Tick reservoirs for piroplasms in central and northern Italy

Molecular Detection and Genotyping of Theileria spp. in Deer (Cervidae) in Korea

Major clinical symptoms of Theileria infection include fever, anemia, anorexia, jaundice, and decreased milk production. Although several studies have been conducted on tick-borne pathogens, including Theileria in Korea, only a few have focused on Theileria infection in deer, including the Korean water deer. Blood samples from 160 deer were collected and subjected to DNA extraction and polymerase chain reaction (PCR). Next, PCR-positive samples were sequenced and analyzed by constructing a phylogenetic tree. The results showed that the overall infection rate of Theileria was 8.1% (13/160). Infection rates of 100% were observed in the northern and southern regions. However, the study's limitation was its small sample size, wherein five and one samples were analyzed from the northern and southern regions, respectively. The central region exhibited the lowest infection rate of 2.9% (4/140). Infection rates also differed based on seasons, with the highest (18.4%, 9/49) being observed in spring, followed by that in summer (8.9%, 4/45). However, no infection was observed during autumn and winter. A phylogenetic analysis indicated that the PCR-positive samples contained Theileria luwenshuni, which usually infects small ruminants, such as goats and sheep.

First Molecular Evidence of Babesia vogeli, Babesia vulpes, and Theileria ovis in Dogs from Kyrgyzstan

Tick-borne parasitic diseases cause mild to severe infections among vertebrate hosts, including dogs. Species in the genus Babesia are important tick-borne pathogens and have worldwide distributions. Although there are data on the prevalence and distribution of Babesia species among dogs around the world, there is no information available in Kyrgyzstan, according to a literature review. In this study, 337 dogs were screened by nested PCR for the presence of the 18S small subunit ribosomal RNA (18S SSU rRNA) gene of piroplasm species. Overall prevalence was 6.23% (21/337) for Babesia/Theileria spp. DNA sequencing of positively tested samples revealed that eighteen samples were infected with Babesia vogeli (B. vogeli) (5.34%), two samples with B. vulpes (0.59%), and one sample with Theileria ovis (T. ovis) (0.29%). The phylogenetic analyses and nucleotide sequences in contrast with those present in GenBank revealed that two nucleotide substitutions (594th and 627th) were found between B. vogeli isolates, including ours, indicating that the mutation is relatively rare. The sequences of other pathogens obtained in this study confirmed 100% nucleotide identity with B. vulpes and T. ovis sequences in GenBank. To the best of our knowledge, B. vogeli, B. vulpes, and T. ovis were detected for the first time in dogs from Kyrgyzstan, and it is thought that results will contribute to the understanding of the epidemiology of canine tick-borne pathogens in the country.

An Update of Evidence for Pathogen Transmission by Ticks of the Genus Hyalomma

Current and likely future changes in the geographic distribution of ticks belonging to the genus Hyalomma are of concern, as these ticks are believed to be vectors of many pathogens responsible for human and animal diseases. However, we have observed that for many pathogens there are no vector competence experiments, and that the level of evidence provided by the scientific literature is often not sufficient to validate the transmission of a specific pathogen by a specific Hyalomma species. We therefore carried out a bibliographical study to collate the validation evidence for the transmission of parasitic, viral, or bacterial pathogens by Hyalomma spp. ticks. Our results show that there are very few validated cases of pathogen transmission by Hyalomma tick species.

A Systematic Review of the Distribution of Tick-Borne Pathogens in Wild Animals and Their Ticks in the Mediterranean Rim between 2000 and 2021

Tick-borne pathogens (TBPs) can be divided into three groups: bacteria, parasites, and viruses. They are transmitted by a wide range of tick species and cause a variety of human, animal, and zoonotic diseases. A total of 148 publications were found on tick-borne pathogens in wild animals, reporting on 85 species of pathogens from 35 tick species and 17 wild animal hosts between 2000 and February 2021. The main TBPs reported were of bacterial origin, including Anaplasma spp. and Rickettsia spp. A total of 72.2% of the TBPs came from infected ticks collected from wild animals. The main tick genus positive for TBPs was Ixodes. This genus was mainly reported in Western Europe, which was the focus of most of the publications (66.9%). It was followed by the Hyalomma genus, which was mainly reported in other areas of the Mediterranean Rim. These TBPs and TBP-positive tick genera were reported to have come from a total of 17 wild animal hosts. The main hosts reported were game mammals such as red deer and wild boars, but small vertebrates such as birds and rodents were also found to be infected. Of the 148 publications, 12.8% investigated publications on Mediterranean islands, and 36.8% of all the TBPs were reported in seven tick genera and 11 wild animal hosts there. The main TBP-positive wild animals and tick genera reported on these islands were birds and Hyalomma spp. Despite the small percentage of publications focusing on ticks, they reveal the importance of islands when monitoring TBPs in wild animals. This is especially true for wild birds, which may disseminate their ticks and TBPs along their migration path.

Molecular Prevalence of Selected Tick-Borne Pathogens in Dermacentor reticulatus Collected in a Natural Park in Italy

Dermacentor reticulatus is one of the most important vectors of tick-borne pathogens (TBPs) in Europe causing diseases in animals and humans. A longitudinal study was planned, aimed to detect the molecular prevalence of tick-borne pathogens, i.e., Babesia spp. and the spotted fever group Rickettsiae, and its seasonal variation in D. reticulatus questing ticks to define the temporal infection risk. Ticks were collected monthly over a period of 15 months in a peri-urban park in Lombardy, Italy. DNA extraction and molecular analyses were performed. Statistical analysis was carried out. Out of 488, 53 (P = 10.9%) adult questing ticks were positive for Babesia DNA. A higher prevalence was revealed in male (32/241, P = 13.3%) than in female (21/247, P = 8.5%) ticks. Positive ticks were mostly collected in winter months (P = 13.3%) compared to early (P = 7.9) and late (P = 12.8) spring months. A similar percentage of positive ticks was evidenced in transects 1 and 3 (5.8% and 6.5%, respectively); instead, a significant higher prevalence was recorded in transect 2 (P = 16.0%). Obtained sequences confirmed a homology of 100% with B. canis sequences deposited in GenBank. No ticks tested positive for Rickettsia spp. DNA (0/488, P = 0%). The conspicuous circulation of B. canis infection in D. reticulatus adult questing ticks confirms their role in the epidemiology of canine babesiosis and requires preventive measures for dogs in this recreational area. Even if no tick was positive for the spotted fever group Rickettsia, its capacity as a vector of zoonotic pathogens should not be neglected.

Distribution of Tick-Borne Pathogens in Domestic Animals and Their Ticks in the Countries of the Mediterranean Basin between 2000 and 2021: A Systematic Review

Tick-borne pathogens (TBPs) include a wide range of bacteria, parasites and viruses that cause a large spectrum of animal, human and zoonotic tick-borne diseases (TBDs). The object of this review was to establish an inventory and an analysis of TBPs found in domestic animals in the countries of the Mediterranean Basin. This geographic area occupies a central position between several continents and is an area of movement for animals, humans and pathogens of interest and their vectors, which is important in terms of animal and human health. In this systematic review, we included a total of 271 publications produced between 2000–2021 concerning TBPs in domestic animals. Among this literature, we found a total of 90 pathogen species (known as TBPs) reported in the 20 countries of the area; these were detected in tick species from domestic animals and were also directly detected in domestic animals. In all, 31 tick species were recorded and 12 domestic animal species, the latter comprising nine livestock and three pet species. More than 50% of the publications were from Western Europe. Island data were extracted and assessed, as islands of the Mediterranean Basin were represented in 16% of the publications and 77.8% of the TBPs reported. Our results show the importance of islands in the monitoring of TBPs, despite the low percentage of publications.

Prevalence and genetic characterization of a Babesia microti-like species in the North American river otter (Lontra canadensis)

A 4.5-month-old, male, North American river otter (Lontra canadensis) from Athens-Clarke County, Georgia, USA being temporarily housed at a rehabilitation facility, presented with a three-day history of lethargy, anorexia, and severe anemia. Antemortem blood smears revealed intraerythrocytic piroplasms. Supportive care and antiparasitic treatments were initiated, but the animal died three days following presentation. Gross necropsy revealed yellow discoloration of all adipose tissue throughout the carcass and a mildly enlarged, diffusely yellow to pale orange liver. Microscopically, moderate, centrilobular hepatocellular degeneration and necrosis were observed, consistent with hypoxia secondary to apparent hemolytic anemia. Piroplasms were frequently observed in red blood cells in histologic sections. The nearly full-length 18S rRNA gene sequence (1588 bp) was identical to a previously described piroplasm from North American river otters from North Carolina. Phylogenetically, based on the 18S rRNA gene sequence, the otter Babesia sp. was in a sister group with a clade that included several strains of Babesia microti-like species including Babesia sp. from badgers (Meles meles), Babesia vulpes, and Babesia sp. from raccoons (Procyon lotor). To better understand the distribution and genetic variability of this Babesia species, otters from four states in the eastern U.S. and California were tested. Overall, 30 of 57 (53%) otters were positive for Babesia sp. None of four otters from California were positive, but prevalences in eastern states were generally high, 5/9 (55%) in Georgia, 7/14 (50%) in South Carolina, 10/17 (59%) in North Carolina, and 8/13 (62%) in Pennsylvania). Partial 18S rRNA gene sequences from all populations were identical to the clinical case sequence. No Babesia sensu stricto infections were detected. There were six unique COI sequences (937 bp) detected in 18 positive otters. The most common lineage (A) was detected in 12 of 18 (67%) samples from Georgia, North Carolina, South Carolina, and Pennsylvania. Lineage B was found in two otters and the remaining lineage types were found in single otters. These six lineages were 99-99.8% similar to each other and were < 88% similar to related parasites such as B. vulpes, B. microti-like species of raccoons, B. microti, and B. rodhaini. Phylogenetically, the Babesia sp. of otters grouped together in a well-supported clade separate from a sister group including B. vulpes from fox (Vulpes vulpes) and domestic dogs. In conclusion, this report demonstrates that this piroplasm is a potential pathogen of North American river otters and the parasite is widespread in otter populations in the eastern United States.

Molecular assessment of Theileria equi and Babesia caballi prevalence in horses and ticks on horses in southeastern France

Equine piroplasmosis (EP) is a tick-borne disease caused by Babesia caballi and Theileria equi that is potentially emerging in non-endemic countries. We conducted a descriptive study to investigate EP prevalence and spatial distribution in an endemic region: the Camargue and the Plain of La Crau in France. In spring 2015 and 2016, we carried out sampling at stables (total n = 46) with a history of horses presenting chronic fever or weight loss. Overall, we collected blood from 632 horses, which were also inspected for ticks; these horses had been housed in the target stables for at least 1 year. We obtained 585 ticks from these horses and described land use around the stables. Real-time PCR was employed to assess T. equi and B. caballi prevalence in the horses and in the ticks found on the horses. For the horses, T. equi and B. caballi prevalence was 68.6% and 6.3%, respectively. For the ticks found on the horses, prevalence was 28.8% for T. equi and 0.85% for B. caballi. The most common tick species were, in order of frequency, Rhipicephalus bursa, R. sanguineus sl., Hyalomma marginatum, Haemaphysalis punctata, and Dermacentor sp. Horses bearing Rhipicephalus ticks occurred in wetter zones, closer to agricultural areas, permanent crops, and ditches, as well as in drier zones, in the more northern countryside. Compared to horses bearing R. bursa, horses bearing R. sanguineus sl. more frequently occurred near the Rhone River. Prevalence of T. equi in the ticks was as follows: Hyalomma marginatum (43%), Dermacentor sp. (40%), R. bursa (33%), R. sanguineus sl. (19%), and Haemaphysalis punctata (17%). In contrast, B. caballi only occurred in Dermacentor sp. (20%) and R. bursa (1%).

Eco-epidemiology of equine piroplasmosis and its associated tick vectors in Europe: A systematic literature review and a meta-analysis of prevalence

When studying a vector-borne disease, an eco-epidemiological approach is vital for a comprehensive understanding of how the pathogen circulates amongst populations. Equine piroplasmosis (EP), a tick-borne disease caused by the protozoans Babesia caballi and Theileria equi, is endemic in the Mediterranean basin of Europe and causes both animal health and economic issues for the equine sector. With no vaccine available, defining the episystem of the disease can help to identify which components of the host-pathogen-vector-environment system to target to improve preventive measures. In this systematic literature review, we collected relevant data on the eco-epidemiology of EP in Europe. The 62 studies remaining after the selection procedure explored potential vectors, indicators of parasite circulation and putative risk factors of EP. Eight hard tick species were identified as potential vectors of one or both piroplasm species. Meta-analyses were then conducted on prevalence and seroprevalence data in equids in European countries, demonstrating an estimated seroprevalence of 30% and 8% and prevalence of 25% and 2% for T. equi and B. caballi, respectively. Finally, herd management practices and environmental risk factors analysed in studies showed no real consensus between studies, but revealed a general trend highlighting age and exposure to ticks as risk factors, and vaccination as a protective factor. Through this study, we point out that only a few studies have focused on disease management practices and even fewer have studied the effect of environmental parameters on equid infections. Further investigation in these areas is required to better characterize the eco-epidemiology of EP and risk factors associated with this disease.

Ticks on wild boar in the metropolitan area of Barcelona (Spain) are infected with spotted fever group rickettsiae

Tick-borne pathogens (TBPs) constitute an emerging public health concern favoured by multidimensional global changes. Amongst these, increase and spread of wild boar (Sus scrofa) populations are of special concern since this species can act as a reservoir of zoonotic pathogens and promote tick abundance. Thus, we aimed to make a first assessment of the risk by TBPs resulting from wild boar and ticks in the vicinity of a highly populated area. Between 2014 and 2016, we collected spleen samples and 2256 ticks from 261 wild boars (out of 438 inspected) in the metropolitan area of Barcelona (MAB; northeast Spain). We morphologically identified four tick species: Hyalomma lusitanicum (infestation prevalence: 33.6%), Dermacentor marginatus (26.9%), Rhipicephalus sanguineus sensu lato (18.9%) and R. bursa (0.2%). Ticks were pooled according to species and individual host. A total of 180 tick pools and 167 spleen samples were screened by real-time PCR and/or reverse line blot hybridization assay for Ehrlichia sp., Anaplasma sp., Babesia sp., Rickettsia sp., Borrelia burgdorferi sensu lato and Coxiella burnetii. Seventy-two out of the 180 tick pools were positive to Rickettsia spp. (minimum prevalence of 8.7%), including Rickettsia massiliae, R. slovaca and R. raoultii. We did not detect Rickettsia spp. in wild boar spleens nor other TBPs in ticks or wild boars. Since the ticks identified can bite humans, and the recorded spotted fever group (SFG) rickettsiae are zoonotic pathogens, there is a risk of SFG rickettsiae transmission for MAB inhabitants. Our results suggest a broader distribution of H. lusitanicum, competent vector for the Crimean-Congo haemorrhagic fever virus than previously known. Wild boar is not a Rickettsia spp. reservoir according to the spleen negative results. However, its abundance could favour tick life cycle and abundance, and its proximity to humans could promote the infection risk by Rickettsia spp.

Mitochondrial sequences of Rhipicephalus and Coxiella endosymbiont reveal evidence of lineages co-cladogenesis

Rhipicephalus ticks are competent vectors of several pathogens, such as Spotted Fever Group Rickettsiae (SFGR) and many Babesia species. Within this genus, different R. sanguineus s.l. lineages show an unequal vector competence and resistance regarding some pathogenic strains. Current literature supports that tick endosymbionts may play an essential role in the transmission ability of a vector. Indeed, the microbial community of Rhipicephalus seems to be dominated by Coxiella-like endosymbionts (CLE). Still, their co-evolutionary associations with the complicated phylogeny of Rhipicephalus lineages and their transmissible pathogens remain unclear. We performed a phylogenetic congruence analysis to address whether divergent R. sanguineus s.l. lineages had a different symbiont composition. For that, we applied a PCR based approach to screen part of the microbial community present in 279 Rhipicephalus ticks from the Iberian Peninsula and Africa. Our analyses detected several qPCR-positive signals for both SFGR and Babesia species, of which we suggest R. sanguineus-tropical lineage as a natural vector of Babesia vogeli and R. sanguineus-temperate lineage of SFGR. The acquisition of 190 CLE sequences allowed to evaluate co-phylogenetic associations between the tick and the symbiont. With this data, we observed a strong but incomplete co-cladogenesis between CLE strains and their Rhipicephalus tick lineages hosts.

Dermacentor marginatus and Dermacentor reticulatus, and Their Infection by SFG Rickettsiae and Francisella-Like Endosymbionts, in Mountain and Periurban Habitats of Northwestern Italy

We investigated the distribution of Dermacentor spp. and their infection by zoonotic bacteria causing SENLAT (scalp eschar neck lymphadenopathy) in Turin province, northwestern Italy. We collected ticks in a mountain and in a periurban park, from vegetation and different animal sources, and we sampled tissues from wild boar. Dermacentor marginatus (n = 121) was collected in both study areas, on vegetation, humans, and animals, while D. reticulatus (n = 13) was exclusively collected on wild boar from the periurban area. Rickettsia slovaca and Candidatus Rickettsia rioja infected 53.1% of the ticks, and R. slovaca was also identified in 11.3% of wild boar tissues. Bartonella spp. and Francisella tularensis were not detected, however, Francisella-like endosymbionts infected both tick species (9.2%). Our findings provide new insights on the current distribution of Dermacentor spp. and their infection with a spotted-fever group rickettsiae in the Alps region. Wild boar seem to play a major role in their eco-epidemiology and dispersion in the study area. Although further studies are needed to assess the burden of rickettsial diseases, our results highlight the risk of contracting SENLAT infection through Dermacentor spp. bites in the region.

A case of Babesia vulpes infection in a dog in Russia

A six-year old pit bull terrier, female, was presented to a veterinary clinic in Mocsow, Russia. The leading clinical signs were a decrease in the physical activity of the dog with weight loss despite normal appetite. The dog had never traveled to other regions, but there was a history of a fight with a dog from Serbia about two years before. A severe anemia and azotemia were revealed during the examination. The merozoites of small Babesia were detected in a blood smear, which were identified as Babesia vulpes by PCR. The treatment with imidocarb dipropionate and atovaquone in combination with azithromycin was started, but one week later the dog was euthanized because of a serious health condition and poor prognosis. Contact transmission due to bites might have been the cause of infection in this case.

Investigation of Ixodid ticks as vectors of Babesia caballi and Theileria equi (Protozoa: Apicomplexa) in central Italy

Babesia caballi and Theileria equi are widely recognized as causative agents of equine pirolasmosis (EP), an acute, sub-acute, and chronic disease of equines, with relevant economic impact on horse trade worldwide. Although several studies on EP prevalence from central Italy have been published, data on ticks responsible for its transmission are still lacking. In this study, we identified a potential competent vector, investigating main features of its ecology together with EP infection rates. A two-year sampling of questing ticks was carried out for the first time in Italy in an area known for high EP prevalence in horse sera, detecting the association between Rhipicephalus bursa and causative agents of EP. Most of the positive pools harbored a single infection (91.1%); mixed infections were also detected (8.9%). The infection rate for T. equi slightly decreased among years; B. caballi showed a lower, but increasing, infection rate. Tick phenology, climate variables, and peaks of EP prevalence indicated late May and second half of June as periods with the highest risk of new infections, especially during warm and dry days.

Serological detection and risk factors for equine piroplasmosis in the semiarid region of Pernambuco, Northeastern Brazil

Equine piroplasmosis, an economically important disease in horses, has so far not been reported in Pernambuco state, Brazil. This study aimed to evaluate the seroprevalence of anti-Babesia caballi and anti-Theileria equi antibodies based on the detection of these agents in equine blood and in ticks on horses in the municipality of Petrolina, Pernambuco, northeastern Brazil. Blood samples were drawn from 393 horses and sera were examined by ELISA. The presence of tick infestations was evaluated, and 101 ticks were subjected to DNA amplification for the detection of Babesia spp. by polymerase chain reaction (PCR). No parasites were detected in the blood smears. Anti-B. caballi and anti-T. equi antibodies were found in 27.2% (107/393) and 34.8% (137/393) horses, respectively. Infestation by Dermacentor nitens was detected in 4.3% (17/393) of the horses. There was no DNA amplification of the agents in ticks. The risk factors for the presence of anti-T. equi antibodies (P < 0.05) were: purebred (P < 0.001), animals older than 156 months (P = 0.014), and the presence of ticks (P = 0.001). No risk factors for B. caballi were identified. This study confirmed the circulation of agents of equine piroplasmosis in the municipality of Petrolina, state of Pernambuco, Brazil.

First records of adult Hyalomma marginatum and H. rufipes ticks (Acari: Ixodidae) in Sweden

From July 2018 to January 2019 we recorded 41 specimens of adult Hyalomma ticks, which had been found on horses, cattle or humans in 14 Swedish provinces. In 20 cases we received tick specimens, which were identified morphologically as adults of H. marginatum (n = 11) or H. rufipes (n = 9). These are the first documented records in Sweden of adults of H. marginatum and H. rufipes. Molecular tests for Crimean-Congo haemorrhagic fever virus and piroplasms (Babesia spp. and Theileria spp.) proved negative; 12 out of 20 tested specimens were positive for rickettsiae (R. aeschlimannii was identified in 11 of the ticks). All ticks originated from people or animals that had not been abroad during the previous two months. These data suggest (i) that the adult Hyalomma ticks originated from immature ticks, which had been brought from the south by migratory birds arriving in Sweden during spring or early summer; and that (ii) due to the exceptionally warm summer of 2018 these immature ticks had been able to develop to the adult stage in the summer and/or autumn of the same year. The rapidly changing climate most likely now permits these two Hyalomma species to develop to the adult, reproductive stage in northern Europe. There is consequently a need to revise the risk maps on the potential geographic occurrence of relevant tick species and related tick-borne pathogens in Sweden and in the neighbouring countries.

Ixodid ticks on wild donkeys in a Mediterranean nature reserve (Asinara National Park): diversity and risk factors

The Sardinian coloured donkey Equus asinus (Perissodactyla: Equidae) and its albino colour morph represent the wildlife species most typical of the island of Asinara. This Mediterranean island represents a favourable context for ticks and tick-borne diseases; however, knowledge of the tick fauna on Asinara is scarce. A total of 106 Sardinian donkeys were inspected for tick infestation from June to November 2015. All ticks found were collected, classified by stage and sex, and identified to species level. The level of infestation of each donkey was determined; both the overall tick infestation and infestations of each detected species were classified on a scale of 1-3 to give an infestation score (IS). Overall, 256 hard ticks were collected from 60 of 106 donkeys (56.6%). Rhipicephalus bursa, Haemaphysalis punctata and Hyalomma marginatum (all: Ixodida: Ixodidae) infested 26.4%, 28.3% and 6.6% of donkeys, respectively. Different variables affected the IS. With reference to overall tick infestation, a higher IS was observed in donkeys grazing on grassland and Mediterranean shrubland and in albino donkeys compared with coloured donkeys. The collected ticks included species involved in the transmission of pathogens to humans, which highlights the risks for public health in a tourist destination such as Asinara National Park.

Establishment of Babesia vulpes n. sp. (Apicomplexa: Babesiidae), a piroplasmid species pathogenic for domestic dogs

BACKGROUND

Canine babesiosis is a severe disease caused by several Babesia spp. A number of names have been proposed for the canine-infecting piroplasmid pathogen initially named Theileria annae Zahler, Rinder, Schein & Gothe, 2000. It was shown to be a member of the Babesia (sensu lato) group infecting carnivores and is also closely related to the Babesia microti group. Subsequently, the same parasite species was reclassified as a member of the genus Babesia and the name Babesia vulpes Baneth, Florin-Christensen, Cardoso & Schnittger, 2015 was proposed for it. However, both names do not meet the requirements of the International Code of Zoological Nomenclature (no accompanying descriptions, no deposition of type-specimens) and cannot be recognized as available names from the nomenclatural point of view. The purpose of this study was to further characterize this parasite in order to confirm its validity, to provide its description and to introduce zoological nomenclature for it with the name Babesia vulpes n. sp.

RESULTS

Morphological description of the parasite in canine erythrocytes demonstrated that it takes the shape of small (1.33 × 0.98 µm), round to oval forms reminiscent of the pyriform and ring shapes of other small canine Babesia spp., such as Babesia gibsoni Patton, 1910 and Babesia conradae Kjemtrup, Wainwright, Miller, Penzhorn & Carreno, 2006. However, these parasite forms were overall smaller than those measured for the latter two species and no tetrad (Maltese cross) form was reported. Furthermore, phylogenetic analysis using the cytochrome c oxidase subunit 1 (COX1) amino acid sequences substantiates the species identity of this parasite as previously demonstrated based on phylogenetic analysis of the 18S rRNA and β-tubulin genes. The holotype of the parasite species was designated and deposited in an accessible public collection.

CONCLUSIONS

This study ratifies the name Babesia vulpes n. sp. proposed for the parasite previously referred to as Theileria annae Zahler, Rinder, Schein & Gothe, 2000, Babesia annae (Zahler, Rinder, Schein & Gothe, 2000) or Babesia vulpes Baneth, Florin-Christensen, Cardoso & Schnittger, 2015, or mentioned as "Babesia microti-like piroplasm", "Babesia Spanish dog isolate" and Babesia cf. microti.

The role of healthy dog carriers of Babesia microti-like piroplasms

BACKGROUND

While in Europe Babesia canis has been traditionally held responsible for canine piroplasmosis, Babesia microti-like piroplasm (Bml) infection is being ever more observed in dogs, with the first clinical cases reported in northwestern Spain. This study examines the epidemiological role of healthy dogs living in endemic areas of Bml infection in Spain. The data obtained were used to describe the clinical status and map the geographical distribution of Bml infection in healthy dogs in northwestern Spain.

RESULTS

Blood samples and ticks were taken from 756 healthy dogs representatively across the whole Galicia region (northwestern Spain): stray (n = 211), hunting dogs (n = 333) and pets (n = 212). Blood samples were tested by microscopy parasite observation, nested PCR-RFLP and sequencing. Piroplasm infection prevalences in healthy dogs from northwestern Spain were 17.1% (129/756) by PCR and 3.4% (26/756) by microscopy observation. The species found by PCR were: 2.2% (17/756) for B. canis and 15.1% (114/756) for Bml. Co-infection with B. canis and Bml was noted in 2 dogs. The higher prevalences detected were Bml in hunting dogs (25.5%; 85/333) and B. canis in stray dogs (6.6%; 14/211). In fox-hunting dogs from any area and dogs from the A Coruña Province, significantly higher prevalences of Bml infection were detected (P < 0.001). Upon physical examination, tick infestation was observed: 130 ticks in 18 hunting and three pet dogs. These were subsequently identified as Rhipicephalus sanguineus (s.l.) (49.2%), Ixodes hexagonus (38.5%), Ixodes ricinus (6.9%) and Dermacentor reticulatus (5.4%). Among the more prevalent ticks infesting healthy carrier dogs were I. hexagonus, followed by D. reticulatus and I. ricinus.

CONCLUSIONS

Babesia canis and Bml were the only piroplasm species found infecting healthy dogs in Galicia, the prevalence of Bml being higher than of B. canis. Factors correlated with a higher Bml infection risk were being a hunting dog and living in the A Coruña Province. Healthy dogs travelling to other countries could act as carriers and probably contribute to the spread of Bml infection in dogs and wild carnivores throughout Europe.

An annotated checklist of tick-borne pathogens of dogs in Nigeria

Tick-borne pathogens are transmitted by the bite of a tick vector or the ingestion therein by a susceptible host. Conventionally, the diagnosis of tick-borne parasites in Nigeria is achieved through the demonstration of their developmental stages in the host's blood or tissues. These classical methods are limited in their capability to detect chronic cases or healthy carriers and to differentiate between pathogens of similar morphological features. Molecular diagnostic techniques of high sensitivity have been developed to overcome these shortfalls by detecting the pathogen's DNA, elucidating their genetic makeup and comparing their phylogenetic relationship to other pathogens, sometimes necessitating taxonomic changes. Detection of DNA of canine tick-borne pathogens (CTBPs) such as Ehrlichia canis, Hepatozoon canis, and Mycoplasma haemocanis has been reported in Nigerian dogs corroborating earlier microscopic findings. Furthermore, DNA of Anaplasma platys, Ehrlichia ewingii, 'Candidatus Mycoplasma haemobos' and Theileria sp. hitherto considered to be absent in Nigeria has been detected, thereby expanding the spectrum of CTBPs in the country. However, in some cases, diagnoses based on the detection of single short DNA fragments from pathogens can cause considerable confusion. This occurred in the case of the large canine Babesia, previously referred to as Babesia canis which has been reported in Nigerian dogs. There appears to be confusion regarding the accurate status of this pathogen in Nigeria due to the subsequent classification into Babesia canis, Babesia vogeli and Babesia rossi. Moreover, several molecular studies failed to detect the DNA of Babesia gibsoni previously reported in Nigerian dogs by light microscope. These findings necessitate regular update of the list of CTBPs of veterinary and medical importance, in order to keep practitioners abreast with these changes. Herein, an annotated checklist of tick-borne pathogens of dogs in Nigeria, based on available data from both classical and molecular studies, with notes explaining any discrepancies between the methods and probable explanations thereof, is presented.

A comprehensive review on past, present and future aspects of canine theileriosis

Canine theileriosis is a notorious tick borne piroplasmid infection of wild and domestic canines. The causative agent has not yet been accurately classified. PCR studies revealed that causative agent resembles to Theileria genus and thus provisionally named as Theileria annae. The other Theileria species reported in canines is Theileria annulata, Theileria equi and unnamed Theileria specie. This emergent canine infection is considered to be endemic in most of the European countries. However in Asia this disease has not been reported till date. The vectors responsible for transmission of this disease have not been determined. It has been suggested that DNA of Theileria annae has been detected in hard tick Ixodes hexagonus in Northwestern Spain and several other tick species. Clinically canine theileriosis is characterized by severe weakness, fever, hemoglobinuria and anemia. Recently atovaquone or buparvaquone plus azithromycin therapy showed better clinical efficacy. This comprehensive review is intended to summarize the current knowledge on prevalence and epidemiology of canine theileriosis in different countries of the world and associated tick vectors.

Dermacentor reticulatus, a putative vector of Babesia cf. microti (syn. Theileria annae) piroplasm

Babesia cf. microti (syn. Theileria annae, Babesia microti-like, Babesia vulpes) is a recently recognized tick-borne piroplasm that infects domestic and wild carnivores. Although Ixodes hexagonus is considered as the leading candidate responsible for the transmission, its capacity to act as a competent vector has not yet been confirmed. This study reports the occurrence of B.cf. microti in unfed Dermacentor reticulatus for the first time, suggesting that this tick species may be implicated in the life cycle of this canine parasite. Out of 128 questing D. reticulatus ticks collected in eastern Austria, nine (7%) and four (3%) of them were found to be PCR positive for B. canis and B. cf. microti, respectively. Although the data presented here are not sufficient to explicitly state that D. reticulatus is a competent vector of B. cf. microti, our results can at least give a hint for future studies, which need to include experimental transmission in order to confirm its vector competence and possible involvement in the transmission of this babesial species.

Molecular evidence of tick-borne hemoprotozoan-parasites (Theileria ovis and Babesia ovis) and bacteria in ticks and blood from small ruminants in Northern Algeria

Using qPCR, standard PCR and/or sequencing, we investigated the presence of tick-associated microorganisms in ticks and blood from sheep and goats from Souk Ahras, Algeria. Borrelia theileri, was detected in (7/120, 5.8%) blood from sheep and (13/120, 10.8%) goats. Anaplasma ovis was screened in (38/73, 52%) Rhipicephalus bursa and (5/22, 22.7%) R. turanicus and in (74/120, 61.7%), (65/120, 54.2%) blood of sheep and goats respectively. Coxiella burnetii tested positive in R. bursa (4/73, 5.5%) and (7/120, 5.8%) blood of sheep and (2/120, 1.7%) goats. Theileria ovis was detected in (50/147, 34%) R. bursa and (3/22, 13.6%) R. turanicus and in (64/120, 53.3%) blood of sheep and (25/120, 20.8%) goats. Babesia ovis was screened positive in (23/147, 15.6%) R. bursa and (7/48, 14.6%) R. turanicus. Our findings expand knowledge about the repertoire of tick-borne microorganisms present in ectoparasites and/or the blood of small ruminants in Algeria.

Exposure to vector-borne pathogens in candidate blood donor and free-roaming dogs of northeast Italy

Background

Many vector-borne pathogens including viruses, bacteria, protozoa and nematodes occur in northeast Italy, representing a potential threat to animal and human populations. Little information is available on the circulation of the above vector-borne pathogens in dogs. This work aims to (i) assess exposure to and circulation of pathogens transmitted to dogs in northeast Italy by ticks, sandflies, and mosquitoes, and (ii) drive blood donor screening at the newly established canine blood bank of the Istituto Zooprofilattico Sperimentale delle Venezie.

Methods

Blood samples from 150 privately-owned canine candidate blood donors and 338 free-roaming dogs were screened by serology (IFA for Leishmania infantum, Ehrlichia canis, Anaplasma phagocythophilum, Babesia canis, Rickettsia conorii, R. rickettsii), microscopic blood smear examination, and blood filtration for Dirofilaria spp. All candidate donors and seropositive free-roaming dogs were tested by PCR for L. infantum, E. canis, A. phagocythophilum, Babesia/Theileria and Rickettsia spp. The dogs had no clinical signs at the time of sampling.

Results

Overall, 40 candidate donors (26.7 %) and 108 free-roaming dogs (32 %) were seroreactive to at least one vector-borne pathogen. Seroprevalence in candidate donors vs free-roaming dogs was: Leishmania infantum 6.7 vs 7.1 %; Anaplasma phagocytophilum 4.7 vs 3.3 %; Babesia canis 1.3 vs 2.7 %; Ehrlichia canis none vs 0.9 %; Rickettsia conorii 16 vs 21.3 % and R. rickettsii 11 vs 14.3 %. Seroreactivity to R. rickettsii, which is not reported in Italy, is likely a cross-reaction with other rickettsiae. Filariae, as Dirofilaria immitis (n = 19) and D. repens (n = 2), were identified in free-roaming dogs only. No significant differences were observed between candidate donors and free-roaming dogs either in the overall seroprevalence of vector-borne pathogens or for each individual pathogen. All PCRs and smears performed on blood were negative.

Conclusions

This study demonstrated that dogs are considerably exposed to vector-borne pathogens in northeast Italy. Although the dog owners reported regularly using ectoparasiticides against fleas and ticks, their dogs had similar exposure to vector-borne pathogens as free-roaming dogs. This prompts the need to improve owner education on the use of insecticidal and repellent compounds in order to reduce the risk of arthropod bites and exposure to vector-borne pathogens. Based on the absence of pathogens circulating in the blood of healthy dogs, the risk of transmission of these pathogens by blood transfusion seems to be low, depending also on the sensitivity of the tests used for screening.

The southernmost foci of Dermacentor reticulatus in Italy and associated Babesia canis infection in dogs

BACKGROUND

Two clustered clinical cases of canine babesiosis were diagnosed by veterinary practitioners in two areas of northeastern Italy close to natural parks. This study aimed to determine the seroprevalence of babesial infection in dogs, the etiological agents that cause canine babesiosis and the potential tick vector for the involved Babesia spp.

METHODS

The study area was represented by two parks in northeastern Italy: Groane Regional Park (Site A) and the Ticino Valley Lombard Park (Site B). From March to May 2015 ticks were collected from the vegetation in three transects in each site. In the same period, blood samples were collected from 80 dogs randomly chosen from veterinary clinics and kennel located in the two areas. Morphological identification of the ticks was performed and six specimens were molecularly characterised by the amplification and sequencing of partial mitochondrial 12S rRNA, 16S rRNA and cox1 genes. For phylogenetic analyses, sequences herein obtained for all genes and those available from GenBank for other Dermacentor spp. were included. Dog serum samples were analysed with a commercial indirect fluorescent antibody test to detect the presence of IgG antibodies against Babesia canis. Ticks and blood samples were tested by PCR amplification using primers targeting 18S rRNA gene of Babesia spp.

RESULTS

Ticks collected (n = 34) were morphologically identified as adults of D. reticulatus. Twenty-eight ticks were found in all transects from Site A and the remaining six were collected in Site B. Blast analysis of mitochondrial sequences confirmed the morphological identification of processed tick specimens by revealing a highest nucleotide similarity (99-100%) with those of D. reticulatus available in the GenBank database. The phylogenetic trees were concordant in clustering D. reticulatus in a monophyletic clade. Seven dogs (8.8%) had antibodies against B. canis, most of which (n = 6) came from Site A. Analysis of nucleotide sequences obtained from one tick and from one dog identified B. canis displayed a 100% similarity to those available in GenBank.

CONCLUSIONS

This study morphologically and molecularly confirms the presence of D. reticulatus in Italy and links it, for the first time, with the occurrence of B. canis infection in dogs in this country.

The ecological niche of Dermacentor marginatus in Germany

The ixodid tick Dermacentor marginatus (Sulzer, 1776) is endemic throughout southern Europe in the range of 33-51 (°) N latitude. In Germany, however, D. marginatus was exclusively reported in the Rhine valley and adjacent areas. Its northern distribution limit near Giessen is located at the coordinates 8.32 (°) E/50.65 (°) N. Particularly with regard to the causative agents of rickettsioses, tularemia, and Q fever, the observed locations as well as the potential distribution of the vector D. marginatus in Germany are of special interest. Applying a dataset of 118 georeferenced tick locations, the ecological niche for D. marginatus was calculated. It is described by six climate parameters based on temperature and relative humidity and another six environmental parameters including land cover classes and altitude. The final ecological niche is determined by the frequency distributions of these 12 parameters at the tick locations. Main parameters are the mean annual temperature (frequency distribution characterized by the minimum, median, and maximum of 6.1, 9.9, and 12.2 (°)C), the mean annual relative humidity (73.7, 76.7, and 80.9 %), as well as the altitude (87, 240, 1108 m). The climate and environmental niche is used to estimate the habitat suitability of D. marginatus in Germany by applying the BIOCLIM model. Finally, the potential spatial distribution of D. marginatus was calculated and mapped by determining an optimal threshold value of the suitability index, i.e., the maximum of sensitivity and specificity (Youden index). The model performance is expressed by AUC = 0.91.

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.

Pathogens vectored by the tick, Dermacentor reticulatus, in endemic regions and zones of expansion in Poland

Background

Dermacentor reticulatus plays an important role in the maintenance of pathogens of medical and veterinary importance in the environment. Currently two isolated populations of D. reticulatus are present in Poland –Western and Eastern. The range of the Eastern population covers endemic areas in eastern Poland but this population is expanding westwards creating an expansion zone in the centre of the country. The expansion zone in western Poland is occupied by the recently discovered Western population, spreading eastwards.

Methods

Questing adult ticks (n = 2585) were collected in 2012–2014 in endemic regions of north-eastern (Warmińsko-Mazurskie Voivodeship) and central Poland (Masovian Voivodeship) and in the expansion zones in central and western Poland, in the region between the Vistula River and the western border of the country. Amplification of Babesia, Rickettsia spp. and Borrelia burgdorferi sensu lato DNAs was performed using specific starters. RNA of the TBE virus was detected using RT-PCR and representative PCR products were sequenced and compared with sequences deposited in GenBank.

Results

Of the total 2585 examined ticks, 1197 (46.3 %) were infected with at least one pathogen. Overall prevalence of pathogens was 4.18 % (108/2585) for Babesia spp., 44.10 % (1140/2585) for Rickettsia spp., 0.09 % (1/1107) for Borrelia afzelii and 7.6 % (7/92) for TBEV. Sequence analysis of DNA showed 99.86 % similarity to R. raoulti and 99.81 % to B. canis. One male from north-eastern Poland was infected with B. microti.

Prevalence of R. raoulti was highest in the Western population (52.03 %) and lowest in the Eastern population in north-eastern Poland (34.18 %). Babesia canis was not detected in 592 ticks collected in the Western population, while in the Eastern population overall prevalence was 5.42 %. There were significant differences in the prevalence of B. canis between tick samples from northern (0.68 %), central (1.18 %) and southern (14.8 %) areas of the expansion zone in central Poland.

Conclusions

Our study found significant differences between the range and prevalence of vectored pathogens in D. reticulatus from the endemic areas and newly inhabited expansion zones. The differences were likely associated with the different time of settlement or ‘source’ of ticks populations, the Eastern and the Western one.

Update on epidemiology of canine babesiosis in Southern France

Background

Canine babesiosis is an emerging or re-emerging disease caused by Babesia and Theileria protozoans, also called piroplasms, transmitted by Ixodid ticks. In Europe, four etiological agents have been identified to date, namely Babesia canis, B. vogeli, B. gibsoni and Theileria annae. France has a high prevalence of canine babesiosis and two tick species, Dermacentor reticulatus and Rhipicephalus sanguineus, are supposed to transmit B. canis and B. vogeli respectively. In southern France, where dog infections with B. vogeli were recently confirmed, no comprehensive study was performed to date on piroplasm species infecting dogs. Thus, a large scale survey involving veterinary clinics, kennels and tick collection from the environment was conducted from 2010 to 2012 in this area.

Results

From 2010 to 2012, 140 dog blood samples and 667 ticks were collected. All blood and a subset of ticks were screened for the presence of piroplasms by PCR amplification of 18S rDNA. B. vogeli, B. canis and T. annae were detected in 13.6, 12.9 and 0.7 % dogs respectively. B. vogeli and B. canis were detected in 10.5 % and in 1.6 % R. sanguineus ticks including 1.3 % co-infections. B. canis was the only species detected in D. reticulatus ticks (9.7 %). B. canis infections were only recorded in the southwest of France whereas B. vogeli was mainly found in the southeast. Finally, a significantly higher prevalence of B. vogeli infection was found in Gard compared to Corsica and Drôme regions, both in dogs (p < 0.002) and R. sanguineus ticks (p < 0.02) although R. sanguineus was the main ticks species removed from dogs in those three areas.

Conclusions

The survey confirmed the circulation of both B. canis and B. vogeli in dogs in southern France with differences in distribution probably linked to the distribution of their respective vectors. It also showed differences in prevalence of B. vogeli infection in areas similar in terms of risk of dogs infestation with R. sanguineus. Further studies focusing on genetic and microbiota of R. sanguineus ticks should be conducted to explore other biological interactions that may explain the differences observed.

Molecular detection of Rickettsia, Borrelia, and Babesia species in Ixodes ricinus sampled in northeastern, central, and insular areas of Italy

The aim of the present study was to provide insight into the diversity of tick-borne pathogens circulating in Italy, carried/transmitted by Ixodes ricinus, one of the most abundant tick species in the country. A total of 447 specimens sampled in five areas of northeastern, central and insular Italy were analysed by polymerase chain reaction and sequencing for the presence of rickettsiae, borreliae and babesiae. Several rickettsial species of the spotted fever group of zoonotic concern and other zoonotic pathogens were found, such as Borrelia burgdorferi s.s., Borrelia afzelii, Borrelia garinii, and Babesia venatorum. These findings confirm a wide distribution of tick-borne bacterial and protozoan species in Italy, and highlight the sanitary importance of I. ricinus, often recorded as feeding on humans.

Reclassification of Theileria annae as Babesia vulpes sp. nov

Background

Theileria annae is a tick-transmitted small piroplasmid that infects dogs and foxes in North America and Europe. Due to disagreement on its placement in the Theileria or Babesia genera, several synonyms have been used for this parasite, including Babesia Spanish dog isolate, Babesia microti-like, Babesia (Theileria) annae, and Babesia cf. microti. Infections by this parasite cause anemia, thrombocytopenia, and azotemia in dogs but are mostly subclinical in red foxes (Vulpes vulpes). Furthermore, high infection rates have been detected among red fox populations in distant regions strongly suggesting that these canines act as the parasite’s natural host. This study aims to reassess and harmonize the phylogenetic placement and binomen of T. annae within the order Piroplasmida.

Methods

Four molecular phylogenetic trees were constructed using a maximum likelihood algorithm based on DNA alignments of: (i) near-complete 18S rRNA gene sequences (n = 76 and n = 93), (ii) near-complete and incomplete 18S rRNA gene sequences (n = 92), and (iii) tubulin-beta gene sequences (n = 32) from B. microti and B. microti-related parasites including those detected in dogs and foxes.

Results

All phylogenetic trees demonstrate that T. annae and its synonyms are not Theileria parasites but are most closely related with B. microti. The phylogenetic tree based on the 18S rRNA gene forms two separate branches with high bootstrap value, of which one branch corresponds to Babesia species infecting rodents, humans, and macaques, while the other corresponds to species exclusively infecting carnivores. Within the carnivore group, T. annae and its synonyms from distant regions segregate into a single clade with a highly significant bootstrap value corroborating their separate species identity.

Conclusion

Phylogenetic analysis clearly shows that T. annae and its synonyms do not pertain to Theileria and can be clearly defined as a separate species. Based on the facts that T. annae and its synonyms have not been shown to have a leukocyte stage, as expected in Theileria, do not infect humans and rodents as B. microti, and cluster phylogenetically as a separate species, this study proposes to name this parasite Babesia vulpes sp. nov., after its natural host, the red fox V. vulpes.

Electronic supplementary material

The online version of this article (doi:10.1186/s13071-015-0830-5) contains supplementary material, which is available to authorized users.

A molecular survey of vector-borne pathogens in red foxes (Vulpes vulpes) from Bosnia and Herzegovina

BACKGROUND

Red foxes (Vulpes vulpes) have recently been recognized as potential reservoirs of several vector-borne pathogens and a source of infection for domestic dogs and humans, mostly due to their close vicinity to urban areas and frequent exposure to different arthropod vectors. The aim of this study was to investigate the presence and distribution of Babesia spp., Hepatozoon canis, Anaplasma spp., Bartonella spp., 'Candidatus Neoehrlichia mikurensis', Ehrlichia canis, Rickettsia spp. and blood filaroid nematodes in free-ranging red foxes from Bosnia and Herzegovina.

METHODS

Spleen samples from a total of 119 red foxes, shot during the hunting season between October 2013 and April 2014 throughout Bosnia and Herzegovina, were examined for the presence of blood vector-borne pathogens by conventional PCRs and sequencing.

RESULTS

In the present study, three species of apicomplexan parasites were molecularly identified in 73 red foxes from the entire sample area, with an overall prevalence of 60.8%. The DNA of B. canis, B. cf. microti and H. canis was found in 1 (0.8%), 38 (31.9%) and 46 (38.6%) spleen samples, respectively. In 11 samples (9.2%) co-infections with B. cf. microti and H. canis were detected and one fox harboured all three parasites (0.8%). There were no statistically significant differences between geographical region, sex or age of the host in the infection prevalence of B. cf. microti, although females (52.9%; 18/34) were significantly more infected with H. canis than males (32.9%; 28/85). The presence of vector-borne bacteria and filaroid nematodes was not detected in our study.

CONCLUSION

This is the first report of B. canis, B. cf. microti and H. canis parasites in foxes from Bosnia and Herzegovina and the data presented here provide a first insight into the distribution of these pathogens among the red fox population. Moreover, the relatively high prevalence of B. cf. microti and H. canis reinforces the assumption that this wild canid species might be a possible reservoir and source of infection for domestic dogs.

First report on Babesia cf. microti infection of red foxes (Vulpes vulpes) from Hungary

Background

To date, only one report of a small Babesia infection based on microscopic observation which caused babesiosis in two dogs in Hungary has been published. Babesiosis due to Babesia canis - which is endemic in the local dogs - has only been detected in captive grey wolves. No information is available on babesial/theilerial infections in red foxes in Hungary. The aim of the study was to screen red foxes in Hungary for babesial parasites by PCR and to compare their partial 18S rRNA gene sequences to those parasites of domestic dogs and wild canids from other countries.

Methods

Blood samples of 404 red foxes originating from 316 locations representing all 19 Hungarian counties were screened in Hungary for babesial parasites by PCR and the partial 18S rRNA gene sequences were compared to those parasites of domestic dogs and wild canids from other countries.

Results

Altogether 81 red foxes out of 404 (20.0%; 95% CI: 16.4–24.2%) shot in 74 locations and in 17 of the 19 Hungarian counties were found to be infected with Babesia cf. microti by PCR.

Conclusions

This is the first report to demonstrate the occurrence of Babesia cf. microti in Hungary, and its widespread presence in the fox population throughout the country. Further studies are needed to identify the tick species involved in its transmission, and whether other mechanisms of transmission are involved in its spread in fox populations.

Vector ecology of equine piroplasmosis

Equine piroplasmosis is a disease of Equidae, including horses, donkeys, mules, and zebras, caused by either of two protozoan parasites, Theileria equi or Babesia caballi. These parasites are biologically transmitted between hosts via tick vectors, and although they have inherent differences they are categorized together because they cause similar pathology and have similar morphologies, life cycles, and vector relationships. To complete their life cycle, these parasites must undergo a complex series of developmental events, including sexual-stage development in their tick vectors. Consequently, ticks are the definitive hosts as well as vectors for these parasites, and the vector relationship is restricted to a few competent tick species. Because the vector relationship is critical to the epidemiology of these parasites, we highlight current knowledge of the vector ecology of these tick-borne equine pathogens, emphasizing tick transmissibility and potential control strategies to prevent their spread.

A molecular survey of Babesia spp. and Theileria spp. in red foxes (Vulpes vulpes) and their ticks from Thuringia, Germany

Wild canines which are closely related to dogs constitute a potential reservoir for haemoparasites by both hosting tick species that infest dogs and harbouring tick-transmitted canine haemoparasites. In this study, the prevalence of Babesia spp. and Theileria spp. was investigated in German red foxes (Vulpes vulpes) and their ticks. DNA extracts of 261 spleen samples and 1953 ticks included 4 tick species: Ixodes ricinus (n=870), I. canisuga (n=585), I. hexagonus (n=485), and Dermacentor reticulatus (n=13) were examined for the presence of Babesia/Theileria spp. by a conventional PCR targeting the 18S rRNA gene. One hundred twenty-one out of 261 foxes (46.4%) were PCR-positive. Out of them, 44 samples were sequenced, and all sequences had 100% similarity to Theileria annae. Similarly, sequencing was carried out for 65 out of 118 PCR-positive ticks. Theileria annae DNA was detected in 61.5% of the sequenced samples, Babesia microti DNA was found in 9.2%, and Babesia venatorum in 7.6% of the sequenced samples. The foxes were most positive in June and October, whereas the peak of tick positivity was in October. Furthermore, the positivity of the ticks was higher for I. canisuga in comparison to the other tick species and for nymphs in comparison to adults. The high prevalence of T. annae DNA in red foxes in this study suggests a reservoir function of those animals for T. annae. To our knowledge, this is the first report of T. annae in foxes from Germany as well as the first detection of T. annae and B. microti in the fox tick I. canisuga. Detection of DNA of T. annae and B. microti in three tick species collected from foxes adds new potential vectors for these two pathogens and suggests a potential role of the red fox in their natural endemic cycles.

Piroplasmosis in wildlife: Babesia and Theileria affecting free-ranging ungulates and carnivores in the Italian Alps

BACKGROUND

Piroplasmosis are among the most relevant diseases of domestic animals. Babesia is emerging as cause of tick-borne zoonosis worldwide and free-living animals are reservoir hosts of several zoonotic Babesia species. We investigated the epidemiology of Babesia spp. and Theileria spp. in wild ungulates and carnivores from Northern Italy to determine which of these apicomplexan species circulate in wildlife and their prevalence of infection.

METHODS

PCR amplification of the V4 hyper-variable region of the 18S rDNA of Babesia sp./Theileria sp was carried out on spleen samples of 1036 wild animals: Roe deer Capreolus capreolus (n = 462), Red deer Cervus elaphus (n = 52), Alpine Chamois Rupicapra rupicapra (n = 36), Fallow deer Dama dama (n = 17), Wild boar Sus scrofa (n = 257), Red fox Vulpes vulpes (n = 205) and Wolf Canis lupus (n = 7). Selected positive samples were sequenced to determine the species of amplified Babesia/Theileria DNA.

RESULTS

Babesia/Theileria DNA was found with a mean prevalence of 9.94% (IC95% 8.27-11.91). The only piroplasms found in carnivores was Theileria annae, which was detected in two foxes (0.98%; IC95% 0.27-3.49). Red deer showed the highest prevalence of infection (44.23%; IC95% 31.6-57.66), followed by Alpine chamois (22.22%; IC95% 11.71-38.08), Roe deer (12.55%; IC95% 9.84-15.89), and Wild boar (4.67%; IC95% 2.69-7.98). Genetic analysis identified Babesia capreoli as the most prevalent piroplasmid found in Alpine chamois, Roe deer and Red deer, followed by Babesia bigemina (found in Roe deer, Red deer and Wild boar), and the zoonotic Babesia venatorum (formerly Babesia sp. EU1) isolated from 2 Roe deer. Piroplasmids of the genus Theileria were identified in Wild boar and Red deer.

CONCLUSIONS

The present study offers novel insights into the role of wildlife in Babesia/Theileria epidemiology, as well as relevant information on genetic variability of piroplasmids infecting wild ungulates and carnivores.

Molecular and serological detection of Theileria equi and Babesia caballi infection in horses and ixodid ticks in Iran

Equine piroplasmosis is a hemoprotozoan tick-borne disease with worldwide distribution that is caused by Theileria equi and Babesia caballi. However, the geographical distribution of equine piroplasmosis in Iran is unknown. The aim of the current study was to determine the causative agents and vector ticks of equine piroplasmosis in horses in the North Khorasan Province. In the year 2011, 100 horses were randomly selected from 14 villages. Blood samples and ixodid ticks were collected and examined using microscopical, molecular, and serological methods. Theileria equi infection was microscopically detected in 5 (5%) of the blood smears with low parasitemia, while serum samples were tested by the indirect immunofluorescent antibody test (IFAT). Antibodies against T. equi, B. caballi, and a mixed infection were detected in 48 (48%), 2 (2%), and 3 (3%) of the serum samples, respectively. A multiplex PCR was used to detect T. equi and B. caballi DNA in blood samples. No B. caballi infections could be found, but Theileria equi DNA was detected in 45 (45%) of the blood samples, and a BLAST analysis of the sequenced samples indicated a 99% similarity with T. equi 18S rRNA gene sequences in GenBank. Both molecular and serological results did not identify any significant association between T. equi infection and risk factors. A comparision of the results of 3 diagnostic methods demonstrated a poor agreement between microscopical examination with IFAT and PCR and a moderate agreement between IFAT and PCR. Thirty-seven adult ticks (20 females and 17 males) were collected from 15 horses. The most common tick was Hyalomma marginatum marginatum (n=19), followed by Hyalomma anatolicum excavatum (n=10), Rhipicephalus bursa (n=4), Hyalomma marginatum turanicum (n=3), and Hyalomma anatolicum anatolicum (n=1). The salivary glands and ovaries were also examined using PCR. The genomic DNA samples of the salivary glands of 3 ticks, H. a. excavatum (n=2) and R. bursa (n=1), had a positive reaction for T. equi, but no tick contained B. caballi DNA. Thus, our results indicate that T. equi occurs more frequently than B. caballi in the investigated geographical region.

Coevolutionary analyses of the relationships between piroplasmids and their hard tick hosts

Host-parasite coevolution is a key driver of biological diversity. To examine the evolutionary relationships between piroplasmids and their hard tick hosts, we calculated the molecular clock and conducted phylogenetic analyses of both groups. Based on our results, we conclude that the divergence time of piroplasmids (∼56 Mya) is later than divergence time of their hard tick hosts (∼86 Mya). From analyses of the evolution of both piroplasmid and vector lineages and their association, we know that hard ticks transmit piroplasmids with high genus specificity and low species specificity.

Prevalence of Babesia microti-like infection in red foxes (Vulpes vulpes) from Portugal

The prevalence of piroplasm (order Piroplasmida) infection was assessed in blood and bone marrow samples from 91 red foxes (Vulpes vulpes) from northern, central and southern Portugal by means of molecular methods. PCR for the 18S rRNA gene of Babesia spp. followed by sequencing revealed 63 foxes positive for the Babesia microti-like piroplasm (syn. Theileria annae) (69.2%; 95% confidence interval [CI]: 58.7-78.5%) and one fox positive for Babesia canis (1.1%; 95% CI: 0.0-6.0%). Positivity to the B. microti-like piroplasm or B. canis in 43 blood samples (83.7%) was significantly higher (p<0.001) than in 43 paired bone marrow samples (20.9%). There were no statistically significant differences in the prevalence of infection between genders (p=0.219) or age groups (<2 years vs. ≥ 2 years) (p=1.0). This is the first report of the B. microti-like piroplasm in foxes from Portugal as well as the first report on detection by PCR and genotyping of B. canis in a red fox worldwide. A natural cycle of the B. microti-like piroplasm is suggested in red fox populations based on the high prevalence of the protozoan. Red foxes might be a reservoir of the B. microti-like piroplasm and a source of infection to dogs.

Wild cervids are host for tick vectors of babesia species with zoonotic capability in Belgium

Babesiosis is a tick-borne disease caused by different species of intraerythrocytic protozoan parasites within the genus Babesia. Different species of Babesia are described as potentially zoonotic and cause a malaria-like disease mainly in immunocompromised humans. Interest in the zoonotic potential of Babesia is growing and babesiosis has been described by some authors as an emergent zoonotic disease. The role of cervids to maintain tick populations and act as a reservoir host for some Babesia spp. with zoonotic capability is suspected. To investigate the range and infection rate of Babesia species, ticks were collected from wild cervids in southern Belgium during 2008. DNA extraction was performed for individual ticks, and each sample was evaluated for the absence of PCR inhibition using a PCR test. A Babesia spp. genus-specific PCR based on the 18S rRNA gene was applied to validated tick DNA extracts. A total of 1044 Ixodes ricinus ticks were collected and 1023 validated samples were subsequently screened for the presence of Babesia spp. DNA. Twenty-eight tick samples were found to be positive and identified after sequencing as containing DNA representing: Babesia divergens (3), B. divergens-like (5), Babesia sp. EU1 (11), Babesia sp. EU1-like (3), B. capreoli (2), or unknown Babesia sp. (4). This study confirms the presence of potentially zoonotic species and Babesia capreoli in Belgium, with a tick infection rate of 2.7% (95% CI 1.8,3.9%). Knowledge of the most common reservoir source for transmission of zoonotic Babesia spp. will be useful for models assessing the risk potential of this infection to 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.

Hard ticks (Ixodidae) in Romania: surveillance, host associations, and possible risks for tick-borne diseases

Ticks and tick-borne diseases represent a great concern worldwide. Despite this, in Romania the studies regarding this subject has just started, and the interest of medical personnel, researchers, and citizens is increasing. Because the geographical range of many tick-borne diseases started to extend as consequences of different biological and environmental factors, it is important to study the diversity of ticks species, especially correlated with host associations. A total number of 840 ticks were collected between 1 April and 1 November 2010, from 66 animals, from 17 species in 11 counties, spread all over Romania. Four Ixodidae species were identified: Dermacentor marginatus (49.2%), Ixodes ricinus (48.3%), Hyalomma marginatum (2.4%), and Rhipicephalus sanguineus (0.1%). The obtained results indicate that D. marginatus is the most abundant tick species and I. ricinus is the most prevalent. As both of them are important vectors for human and animal diseases, the present paper discusses the associated risks for tick-borne diseases.

Development of culture-based serological assays to diagnose Babesia divergens infections

Babesioses are hematic tick-borne diseases that induce malaria-like disorders in domestic, wild animals, and humans. Although indirect fluorescent antibody test (IFAT) and enzyme-linked immunosorbent assay (ELISA) commercial kits are available to test the presence of antibodies against most Babesia species, no kit exists to serologically diagnose the infections due to Babesia divergens, one of the most important zoonotic species. To fill this gap and to develop assays to detect animal and human infections, in vitro cultures (microaerophilous stationary phase system) of B. divergens were organized. Infected erythrocytes were adsorbed as corpuscular antigen (CA) on IFAT slides and ELISA microwells. The supernatant medium of the cultures (metabolic antigen, MA) was collected and employed in ELISA and western blot (WB) assays. B. divergens was also used to produce positive sera in Meriones unguiculatus and to infect a calf. Serological tests were set up with sera from experimentally/naturally infected animals, and possible cross-reactions were evaluated using heterologous sera from cattle positive to other piroplasms. Sera from clinically healthy people at risk of infection were also tested. As expected, assays based on the purified MAs from in vitro cultures proved more sensitive and specific than CA-IFAT and CA-ELISA. In fact, MA-ELISA provided satisfactory performances (even if 8.4%-15.7% cross-reactions were evidenced), and the WB developed proved totally sensitive and specific. WB indicated as immunodominant antigens two major protein bands at 33 and 37 kDa, which were also evidenced in 2.2% of the human sera tested, proving the parasite transmission to humans also in Italy.

New insights into the epidemiology of bovine piroplasmoses in Italy

Few studies have been published on bovine piroplasmoses in Italy, and therefore a clear picture of the epidemiology of these infections is difficult to obtain. Vertebrate and invertebrate hosts in Central and Northern Regions of Italy were investigated in 2005 and 2006, when microscopy, molecular tools and serological tests were applied to 468 blood samples drawn from cattle in order to evaluate the presence of these protozoa and identify possible risk factors. Ticks were also collected, identified and analyzed by molecular techniques. Microscopy identified 6.5% of the animals as positive, whereas PCR detected piroplasm DNA in 21.6%. BLAST analysis showed 67 amplicons (17.0%) referable to the Theileria sergenti/buffeli/orientalis group, 17 (4.3%) to Theileria annae, and 1 to Babesia divergens. Serology evidenced a prevalence of 45.4% for Babesia bovis, 17.4% for Babesia bigemina, and 34.9% for B. divergens. The 127 collected ticks were identified as belonging to 5 species, mostly represented by Rhipicephalus bursa, Hyalomma marginatum and Ixodes ricinus. Molecular analyses evidenced the presence of B. bovis and B. bigemina, in 3 and 5 ticks, respectively. Our findings suggest that different species of piroplasms are circulating in bovine populations in Central and Northern Italy, and provide new insights into the complex epidemiology of bovine piroplasmoses in Italy.