme borreliosis and persons with a history of recent tick bite and clinical symptoms indicating Lyme borreliosis were collected in central Slovakia. A total of 76 human sera were analyzed using an indirect HGE IgG immunofluorescent assay kit. IgG antibodies against A. phagocytophilum were found in 19 (25%) sera (15 female, 4 male patients). A. phagocytophilum infection was serologically confirmed in one (3.8%) child, 12 (38.7%) persons aged 22-56 and six (31.6%) persons older than 56. A statistically significant difference in seroprevalence (P < 0.01) was observed between children (3.8%, 1/26) and adults (36%, 18/50). Antibodies against A. phagocytophilum were detected in seven patients with clinically diagnosed Lyme borreliosis and in another seven individuals with assessed antiborrelia antibodies. IgG antibodies against A. phagocytophilum were detected in five persons seronegative for borrelia. The most frequent clinical symptoms in patients with positive A. phagocytophilum serology were cephalalgia, arthralgia, myalgia, fever, exanthema, neurological symptoms and lymphadenopathy. Positive sera were obtained from patients living in villages and towns in the orographic entities Vtácnik (5/19), Stiavnické vrchy (1/19), Kremnické vrchy (10/19) and Ziarska kotlina (3/19). Our results demonstrate the risk of acquiring A. phagocytophilum infection in natural foci in central Slovakia. Human anaplasmosis should be considered in the differential diagnosis, especially in cases of acute febrile illness with tick-bite history.

Ticks (Ixodidae) from passerine birds in the Carpathian region

Birds have been found to be a reservoir host of borrelia. In order to assess the situation in Slovakia ticks were collected from a total of 3057 mist-netted, ringed and released passerine birds in two locations at 500 m (in 2001) and 1000 m (in 2003) above sea level in the Bukovské Vrchy Hills, part of the Carpathian region in the north-east of Slovakia. A total of 75 birds of 16 species were infested with subadult ticks of Ixodes ricinus species (prevalence of parasitization 5%). Sixty-two larvae from 31 birds of 9 species and 80 nymphs from 52 birds of 15 species were found. The highest intensity of parasitization was observed on blackbirds Turdus merula, song thrushes T. philomelos and dunnocks Prunella modularis. Six Ixodes ricinus adult ticks were found on humans working with birds, and one I. ricinus female tick on their dog. In ticks, the presence of Rickettsia sp., Coxiella burnetii, Borrelia burgdorferi sensu lato and members of the Anaplasmataceae and Piroplasmidae, were investigated by polymerase chain reaction, followed by sequence analysis. Rickettsia sp. was found in 1 nymph from the European robin Erithacus rubecula, in 3 adult ticks (1 male, 2 females) from humans and in the tick from the dog. The closely related Ehrlichia- like species "Schotti variant" was detected in 1 nymph from the song thrush. Borrelia afzelii was identified in 1 male and B. garinii in 1 female tick collected on humans. Ixodes ricinus was found to be the vector of a wide spectrum of tick-borne pathogens in a mountainous area of the Carpathians. Because of the low yield of ticks and pathogens the importance of birds as reservoir hosts is still poorly understood.

Q fever in Bulgaria and Slovakia

As a result of dramatic political and economic changes in the beginning of the 1990s, Q-fever epidemiology in Bulgaria has changed. The number of goats almost tripled; contact between goat owners (and their families) and goats, as well as goats and other animals, increased; consumption of raw goat milk and its products increased; and goats replaced cattle and sheep as the main source of human Coxiella burnetii infections. Hundreds of overt, serologically confirmed human cases of acute Q fever have occurred. Chronic forms of Q fever manifesting as endocarditis were also observed. In contrast, in Slovakia, Q fever does not pose a serious public health problem, and the chronic form of infection has not been found either in follow-ups of a Q-fever epidemic connected with goats imported from Bulgaria and other previous Q-fever outbreaks or in a serologic survey. Serologic diagnosis as well as control and prevention of Q fever are discussed.

Isolation of Coxiella burnetii and of an unknown rickettsial organism from Ixodes ricinus ticks collected in Austria

Two strains of Coxiella burnetii and two strains of an unidentified rickettsial organism were isolated for the first time from Ixodes ricinus ticks collected in the Alpine region of Tirol, Austria. The C. burnetii strains belong to the group of agents causing acute forms of Q fever. The other two strains of isolated rickettsial agent share some antigenic epitopes with C. burnetii and R. prowazekii but they differ from them by their high sensitivity to freezing and refreezing and by poor multiplication in yolk sacs of chick embryos. There is at present no evidence that these organisms cause human illness and no ecological information is available. We suggest they may be some new species of rickettsiae or rickettsia-like organisms.

Immunochemical and antigenic characterization of Coxiella burnetii strains isolated in Europe and Mongolia

SDS-PAGE, immunoblotting and serological methods such as microimmunofluorescence (MIF) test and ELISA were used to compare protein and lipopolysaccharide (LPS) profiles and antigenicity of 12 Coxiella burnetii strains isolated mostly from ticks in Europe and Mongolia with three reference C. burnetii strains originating from USA, namely Nine Mile from tick, Priscilla from goat placenta and S from human heart valve. Among strains from Europe and Mongolia, no significant differences in protein and LPS profiles were observed, irrespective of their origin, i.e. the country and source of isolation. The LPS profiles of these strains appeared to be more related to those of Nine Mile strain associated with acute Q fever, than to those of strains S and Priscilla associated with chronic Q fever. In immunoblots all strains isolated from Slovakia and Poland reacted more expressively with rabbit serum against Nine Mile than with serum against Priscilla strain. In the MIF test and ELISA there were no substantial differences in antibody-binding capacity between the reference and newly isolated C. burnetii strains, except for strain Priscilla reacting with homologous serum in lower antigenic concentration than other strains under study. However, in the MIF test much higher antigenic concentrations of each C. burnetii strain was required to detect antibodies in the Priscilla serum than in the Nine Mile, Luga and S sera.

Studies of the prevalence of Coxiella burnetii, the agent of Q fever, in the foothills of the southern Bavarian Forest, Germany

In studies carried out in 1991 in the foothills of the southern part of the Bavarian Forest, in the district of Freyung/Grafenau, ticks and small mammals were collected and examined for the presence of Coxiella (C.) burnetii and sera of small mammals and cattle investigated for antibodies against this rickettsia. A total of 1716 imagines and nymphs of Ixodes ricinus were collected by flagging and 892 larvae and nymphs of the same tick species removed from small mammals. In addition to 1095 serum samples from cattle, 326 specimens of nine species of small terrestrian mammals were examined. Neither in ticks nor in rodents, C. burnetii was detected, however, in 17 of 21 localities, seropositive cattle were found. Altogether, 12% of all 1095 heads of cattle tested were seropositive for C. burnetii antibodies. These serological results indicated a wide dissemination of C. burnetii in cattle of the region investigated, but there was no indication of a natural focus. As in other areas of Europe, an independent natural cycle of the agent involving cattle only is assumed to occur in this region.