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

Large-scale molecular survey for piroplasmids in Iberian wild carnivores

Piroplasmids are vector-borne hemoprotozoan parasites belonging to the phylum Apicomplexa that are of veterinary and medical importance. Wild carnivores are hosts for diverse piroplasmids, some of which are highly pathogenic for domestic dogs and cats. A large-scale survey including samples from 244 individuals belonging to eleven different species that were opportunistically obtained between 1993 and 2015 in four Autonomous Regions in Spain were tested for piroplasmid DNA with two different nested-PCR assays targeting the 18S rRNA gene. Sixty of 85 Eurasian badgers (Meles meles), 11 of 42 red foxes (Vulpes vulpes), and 1 of 10 stone martens (Martes foina) resulted positive. In contrast, 46 wolves (Canis lupus), 26 genets (Genetta genetta), 22 pine martens (Martes martes), and other less-represented species were negative. Sequencing revealed that all foxes and one badger were parasitized by Babesia vulpes, and the remaining badgers and the stone marten by Babesia sp. badger type A (BBTA). The prevalence of BBTA in Catalonian badgers was significantly lower in Alpine than in Continental and Mediterranean climates. This study confirms that badgers and ref foxes constitute the natural hosts of BBTA and B. vulpes, respectively, with occasional spillovers to other species.

Short Communication: Anaplasma phagocytophilum and Babesia spp. in ixodid ticks infesting red foxes (Vulpes vulpes) in Great Britain

Red foxes (Vulpes vulpes) are found throughout the United Kingdom (UK), and can reach high population densities in urban areas. They are often infested with ticks which may carry tick-borne pathogens, leading to a risk of transmission to domestic animals and humans. This study investigated the prevalence of tick-borne pathogens in ticks sourced from red fox carcasses across Great Britain between 2018 and 2022. Tick species were identified using morphological keys and molecular barcoding, followed by specific pathogen testing using PCR. In total, 227 ticks were collected from 93 foxes. Pooling (n = 2) was undertaken for unengorged nymphs from the same tick species and fox host, with 203 homogenates tested in total (24 pools and 179 individual ticks). Ixodes hexagonus was the most abundant tick species sampled (73 %), of which 59 % were nymphs and 41 % were females. Less common were Ixodes ricinus (12 %) and Ixodes canisuga (15 %), the majority of which were females (73 % and 91 %, respectively). One Ixodes sp. larva was identified. Babesia DNA was identified in seven individual ticks and once in pooled ticks (n = 2); seven detections were in I. hexagonus and one in I. canisuga, with an overall detection rate of 7 % (95 % CI: 6 - 8 %). Sequence analysis confirmed that all Babesia detections in I. hexagonus were Babesia vulpes, with detection of Babesia Badger Type A in I. canisuga. Screening for Anaplasma phagocytophilum DNA through amplification of the msp2 gene yielded an overall detection rate of 4 % (detected in I. hexagonus only). Louping ill virus was not detected by qRT-PCR in any tick RNA tested. The majority of pathogen detections were in ticks from red foxes in rural areas of the UK, although a small number of Babesia detections were in ticks collected from semi-rural or urban red foxes. Additionally, B. vulpes was detected in GB red fox tissues, suggesting a potential role as a reservoir host. This study confirms the detection of tick-borne pathogens in ticks infesting UK red foxes and highlights the involvement of GB tick species in animal or human disease transmission.

Do Babesia microti Hosts Share a Blood Group System Gene Ortholog, Which Could Generate an Erythrocyte Antigen That Is Essential for Parasite Invasion?

The United States of America (US) has the highest annual number of human babesiosis cases caused by Babesia microti (Bm). Babesia, like malaria-causing Plasmodium, are protozoan parasites that live within red blood cells (RBCs). Both infectious diseases can be associated with hemolysis and organ damage, which can be fatal. Since babesiosis was made a nationally notifiable condition by the Centers for Disease Control and Prevention (CDC) in January 2011, human cases have increased, and drug-resistant strains have been identified. Both the Bm ligand(s) and RBC receptor(s) needed for invasion are unknown, partly because of the difficulty of developing a continuous in vitro culture system. Invasion pathways are relevant for therapies (e.g., RBC exchange) and vaccines. We hypothesize that there is at least one RBC surface antigen that is essential for Bm invasion and that all Bm hosts express this. Because most RBC surface antigens that impact Plasmodium invasion are in human blood group (hBG) systems, which are generated by 51 genes, they were the focus of this study. More than 600 animals with at least one hBG system gene ortholog were identified using the National Center for Biotechnology Information (NCBI) command-line tools. Google Scholar searches were performed to determine which of these animals are susceptible to Bm infection. The literature review revealed 28 Bm non-human hosts (NHH). For 5/51 (9.8%) hBG system genes (e.g., RhD), no NHH had orthologs. This means that RhD is unlikely to be an essential receptor for invasion. For 24/51 (47.1%) hBG system genes, NHH had 4-27 orthologs. For the ABO gene, 15/28 NHH had an ortholog, meaning that this gene is also unlikely to generate an RBC antigen, which is essential for Bm invasion. Our prior research showed that persons with blood type A, B, AB, O, RhD+, and RhD- can all be infected with Bm, supporting our current study's predictions. For 22/51 (43.1%) hBG system genes, orthologs were found in all 28 NHH. Nineteen (37.3%) of these genes encode RBC surface proteins, meaning they are good candidates for generating a receptor needed for Bm invasion. In vitro cultures of Bm, experimental Bm infection of transgenic mice (e.g., a CD44 KO strain), and analyses of Bm patients can reveal further clues as to which RBC antigens may be essential for invasion.

First molecular sequencing of Babesia gibsoni in ticks, Iraq

Background

Tick is one of the most important ectoparasites distributed worldwide and plays an obvious role in the transmission of different infections to humans and animals as dogs.

Aim

This study conducted to molecular demonstration of Babesia gibsoni in ticks of stray dogs and phylogenetic analysis of study isolates to detect their identity to global isolates. Prevalence of ticks in dogs, identification of tick species, and their relationship to some risk factors were aimed, also.

Methods

A total of 97 stray dogs were inspected grossly to detect and collect ticks that existed in different body parts. After collection, all ticks were examined morphologically to identify their species, and then molecularly by the polymerase chain reaction (PCR) assay to detect B. gibsoni in different species of ticks. Local B. gibsoni isolates were sequenced, documented in the National Center For biotechnology information (NCBI) database, analyzed phylogenetically, and compared with the global GenBank-NCBI isolates.

Results

In the current study, ticks were detected in 43.3% of dogs, and were shown to be varied in number and distribution among different body parts of each dog. Concerning its distribution, ticks were observed significantly on the abdomen, ear, and perineal region. In relation to risk factors, ticks were increased significantly in dogs <6 months old in comparison to older dogs, males more than females; and in rural areas more than dogs of sub-urban and urban areas. Based on morphology, different tick species were seen including Hylaomma anatolicum (86.12%), R. sanguineus (11.99%), and Rhipicephalus turanicus (1.89%). Targeting the 18S rRNA gene, PCR assay reported 3.79% positive ticks to B. gibsoni that were seen in R. sanguineus (13.16%) and H. anatolicum (2.56%). Based on phylogenetic analysis data of five local B. gibsoni isolates, this study demonstrated their close relations to the global NCBI-BLAST B. gibsoni Iraqi isolate (ID: MN385424.1).

Conclusion

This represents the first Iraqi study that demonstrated molecularly B. gibsoni in different species of ticks that infected stray dogs.

Diversity of Babesia spp. in skunks from selected states in the United States of America

Babesia species are intraerythrocytic protozoan parasites that infect a variety of hosts. The goal of this study was to evaluate the piroplasm species present in skunks in various states in the United States and determine whether there was any geographic variation. Spleen, whole blood, or blood on filter paper were received from Pennsylvania, Kentucky, North Carolina, South Carolina, Georgia, Missouri, Louisiana, Texas, Kansas, and California, and were tested for Babesia sp. We tested four species of skunks including striped skunk (Mephitis mephitis, n = 72), eastern spotted skunk (Spilogale putorius, n = 28), western spotted skunk (Spilogale gracilis, n = 15), and hog-nosed skunk (Conepatus leuconotus, n = 11). A PCR assay targeting the 18S rRNA region and cox1 region were used to determine if skunks were infected with piroplasms and for phylogenetic analyses. A total of 48.4% (61/126) of skunks tested positive for a Babesia species. Both the 18S and cox1 analysis supported a skunk-specific Babesia microti-like sp. of carnivores as well as a species in the B. microti complex that is phylogenetically unique from both B. microti of humans and the B. microti-like sp. of carnivores. In the 18S analysis, there was a third species of Babesia in hog-nosed skunks in the western piroplasm group. This study shows that at least three species of piroplasms occur in skunk species in the United States and further highlights the importance of phylogenetic analyses and the use of multiple gene targets when studying piroplasms.

Description and molecular characterisation of Babesia ailuropodae n. sp., a new piroplasmid species infecting giant pandas

BACKGROUND

Babesia spp. are protozoan parasites that infect the red blood cells of domesticated animals, wildlife and humans. A few cases of giant pandas (a flagship species in terms of wildlife conservation) infected with a putative novel Babesia sp. have been reported. However, comprehensive research on the morphological and molecular taxonomic classification of this novel Babesia sp. is still lacking. This study was designed to close this gap and formally describe this new Babesia sp. infecting giant pandas.

METHODS

Detailed morphological, molecular and phylogenetic analyses were conducted to characterise this Babesia sp. and to assess its systematic relationships with other Babesia spp. Blood samples from giant pandas infected with Babesia were subjected to microscopic examination. The 18S ribosomal RNA (18S rRNA), cytochrome b (cytb) and mitochondrial genome (mitogenome) of the new Babesia sp. were amplified, sequenced and assembled using DNA purified from blood samples taken from infected giant pandas. Based on the newly generated 18S rRNA, cytb and mitogenome sequences, phylogenetic trees were constructed.

RESULTS

Morphologically, the Babesia sp. from giant pandas exhibited various forms, including round to oval ring-shaped morphologies, resembling those found in other small canine Babesia spp. and displaying typical tetrads. Phylogenetic analyses with the 18S rRNA, cytb and mitogenome sequences revealed that the new Babesia sp. forms a monophyletic group, with a close phylogenetic relationship with the Babesia spp. that infect bears (Ursidae), raccoons (Procyonidae) and canids (Canidae). Notably, the mitogenome structure consisted of six ribosomal large subunit-coding genes (LSU1-6) and three protein-coding genes (cytb, cox3 and cox1) arranged linearly.

CONCLUSIONS

Based on coupled morphological and genetic analyses, we describe a novel species of the genus Babesia, namely, Babesia ailuropodae n. sp., which infects giant pandas.

Ticks analysis for molecular detection and phylogenetic evaluation of stray dogs infecting protozoa from Alborz, Iran

Ticks play an important role in the transmission of parasitic diseases, especially pathogenic protozoa in canine hosts, and it is very important to determine the role and extent of their infection with these pathogens in order to determine important control strategies. This study assessed the molecular prevalence of three protozoan pathogens including Hepatozoon canis, Leishmania spp. and Babesia spp., in ticks using PCR. A total 300 stray dogs were investigated and 691 ticks (171 male, 377 female and 143 nymph) were detected directly from 45 infested dogs. Species, stage of growth, and gender were determined for each tick. DNA extracted from 224 ticks (26 male, 165 female and 33 nymph). The molecular presence of three protozoan pathogens including Hepatozoon spp. (18S rRNA gene), Leishmania infantum (kinetoplastid minicircle DNA) and Babesia spp. (ssrRNA gene) were investigated using PCR method. One species of ticks, Rhipicephalus sanguineus was identified. Two of the target pathogens, Hepatozoon spp. (7/83; 8.43 %) and Babesia spp. (1/83; 1.2 %), were detected by PCR method. Sequence analysis of the ssrRNA gene of detected Babesia spp. showed a close relationship to the deposited strains of Babesia vulpis in the gene bank. To the best of our knowledge, this is the first study to undertake a phylogenetic analysis of H. canis and Babesia spp. in stray dogs in Alborz province, Iran and the first report about molecular detection of Babesia vulpis from tick infesting dogs in Iran. According to the above results, it seems necessary to implement tick control programs in dogs.

Analysis of Genetic Diversity of cytb gene from Babesia gibsoni Isolates from Naturally Infected Dogs in Karnataka, India

PURPOSE

The study aimed to investigate genetic diversity in Babesia gibsoni, the causative agent of canine babesiosis, and to assess the presence of atovaquone-resistant isolates in naturally infected dogs.

METHODS

A total of 24 blood samples confirmed for B. gibsoni infection was subjected to PCR amplification and sequencing based on cytb gene. Genetic characterization of B. gibsoni as well as attempts to detect the point mutation rendering atovaquone resistance was carried out based on the analysis of nucleotide sequence of cytb gene using bioinformatics software.

RESULTS

The findings indicated that the B. gibsoni isolates in the investigation exhibited a high nucleotide identity with the Asian genotype, ranging from 98.41 to 98.69%. Notably, none of the isolates carried cytb gene variants associated with atovaquone resistance. Phylogenetic analysis revealed clustering of most isolates with those from Japan and China, except for one isolate forming a distinct subclade. Haplotype network analysis indicated a high diversity with 22 distinct haplotypes among the B. gibsoni isolates, emphasizing the genetic variability within the studied population.

CONCLUSION

In conclusion, the cytb gene exhibited remarkable conservation among the twenty-four B. gibsoni isolates studied and the study represents the first genetic diversity assessment of B. gibsoni using the cytb gene in dogs from India. These findings shed light on the genetic characteristics of B. gibsoni in the region and provide valuable insight for addressing the challenges posed by this life-threatening disease in dogs.

Metabarcoding using nanopore long-read sequencing for the unbiased characterization of apicomplexan haemoparasites

Apicomplexan haemoparasites generate significant morbidity and mortality in humans and other animals, particularly in many low-to-middle income countries. Malaria caused by Plasmodium remains responsible for some of the highest numbers of annual deaths of any human pathogen, whilst piroplasmids, such as Babesia and Theileria can have immense negative economic effects through livestock loss. Diagnosing haemoparasites via traditional methods like microscopy is challenging due to low-level and transient parasitaemia. PCR-based diagnostics overcome these limitations by being both highly sensitive and specific, but they may be unable to accurately detect coinfections or identify novel species. In contrast, next-generation sequencing (NGS)-based methods can characterize all pathogens from a group of interest concurrently, although, the short-read platforms previously used have been limited in the taxonomic resolution achievable. Here, we used Oxford Nanopore Technologies' (ONT) long-read MinION™ sequencer to conduct apicomplexan haemoparasite metabarcoding via sequencing the near full-length 18S ribosomal RNA gene, demonstrating its ability to detect Babesia, Hepatozoon, Neospora, Plasmodium, Theileria and Toxoplasma species. This method was tested on blood-extracted DNA from 100 dogs and the results benchmarked against qPCR and Illumina-based metabarcoding. For two common haemoparasites, nanopore sequencing performed as well as qPCR (kappa agreement statistics > 0.98), whilst also detecting one pathogen, Hepatozoon felis, missed by the other techniques. The long-reads obtained by nanopore sequencing provide an improved species-level taxonomic resolution whilst the method's broad applicability mean it can be used to explore apicomplexan communities from diverse mammalian hosts, on a portable sequencer that easily permits adaptation to field use.

The Diverse Pathogenicity of Various Babesia Parasite Species That Infect Dogs

Babesia species infect a very wide range of mammal hosts across the globe, and zoonotic infections are of growing concern. Several species of the Babesia genus infect dogs, and some of these cause significant morbidity and mortality. The Apicomplexan parasite resides within the red cell and infections result in direct damage to the host through intra- and extravascular hemolysis. An exuberant inflammatory response by the host to some species of Babesia parasites also results in significant collateral damage to the host. Canine infections have been the subject of many studies as the well-being of these companion animals is increasingly threatened by the spread of tick vectors and an increasingly mobile dog population. There are currently no widely available and effective vaccines, and effective treatment can be challenging. Understanding disease pathogenesis underlies the development of new treatments. The varying pathogenicity of the various Babesia parasite species that infect dogs offers an opportunity to explore the molecular basis for the wide range of diseases caused by infection with this parasite genus. In this review, we focus on what has been reported about the clinical presentation of Babesia-infected dogs in an attempt to compare the severity of disease caused by different Babesia species.

First molecular detection of Babesia vulpes and Babesia capreoli in wild boars from southern Italy

Introduction

Following the increase of wild boar (Sus scrofa) populations in Europe, a potential risk of emerging infections by vector-borne pathogens may occur. Despite this, the circulation of piroplasmid species in these ungulates is still a neglected topic, particularly in the Mediterranean basin. Therefore, this study aimed to investigate the presence of Babesia/Theileria spp. in wild boars from southern Italy to assess the epidemiological role of these ungulates in the circulation of piroplasmids.

Methods

By using a citizen science approach among hunters and veterinarians, wild boar spleen samples were collected in the Campania region (southern Italy) between 2016 and 2022. A combined semi-nested PCR/sequencing analysis targeting the V4 hyper-variable region of 18S rRNA was run to detect Babesia/Theileria spp. DNA.

Results

Out of 243 boars, 15 (i.e., 6.2, 95% CI: 3.4-9.9) tested positive to Babesia/Theileria spp., Babesia vulpes (n = 13, 5.3, 95% CI: 3.1-8.9) the most prevalent, followed by Babesia capreoli (n = 2, 0.8, 95% CI: 0.2-2.9). Three different B. vulpes sequence types were identified (i.e., ST1, ST2, ST3), with the most representative as ST1 (60%), and a single B. capreoli sequence type. No statistically significant difference (p > 0.05) were found between the presence of the pathogens and boar age, sex, province and sample collection year.

Discussion

Data demonstrate for the first time the occurrence of B. vulpes and B. capreoli in wild boars, which may play a role in the biological cycle of piroplasmids. We emphasize the importance of monitoring these ungulates to prevent potential foci of infection. The engagement of hunters in epidemiological scientifically based surveys can constitute a technically sound control strategy of piroplasmids in a One Health perspective.

Canine piroplasmids: Molecular detection and laboratory characterization in dogs from Brasilia, Brazil, with the first molecular evidence of dog exposure to a novel opossum-associated Babesia sp

Canine piroplasmid infections can be caused by Babesia spp., Theileria spp. and Rangelia vitalii. In Brazil, canine babesiosis caused by Babesia vogeli is endemic and reported throughout the country. On the other hand, Rangeliosis caused by R. vitalii has only been described so far in the South and Southeast regions. Despite that, studies analyzing the laboratory and molecular characterization of these hemoprotozoa are still scarce. To investigate the occurrence, the laboratory features, the molecular characterization, and the diversity of piroplasmids from Midwestern Brazil, a survey was performed using blood samples obtained from 276 domestic dogs from Brasília, Federal District, Midwestern Brazil. A broad-range quantitative PCR (qPCR) targeting the mitochondrial large subunit ribosomal DNA (LSU4) was used to detect piroplasmid DNA. The overall molecular occurrence of piroplasmids was 11.2% (31/276), with 9.7% (27/276) of the sequences identified as Babesia vogeli (98-100% identity to B. vogeli isolate from the USA). Based on a partial 18S rRNA sequence pairwise alignment (-250 bp), 1.4% (4/276) of the sequences showed only 76.8% identity with B. vogeli but 100% identity with opossum-associated Babesia sp. (MW290046-53). These findings suggest the exposure of dogs from Brazil to a recently described Babesia sp. isolated from white-eared opossum. None of the analyzed dogs was positive for Theileria spp. or R. vitalii. Subsequently, all positive sequences were submitted to three additional PCR assays based on the 18S rRNA, cox-1, and cytb genes, aiming at performing a haplotype network analysis. Haplotype network using cox-1 sequences showed the presence of six different haplotypes of B. vogeli; one of them was shared with isolates from Brazil, the USA, and India. When including animals co-infected with other vector-borne diseases, piroplasmid-positive dogs had 2.3 times higher chance of having thrombocytopenia than the negative ones. The molecular results demonstrated that the compared Babesia vogeli sequences showed a low variability as well as evidence of exposure to a putative novel opossum-associated Babesia sp. in dogs from Midwestern Brazil.

Prevalence of Babesia and Ehrlichia in owned dogs with suspected tick-borne infection in Hong Kong, and risk factors associated with Babesia gibsoni

Babesiosis and ehrlichiosis are the most clinically significant tick-borne infections in dogs. Although epidemiological investigations of these diseases have been performed in some Asian regions, little data is available in Hong Kong, where competent vector tick species are endemic. The objectives of this study were to determine the molecular prevalence of Ehrlichia canis and Babesia species (B. canis, B. gibsoni, B. vogeli) in owned dogs suspected of tick-borne infection in Hong Kong and to identify risk factors associated with B. gibsoni infection. Electronic records from the Veterinary Diagnostic Laboratory of City University of Hong Kong were searched to identify canine blood samples submitted for molecular testing of these pathogens by real time PCR between March 2018 and May 2021. Electronic patient records from the affiliated veterinary hospital were searched to identify a subset of tested dogs to investigate the potential risk factors for B. gibsoni infection using logistic regression models. Among 1508 tested dogs for all four pathogens of interest, Babesia spp. were detected in 435 (28.8%) and E. canis in 112 (7.4%). Babesia gibsoni was detected in 408 dogs while B. vogeli was detected in 27 dogs. Babesia canis was not detected in any dog. Co-infections of different combinations of B. gibsoni, B. vogeli and E. canis were present in 25 dogs. In multivariable logistic regression, mixed breed dogs were more likely to be infected with B. gibsoni than purebreds (P = 0.005), while dogs > 10 years of age were less likely to be infected than younger dogs (P = 0.019). Hematological abnormalities significantly associated with B. gibsoni infection included thrombocytopenia, neutropenia, or pancytopenia. Babesiosis caused by B. gibsoni is a common infection in owned dogs suspected of tick-borne infection in Hong Kong. The risk factors reported should be considered in diagnosing dogs suspected of infection with this agent. Furthermore, consideration for testing for B. gibsoni infection should be given if the results of a complete blood count show thrombocytopenia even in the absence of anemia, neutropenia or pancytopenia.

Arthropod-Borne Pathogens in Wild Canids

Wild canids, as well as other wild animal species, are largely exposed to bites by ticks and other hematophagous vectors where the features favoring their presence and spread are found in wooded and semi-wooded areas. Much of the information about arthropod-borne infections concerns domestic and companion animals, whereas data about these infections in wild canids are not exhaustive. The present study is a narrative review of the literature concerning vector-borne infections in wild canids, highlighting their role in the epidemiology of arthropod-borne bacteria and protozoa.

Wild Mesocarnivores as Reservoirs of Endoparasites Causing Important Zoonoses and Emerging Bridging Infections across Europe

Mesocarnivores are small- or mid-sized carnivore species that display a variety of ecologies and behaviours. In Europe, wild mesocarnivores are represented by the red fox (Vulpes vulpes), the golden jackal (Canis aureus), the European wildcat (Felis silvestris), the Mustelidae of the genera Meles, Martes, Mustela, Lutra, the invasive species of raccoon dog (Nyctereutes procyonoides), raccoons (Procyon lotor), and American mink (Neogale vison). These abundant animals thrive in various habitats and often develop their activity close to human settlements. Thus, they may play an important role in the introduction, maintenance, and transmission of major parasitic zoonoses and promote bridging infections with domestic animals. Against this background, this article reports and discusses some of the most important endoparasites of wild mesocarnivores living in Europe, on the basis of their actual role as reservoirs, spreaders, or sentinels. The data derived from epizootiological studies in different European countries, and the proven or speculated implications of the detected endoparasites in human and domestic animals' health, are discussed. Through older and recent literature review, the state-of-the-art knowledge on the occurrence and prevalence of the parasites under consideration is presented, showing further, warranted investigations and the need for surveillance and vigilance.

Pathogenesis of Anemia in Canine Babesiosis: Possible Contribution of Pro-Inflammatory Cytokines and Chemokines-A Review

Canine babesiosis is a tick-borne protozoan disease caused by intraerythrocytic parasites of the genus Babesia. The infection may lead to anemia in infected dogs. However, anemia is not directly caused by the pathogen. The parasite's developmental stages only have a marginal role in contributing to a decreased red blood cell (RBC) count. The main cause of anemia in affected dogs is the immune response to the infection. This response includes antibody production, erythrophagocytosis, oxidative damage of RBCs, complement activation, and antibody-dependent cellular cytotoxicity. Moreover, both infected and uninfected erythrocytes are retained in the spleen and sequestered in micro-vessels. All these actions are driven by pro-inflammatory cytokines and chemokines, especially IFN-γ, TNF-α, IL-6, and IL-8. Additionally, imbalance between the actions of pro- and anti-inflammatory cytokines plays a role in patho-mechanisms leading to anemia in canine babesiosis. This article is a review of the studies on the pathogenesis of anemia in canine babesiosis and related diseases, such as bovine or murine babesiosis and human or murine malaria, and the role of pro-inflammatory cytokines and chemokines in the mechanisms leading to anemia in infected dogs.

Autochthonous Babesia canis infections in 49 dogs in Germany

BACKGROUND

Vector-borne diseases are of increasing importance in Germany. Since 2015, autochthonous cases have been increasingly documented in Berlin/Brandenburg.

OBJECTIVES

Describe autochthonous Babesia canis infection in the Berlin/Brandenburg region.

ANIMALS

Forty-nine dogs with autochthonous B. canis infection.

METHODS

Evaluation of history, clinical signs, laboratory abnormalities, treatment, and outcome.

RESULTS

Dogs were presented between March and August (9) and September and January (40) in the years 2015-2021. Historical and clinical findings were lethargy (100%), pale mucous membranes (63%), fever (50%), and pigmenturia (52%). Common clinicopathological findings were thrombocytopenia (100%), anemia (85%), intravascular hemolysis (52%), pancytopenia (41%), and systemic inflammatory response syndrome (SIRS; 37%). Babesia detection was based on blood smear evaluation (n = 40) and PCR targeting the 18S rRNA gene of piroplasms (n = 49). Sequencing indicated 99.47% to 100% identity to B. canis sequences from GenBank. All dogs were treated with imidocarb (2.4-6.3 mg/kg; median, 5 mg/kg); 8 dogs received 1, 35 received 2, and 1 dog each received 3, 4, or 5 injections, respectively. Continued PCR-positive results were detected in 7 dogs after the 1st, in 5 after the 2nd, in 2 after the 3rd, and in 1 28 days after the 4th injection. Four dogs were euthanized and 3 dogs died.

CONCLUSIONS AND CLINICAL IMPORTANCE

Autochthonous B. canis infections in Berlin/Brandenburg were associated with severe clinicopathological changes, SIRS, and multiorgan involvement. Testing by PCR during and after treatment is advisable to monitor treatment success. Screening of blood donors in high-risk areas and year-round tick protection is strongly recommended.

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

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

Red fox (Vulpes vulpes) play an important role in the propagation of tick-borne pathogens

The red fox (Vulpes vulpes) is the most widespread free-living carnivore in the world. Over the years, foxes have been recognized as hosts for a number of tick-borne pathogens. However, their role as reservoirs for zoonotic tick-borne diseases is poorly understood. The aim of our study was to investigate tick-borne pathogens in the red fox population in the Czech Republic. Out of 117 red foxes, 110 (94.02%) individuals tested positive for the presence of at least one pathogen by the combined PCR and sequencing approach. Hepatozoon canis was the most frequently detected pathogen (n = 95; 81.2%), followed by Babesia vulpes (n = 75; 64.1%). Babesia canis was not detected in our study. Four (3.42%) red foxes were positive for Candidatus Neoehrlichia sp., 3 (2.56%) for Anaplasma phagocytophilum, and one red fox (0.85%) tested positive for the presence of Ehrlichia sp. DNA. Overall, DNA of spirochetes from the Borrelia burgdorferi s.l. complex was detected in 8.6% of the foxes and B. miyamotoi in 5.12% of the samples. As a carnivore found in all ecosystems of Central Europe, foxes obviously contribute to transmission of tick-borne pathogens such as A. phagocytophilum, B. burgdorferi s.l., and B. myiamotoi. In addition, foxes apparently harbour a community of pathogens, associated with this host in local ecological context, dominated by H. canis and B. vulpes (possibly also Candidatus Neoehrlichia sp.). These species have the potential to spread to the domestic dog population and should be included in the differential diagnosis of febrile diseases with hematologic abnormalities in dogs.

Cross-sectional analysis of Piroplasma species-infecting camel (Camelus dromedaries) in Egypt using a multipronged molecular diagnostic approach

Camel piroplasmosis is a tick-borne disease (TBD) caused by hemoprotozoan parasites. Hereby, we describe a cross-sectional study aiming at identifying Piroplasma spp.-infecting camels in Egypt using a multipronged molecular diagnostic approach. A total of 531 blood samples from camels (Camelus dromedarius) were collected from slaughterhouses at different governorates in Egypt for analysis during the period from June 2018 to May 2019. Piroplasma spp. was identified using microscopical examination and several different and sequential polymerase chain reaction (PCR) assays targeting the 18S rRNA genes. The overall prevalence of Piroplasma spp. in microscopical and molecular analyses in the samples was 11% (58/531) and 38% (203/531), respectively. Further discriminative multiplex PCR analysis targeting the 18S rRNA gene applied on all Piroplasma spp.-positive samples allowed the detection of Theileria equi (41%), Babesia caballi (5.4%), Babesia bigemina (0.5%), and Babesia bovis (4%). Additionally, the blast analysis of nested (n) PCR, targeting the V4 region, amplicon sequences resulted in the identification of B. vulpes (22%), Babesia sp. (9%), and Theileria sp. (3%). Overall, the results of this study confirmed the high prevalence of TBDs caused by several types of piroplasm hemoparasites in camel and suggests the need for future interventions aimed at improving the control of these potentially debilitating diseases that may be t-hreatening important economic resources and food security in Egypt.

A novel promising diagnostic candidate selected by screening the transcriptome of Babesia gibsoni (Wuhan isolate) asexual stages in infected beagles

BACKGROUND

Babesia gibsoni is one of the causative agents of canine babesiosis worldwide. Some dogs infected with B. gibsoni show severe clinical signs with progressive anemia, hemoglobinuria and splenomegaly. However, most infected dogs present a state of chronic infection and thereby may be a persistent pathogen carrier, increasing the risk of pathogen spreading. To date, little is known about this pathogen, with genomic and transcriptomic data in particular generally unavailable. This lack of knowledge extensively limits the development of effective diagnostic strategies and vaccines.

METHODS

High-throughput RNA sequencing of total RNA of B. gibsoni asexual stages collected from infected beagles was performed. The unigenes were annotated in seven databases. The genes were sorted according to their fragments per kilobase per million (FPKM) value, which was used as an indicator for expression level. The gene with the highest FPKM value was cloned from the genome of B. gibsoni and further tested for immunogenicity, cellular localization and efficacy as a potential diagnostic candidate for detecting B. gibsoni in sera collected from beagles.

RESULTS

A total of 62,580,653 clean reads were screened from the 64,336,475 raw reads, and the corresponding 70,134 transcripts and 36,587 unigenes were obtained. The gene with the highest FPKM value was screened from the unigenes; its full length was 1276 bp, and it was named BgP30. The BgP30 gene comprised three exons and two introns, with a 786-bp open reading frame, and encoded 261 amino acids with a predicted molecular weight of 30 kDa. The cellular localization assay confirmed the existence of P30 protein in B. gibsoni parasites. Moreover, P30 was detected in the serum of experimentally B. gibsoni-infected beagles, from 15 days up to 422 days post-infection, suggesting its usefulness as a diagnostic candidate for both acute and chronic infections.

CONCLUSIONS

We sequenced the transcriptome of B. gibsoni asexual stages for the first time. The BgP30 gene was highly expressed in the transcriptome screening experiments, with further studies demonstrating that it could induce immune response in B. gibsoni-infected dogs. These results lead us to suggest that bgP30 may be a good diagnostic candidate marker to detect both acute and chronic B. gibsoni infections.

High genetic diversity of Babesia canis (Piana & Galli-Valerio, 1895) in a recent local outbreak in Berlin/ Brandenburg, Germany

Canine babesiosis caused by Babesia canis (Piana & Galli-Valerio, 1895) is emerging in new regions in Europe since its vector Dermacentor reticulatus (Fabricius, 1794) is expanding its geographic range. In the Berlin/Brandenburg area in northeast Germany, D. reticulatus is highly abundant but in the past only one autochthonous B. canis infection was reported. Since 2015, autochthonous cases were occasionally diagnosed but numbers increased since autumn 2019. The aim of the study was to genotype autochthonous canine Babesia spp. infections from Berlin/Brandenburg. Between 04/2015 and 01/2022, 46 dogs with acute babesiosis were presented to the small animal clinic (one dog was infected twice resulting in 47 samples). There were 32 dogs that had never left Berlin/Brandenburg and 14 others that had not left the region in the 6 weeks prior to disease onset. PCRs targeting the 18S rRNA and the Bc28.1 merozoite surface antigen were positive in 47 and 42 samples, respectively. Sequencing of cloned PCR products identified all samples as B. canis with 17 18S rRNA and 12 Bc28.1 haplotypes. Based on network analysis for 18S rRNA sequences and a previously described polymorphic dinucleotide, samples were assigned to two distinct clusters. One contained 31 and the other 16 samples. Using network analysis, the Bc28.1 haplotypes could also be separated into two clusters differing by at least five polymorphisms. Analyses of sequences from multiple clones indicated the presence of up to five 18S rRNA and eight Bc28.1 haplotypes and thus high parasite variability in an individual host. The genetic diversity could suggest that the parasites in the region have multiple origins, but diversity in individual dogs and dog populations from endemic regions is unknown. The suitability of both markers for genotyping is questionable due to potential intragenomic diversity for the rRNA and high intergenomic variability for the Bc28.1 marker.

[Occurrence of canine babesiosis in dogs in the Rhine-Main area of Hesse, Germany - a case study of 81 dogs]

OBJECTIVE

Canine babesiosis, an infectious disease transmitted by Dermacentor reticulatus, is exhibiting growing importance in Germany. The aim of this study was to display the increased incidence of canine babesiosis in the Rhine-Main area in Hesse, with special focus on the accumulation in the district of Groß-Gerau.

MATERIAL AND METHODS

The retrospective study included dogs presented to the veterinary hospital between October 2018 and December 2020 and diagnosed with canine babesiosis on the basis of a positive Babesia spp.-PCR.

RESULTS

A total of 697 dogs were tested by Babesia spp.-PCR during this time period. Of these, 81 (12 %) were positive.Sequencing was performed in 14 of the 81 dogs (17 %) (B. canis n = 13, B, vulpes n = 1). A simultaneous anaplasmosis infection was detected in 2 dogs. Strikingly, babesiosis cases occurred throughout the year with accumulations in March/April as well as in October.Evaluation of a complete blood cell count revealed pancytopenia in 44 of the 81 animals (54 %). Anemia was present in 66 (82 %), thrombocytopenia in 76 of the 81 patients (94 %). Only 2 of the 81 positive cases showed no hematological changes. Hyperbilirubinemia was found in 66 of 73 measured bilirubin levels (90 %).All animals were treated with two injections of imidocarb-diproprionate (Carbesia^®) in 14-day intervals. Follow-up PCR was performed in 37 of the 81 patients (46 %). In the majority of cases (92 %), successful therapy was confirmed by a negative Babesia-PCR. A total of 6 of the 81 patients (7 %) were euthanized during the treatment period. The reasons for euthanasia were progressive renal disease, high-grade intravascular hemolysis necessitating multiple blood transfusions, and development of splenic and renal abscesses.

CONCLUSION

In dogs with clinical signs such as apathy, pyrexia and hemoglobinuria, as well as hematologic abnormalities comprising anemia, thrombocytopenia as well as pancytopenia, babesiosis needs to be included in the list of differential diagnoses. Testing should be initiated accordingly regardless of the season, however especially in spring and autumn.

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.

Association between Increased the De Ritis Quotient and Renal Azotaemia in Canine Babesiosis

Simple Summary

This study investigated the association between increased serum aspartate aminotransferase (AST) activity and renal indices such as renal failure index, sodium fractional excretion, and urinary creatinine to serum creatinine ratio in dogs with renal azotaemia infected with Babesia canis. This research revealed that increased serum AST activity in azotaemic dogs may be of renal origin, and the de Ritis quotient may be a convenient and useful tool in the recognition of renal azotaemia in canine babesiosis.

Abstract

Previous studies of azotaemia in canine babesiosis revealed pre-renal and renal azotaemia in infected dogs, and an association between an increased de Ritis quotient (aspartate aminotransferase to alanine aminotransferase activity; AST/ALT ratio) and azotaemia in affected animals. Serum activities of AST and ALT, and AST/ALT ratio were compared between azotaemic and non-azotaemic dogs infected with Babesia canis, and between affected dogs with pre-renal and renal azotaemia. Statistical analyses revealed higher AST activity and an increased AST/ALT ratio in azotaemic dogs, and an increase of these two parameters in infected dogs with renal azotaemia in comparison to dogs with pre-renal azotaemia. Moreover, AST activity and AST/ALT ratio were correlated with renal indices such as renal failure index, sodium fractional excretion, and urinary creatinine to serum creatinine ratio. The study also revealed a lack of correlation between AST and ALT activities in azotaemic dogs, although a correlation was observed when including all dogs in this study (azotaemic and non-azotaemic dogs treated as one group). The results of this study indicate that increased serum AST activity in azotaemic dogs infected with B. canis may have a renal origin, and the AST/ALT ratio could be considered as a simple and convenient renal index that is useful in the recognition of renal azotaemia in canine babesiosis.

Microscopic Detection, Hematological Evaluation and Molecular Characterization of Piroplasms from Naturally Infected Dogs in Rio de Janeiro, Brazil

PURPOSE

This study aimed to analyze the frequency of piroplasmids in the blood of dogs in Rio de Janeiro, compare the performance of microscopic techniques, assess the risk factors associated with infections and also molecularly and morphologically characterize the piroplasmids identified.

METHODS

In all, 407 blood samples were collected from dogs between 2018 and 2019. These were subjected to microscopic parasitological techniques for thin and thick smears, stained with Giemsa and using a rapid staining kit. The slides were read under an optical microscope and the protozoa were characterized morphometrically. In addition, the blood samples were subjected to molecular characterization for diagnosing piroplasmid species using primers that amplified the gene 18S rRNA.

RESULTS

Piroplasmids were detected in 38 (9.3%) samples. Of these, 33 samples presented nucleotide sequences compatible with Babesia vogeli. Most of the positive samples were young, male, defined breeds dogs that had been attended in clinics in São Gonçalo city. Thrombocytopenia and leukopenia were the hematological alterations more observed in positive samples, but positive samples without alterations were also detected. The sex was the only variable that showed statistical differences. Males dogs being more often infected than females (p < 0.05). The microscope slides mostly showed piriform and oval merozoites measuring greater than 2.5 µm in length, which were compatible with B. vogeli. However, smaller forms were also identified, thus demonstrating the polymorphic nature of this parasite.

CONCLUSION

Babesia vogeli was detected in blood samples from dogs in the metropolitan cities of Rio de Janeiro by molecular techniques in different parasite morphotypes.

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

Background

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

Methods

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

Results

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

Conclusions

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

Graphical abstract

Supplementary Information

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

Patterns of Exposure and Infection with Microparasites in Iberian Wild Carnivores: A Review and Meta-Analysis

We use a suite of meta-analytic and comparative methods to derive fundamental insights into how sampling effort, pathogen richness, infection prevalence, and seroprevalence vary across Carnivora taxa and Iberian geography. The red fox was the most studied species, the wolf and Iberian lynx were disproportionally studied, and the Arctoidea were understudied. Sampling effort was higher in Mediterranean areas, but central Spain showed the higher pathogen richness. Excluding studies analyzing fecal samples, 53 different pathogens have been detected in Iberian carnivores, including 16 viruses, 27 bacteria, and 10 protozoa but no fungi. Sampling effort and pathogen diversity were generally more similar among closely related carnivore species. Seropositivity to viruses was lower and higher in the Mustelinae and the Canidae, respectively, and seropositivity to protozoa was higher in both taxa. Canine distemper virus exposure was greatest in canids and mustelids. Carnivore protoparvovirus-1 exposure was greatest in the Atlantic regions, and the Felidae and the Musteloidea had lower infection prevalence. A subclade of the Mustelidae had a greater prevalence of Leishmania infection. We observed no relationships between host phylogenetic distance and pathogen sharing among species. Lastly, we identify important research pitfalls and future directions to improve the study of infectious disease in Iberian wild carnivore communities.

What Babesia microti Is Now

Parasites from diverse hosts morphologically identified as Babesia microti have previously been shown to belong to a paraphyletic species complex. With a growing number of reports of B. microti-like parasites from across the world, this paper seeks to report on the current knowledge of the diversity of this species complex. Phylogenetic analysis of 18S rDNA sequences obtained from GenBank shows that the diversity of the B. microti species complex has markedly increased and now encompasses at least five distinct clades. This cryptic diversity calls into question much of our current knowledge of the life cycle of these parasites, as many biological studies were conducted before DNA sequencing technology was available. In many cases, it is uncertain which B. microti-like parasite was studied because parasites from different clades may occur sympatrically and even share the same host. Progress can only be made if future studies are conducted with careful attention to parasite identification and PCR primer specificity.

Babesia gibsoni infection in Italy: a cross sectional study of 607 blood samples belonging to dogs that needed a molecular analysis investigation (2016-2019)

Babesia gibsoni (B. gibsoni) infection was sporadically described in Europe. In Italy, in particular, it was detected by PCR analysis only in one dog with unclear source of infection, while it has never been found in molecular studies involving more subjects. The aim of this retrospective, cross-sectional study was to determine the presence and the proportion of B. gibsoni infected dogs in a convenient Italian canine population. Babesia spp PCR analysis reports of canine blood samples collected from January 2016 to December 2019 were selected from the San Marco veterinary laboratory database and evaluated. Piroplasms PCR analysis was performed on 18S rRNA gene and positive samples were sequenced. Available data about signalment, living area and season of diagnosis were evaluated and statistically analyzed. The studied canine population had a median age of 62 months (interquartile range, IQR: 72.5) and was composed of male/female purebred and mixed breed dogs. Through sequencing, B. canis (26/40, 65%), B. vogeli (7/40, 17.5%), B. gibsoni (6/40, 15%) and B. vulpes (1/40, 2.5%) infections were reported. The proportion of B. gibsoni infected dogs in the described population was of 0.99%. The infection resulted more likely in male (6/6, 100%), purebred (5/6, 83.3%) dogs with median age of 40.5 months (IQR:32.3). In one case, the clinical signs and parasitemia appeared after a dogfight with a cohabitant infected dog. No other plausible sources of infection were detected. Likely, this could be considered the first autochthonous B. gibsoni infection case documented in Italy. Our results underline the need of considering B. gibsoni not only an exotic, random and rare cause of disease for dogs in Italy, but a possible emerging pathogen to take into account during diagnostic and epidemiological investigations, in symptomatic as well as in asymptomatic patients.

Molecular epidemiology and prevalence of babesial infections in dogs in two hyperendemic foci in Brazil

Babesial parasites are some of the most ubiquitous blood pathogens and consequently have considerable worldwide veterinary impact. Dogs living in the tropics are highly exposed to babesial parasites, particularly to Babesia vogeli. Limited data on the seroprevalence and molecular prevalence of Babesia spp. in dogs are available in Latin America. We conducted a cross-sectional study combining serological and molecular tests to estimate the seroprevalence and molecular epidemiology of Babesia spp. infections in dogs in two hyperendemic foci in Brazil. A total of 630 privately owned dogs (417 from Goiana municipality, Pernambuco state, north-eastern Brazil, and 213 from São Joaquim de Bicas municipality, Minas Gerais state, south-eastern Brazil) were sampled and molecularly and serologically tested for Babesia spp. Overall, 519 dogs (82.4%) presented detectable IgG antibodies against Babesia spp., and seropositivity was significantly higher in dogs older than 1 year. Molecularly, 34 dogs (5.4%) were positive for a ~ 200 bp fragment of the 18S rRNA gene of Babesia spp. and 88 (14.0%) for a longer fragment (~ 450 bp) of the same gene of Babesia spp. and other protozoa. The 18S rRNA gene sequences generated herein corresponded to B. vogeli (n = 52) or Hepatozoon canis (n = 20). This study confirms a high level of exposure to B. vogeli in two areas of Brazil and highlights that most of the dogs living in these areas are infected during the course of their life, reflected by increased seroprevalence in older dogs. Increased awareness and prevention of tick-borne protozoa infections in dogs from Brazil and Latin America are urgently needed.

Molecular survey of vector-borne diseases in two groups of domestic dogs from Lisbon, Portugal

BACKGROUND

Canine vector-borne diseases (CVBDs) are caused by a wide range of pathogens transmitted by arthropods. They have been an issue of growing importance in recent years; however, there is limited information about the vector-borne pathogens circulating in Portugal. The aim of the present study was to detect canine vector-borne bacteria and protozoa of veterinary and zoonotic importance using molecular methods.

METHODS

One hundred and forty-two dogs from Lisbon, southern Portugal, were tested: 48 dogs from a veterinary hospital clinically suspected of vector-borne diseases and 94 apparently healthy dogs from shelters. Anaplasma spp./Ehrlichia spp., Babesia/Theileria spp., Hepatozoon spp., and Mycoplasma spp. infections were detected by PCR from blood samples and examined under light microscopy. Other information including clinical status and diagnostic test results were collected for each animal.

RESULTS

Infections were detected by PCR in 48 (33.80%) dogs. Single infections were found in 35 dogs (24.64%), and co-infections were found in 13 (9.15%) dogs. Twenty-nine (20.42%) dogs were positive for Hepatozoon spp., 15 (10.56%) for Mycoplasma spp., 11 (7.75%) for Anaplasma spp./Ehrlichia spp., and six (4.21%) for Babesia spp. DNA sequencing was used to identify Babesia vogeli (2.81%), Babesia canis (1.40%), Hepatozoon canis (20.42%), Mycoplasma haematoparvum (2.11%), Mycoplasma haemocanis (8.45%), Anaplasma platys (7.04%), and Ehrlichia canis (0.70%).

CONCLUSIONS

This is the first molecular identification of B. canis and M. haematoparvum in dogs from southern Portugal. This study highlights the importance of molecular methods to identify CVBD pathogens in endemic areas and helps to guide the clinical approach of veterinarians in practice.

Molecular survey on tick-borne pathogens and Leishmania infantum in red foxes (Vulpes vulpes) from southern Italy

Red foxes (Vulpes vulpes) have been recognised to harbour and transmit a wide range of tick-borne pathogens (TBPs) including those of zoonotic concern. To investigate the prevalence and the distribution of TBPs and of Leishmania infantum in foxes (n = 244), spleen samples were collected within the frame of a multi-regional wildlife health surveillance program in Italy. A combined PCR/sequencing approach was performed for the detection of Anaplasma spp., Babesia spp., Borrelia spp., Ehrlichia spp., Hepatozoon spp. and L. infantum DNA. Overall, 146 foxes (59.8 %, 95 % CI: 53.6-65.8) tested positive for at least one pathogen with Hepatozoon canis being the most prevalent (i.e., n = 124; 50.8 %, 95 % CI: 44.6-57.0), followed by Babesia vulpes (n = 20; 8.2 %, 95 % CI: 5.4-12.3), different spirochete species from Borrelia burgdorferi sensu lato complex (n = 9; 3.7 %, 95 % CI: 1.9-6.9), Ehrlichia canis and L. infantum (n = 7; 2.9 % each, 95 % CI: 1.4-5.8), Anaplasma platys (n = 4; 1.6 %, 95 % CI: 0.6-4.1), Anaplasma phagocytophilum ecotype I and Candidatus Neoehrlichia sp. (n = 3; 1.2 % each, 95 % CI: 0.4-3.5). All samples scored negative for Babesia canis and Borrelia miyamotoi. This study revealed the presence of spirochetes from B. burgdorferi s.l. complex, Ca. Neoehrlichia sp., A. platys and A. phagocytophilum ecotype I in red fox population from Italy, underling the necessity to monitoring these carnivores, mainly because they live in contact with dogs and humans. Data on the tick fauna circulating on wildlife species will complement information herein obtained, instrumentally to establish preventive strategies for minimizing the risk of infection for animals and humans.

Analysis of risk factors associated with recurrence of canine babesiosis caused by Babesia gibsoni

Canine babesiosis due to Babesia gibsoni (B. gibsoni) displays severe clinical manifestations. Recurrence of babesiosis after anti-babesial treatment is observable in over 10 % of the patients. The present study ascertains the risk factors and cumulative incidence of recurrence of canine babesiosis. For a sample of 145 dogs diagnosed with acute babesiosis, the following parameters were assessed over a period of 16 weeks: haematological parameters, status of anaemia, platelet count, total WBC count, haemoglobin concentration and RBC count, concurrent haemoparasitism, and secondary immune mediated haemolytic anaemia (IMHA). Patient demographics such as age, breed, sex were also recorded. The potential risk factors were statistically evaluated by the cumulative incidence function and the Kaplan-Meier method. The recurrent infections were observed in 11.8 % of the study sample. The following factors were found to associate with increased risk of recurrence: Rottweiler breed (CIR 21.8 % ± 6.9 %; p < 0.05), secondary IMHA (CIR 28.7 % ± 11.3 %; p < 0.05), RBC counts < 2 × 10⁶/μl on the day of diagnosis (CIR 16 % ± 4.6 %; p < 0.05), and persistent anaemia over 20 days post treatment (CIR 29.14 ± 7.9 %; p < 0.001). Dogs with concurrent haemoparasitic infections were predicted to have a fatal outcome in the survival analysis (disease related mortalities 25 % ± 13 %; p < 0.001). According to the findings, veterinarians need to pay attention to Rottweiler breed, dogs with secondary IMHA, concurrent haemoparasitism, low RBC counts on diagnosis and those with persistent anaemia to reduce the risk of relapse.

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.

Molecular detection and characterization of tick-borne hemoparasites and Anaplasmataceae in dogs in major cities of Malawi

Tick-borne pathogens (TBPs) in dogs have attracted much attention over the last decade since some are now known to be zoonotic and pose a threat to both animal and human health sectors. Despite the increase in the number of studies on canine TBPs worldwide, only a few studies have been conducted in resource-limited countries where research priority is given to food animals than companion animals. In the present study, the occurrence of TBPs of the genera Babesia, Hepatozoon, Anaplasma, and Ehrlichia was investigated in 209 owned and stray dogs in three major cities in Malawi through molecular techniques. Among the examined dogs, 93 (44.5%) were infected with at least one TBP. The detection rates were 23.1% for Babesia rossi, 2.9% for B. vogeli, 19.1% for Hepatozoon canis, 2.4% for Anaplasma platys, and 3.8% for Ehrlichia canis. This is the first molecular study that has provided evidence that dogs in Malawi are infected with TBPs. Sensitization is required for veterinary practitioners, dog handlers, and pet owners as the detected pathogens affect the animals' wellbeing. Further studies focusing on rural areas with limited or no access to veterinary care are required to ascertain the extent of the TBP infection in dogs.

Global distribution of canine Babesia species identified by a commercial diagnostic laboratory

Babesia species are important canine pathogens with a nearly worldwide distribution. Our understanding of the distribution of these parasites is continually improving. This is in large part, due to improved molecular diagnostic capabilities. However, it can be difficult to assimilate and compare previous reports from various regions due to differences in molecular methods. In this report, we characterize the results of over 100,000 canine samples from 52 different countries and territories spanning 4 continents that were submitted to a commercial diagnostic laboratory for Babesia testing by polymerase chain reaction. The same diagnostic algorithm was used for all samples and is designed to identify and differentiate B. gibsoni, B. canis, B. vogeli, B. rossi and B. conradae. Overall 3.4% of the samples submitted tested positive for the presence of Babesia sp. DNA and were differentiated to the species level. Babesia gibsoni was the most commonly identified species (48.8% of the positive results) followed by B. canis (35.2%) then B. vogeli (15.3%). Babesia gibsoni and B. vogeli were more widely distributed than B. canis, which was primarily found in Europe. This is the largest study of its type and these data provide a global overview of which Babesia species veterinarians could expect to find in their practice area.

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.

The red fox (Vulpes vulpes), a possible reservoir of Babesia vulpes, B. canis and Hepatozoon canis and its association with the tick Dermacentor reticulatus occurrence

The red fox (Vulpes vulpes) is known to be a reservoir host of various vector-borne protozoan parasites. Yet, the impact of these parasitic infections on the health status of the red fox is unknown. In this study, we compared the prevalence of haemoprotozoa in juvenile and adult foxes from four regions in Poland. The abundance of questing adult Dermacentor reticulatus ticks was shown to differ between regions and include a tick-endemic and non-endemic region, as well as two zones in which D. reticulatus recently expanded: an eastern and a western zone. Spleen and kidney enlargement indices were compared between infected, co-infected and non-infected foxes to evaluate pathogenic output of parasitic infections. Blood samples were collected from 383 necropsied red foxes and 25 live-trapped red fox cubs. The weights of spleens, kidneys and bodies were recorded for each necropsied individual. Blood and spleen DNA samples were screened by PCR to detect 18S rRNA and cox1 gene fragments of Babesia spp., and 18S rRNA of Hepatozoon spp. Prevalence of infection and mean organ weight indices were compared in relation to fox age and sex, origin (zone) and infection status. Hepatozoon canis (174/381; 45.7%) and Babesia vulpes (117/381; 30.7%) were the dominant pathogens infecting adult foxes. Babesia canis DNA was detected in 9 (2.4%) individuals. Two fox cubs from Western Poland were infected with B. vulpes (2/14; 14%), while H. canis infection (16/25; 59%) was detected in cubs from all three regions where trapping was carried out. Infection with B. vulpes was associated with significantly higher weights of spleens and kidneys. Spleen weight/ body weight and mean kidney weight/ body weight indices were shown as relevant in evaluating changes occurring during infection with B. vulpes. Babesia and Hepatozoon spp. infections differed in red foxes from D. reticulatus-endemic, non-endemic and newly inhabited areas. The prevalence of B. canis in foxes from four regions of Poland reflects the prevalence recorded in questing adult D. reticulatus collected in these areas. This finding suggests a contribution of red foxes to the establishment of new foci of B. canis-infected D. reticulatus ticks in areas recently invaded by this tick species. Spleen and kidney enlargement was identified in foxes infected with B. vulpes, particularly in individuals co-infected with B. vulpes and H. canis.

Molecular evidence of piroplasm infection in companion animals in Hunan Province, China

BACKGROUND

Feline and canine babesiosis is an important tick-borne disease caused by parasites of the genus Babesia. The disease has a worldwide distribution and causes serious health problems in domestic and wild canidae and felidae.

RESULTS

Genomic DNA was isolated from blood samples, which were randomly collected from pet dogs (n = 115) and cats (n = 25) in Changsha city of Hunan Province, China. Results of nested PCR assay targeting 18S rRNA gene and partial gene sequencing revealed that seven animals were infected with Babesia species, five dogs (5/115, 4.3%) and two cats (2/25, 8.0%). Sequence analysis showed that four dogs (3.5%) were positive for Babesia canis, and the other one for Babesia vogeli (0.87%). The two cats were infected by Babesia hongkongensis.

CONCLUSIONS

The findings of this study will expand knowledge of the distribution of Babesia species and provide important epidemiological information for the control of animal babesiosis in China.

A new piroplasmid species infecting dogs: morphological and molecular characterization and pathogeny of Babesia negevi n. sp

INTRODUCTION

Babesiosis is a protozoan tick-borne infection associated with anemia and life-threatening disease in humans, domestic and wildlife animals. Dogs are infected by at least six well-characterized Babesia spp. that cause clinical disease. Infection with a piroplasmid species was detected by light microscopy of stained blood smears from five sick dogs from Israel and prompted an investigation on the parasite's identity.

METHODS

Genetic characterization of the piroplasmid was performed by PCR amplification of the 18S rRNA and the cytochrome c oxidase subunit 1 (cox1) genes, DNA sequencing and phylogenetic analysis. Four of the dogs were co-infected with Borrelia persica (Dschunkowsky, 1913), a relapsing fever spirochete transmitted by the argasid tick Ornithodoros tholozani Laboulbène & Mégnin. Co-infection of dogs with B. persica raised the possibility of transmission by O. tholozani and therefore, a piroplasmid PCR survey of ticks from this species was performed.

RESULTS

The infected dogs presented with fever (4/5), anemia, thrombocytopenia (4/5) and icterus (3/5). Comparison of the 18S rRNA and cox1 piroplasmid gene sequences revealed 99-100% identity between sequences amplified from different dogs and ticks. Phylogenetic trees demonstrated a previously undescribed species of Babesia belonging to the western group of Babesia (sensu lato) and closely related to the human pathogen Babesia duncani Conrad, Kjemtrup, Carreno, Thomford, Wainwright, Eberhard, Quick, Telfrom & Herwalt, 2006 while more moderately related to Babesia conradae Kjemtrup, Wainwright, Miller, Penzhorn & Carreno, 2006 which infects dogs. The piroplasm forms detected included tetrads (Maltese cross), merozoite and trophozoite stages whose average size was larger than stages of other canine Babesia spp. belonging to the Babesia (s.l.) and B. gibsoni Patton, 1910, and smaller than other canine Babesia (sensu stricto) spp. Of 212 O. tholozani ticks surveyed, 11 (5.2%) harbored DNA of the new species of Babesia.

CONCLUSIONS

Babesia negevi n. sp. is described based on morphological and genetic characterization and phylogenetic analyses. The species is named after the Negev desert of southern Israel, where the first infected dog originated from. Despite co-infection in four dogs, the fifth dog had fatal disease attesting that B. negevi n. sp. infection requires clinical attention. Incriminating O. tholozani or another tick species as the vector of Babesia negevi n. sp., would require additional studies.

Don't let sleeping dogs lie: unravelling the identity and taxonomy of Babesia canis, Babesia rossi and Babesia vogeli

For most of the 20th century the causative agent of canine babesiosis, wherever it occurred in the world, was commonly referred to as Babesia canis. Early research, from the 1890s to the 1930s, had shown that there were three distinctly different vector-specific parasite entities occurring in specific geographical regions, that host response to infection ranged from subclinical to acute, and that immunity to one stock of the parasite did not necessarily protect against infection with other stocks. This substantial body of knowledge was overlooked or ignored for 50 years. In this review the first records and descriptions of the disease in four geographical regions were traced: sub-Saharan Africa, Europe, North Africa and Asia. Research leading to identification of the specific tick vector species involved is documented. Evidence is given of the growing realisation that there were substantial biological differences between stocks originating from different geographical regions. Etymological provenance for Babesia vogeli is proposed.

Babesia Species of Domestic Cats: Molecular Characterization Has Opened Pandora's Box

This is the first comprehensive review of the literature pertaining to Babesia species reported from domestic cats. Description of the four species (Babesia felis, Babesia cati, Babesia herpailuri, and Babesia pantherae) named based on morphology and/or host specificity is documented. Feline babesiosis is of major veterinary concern only in South Africa. Reports of the rare occurrence of feline babesiosis cases in Europe (France, Germany, Poland, and Spain) and Asia (Israel, India, and Pakistan) are documented. Molecular characterization has revealed that cats can harbor a variety of Babesia species. The previous practice of referring to all piroplasms, especially small ones, seen on feline blood smears as B. felis is therefore no longer tenable. The near-full-length 18S rRNA gene sequences entered into GenBank in 2001 (accession no. AF244912) are designated as definitive for B. felis sensu stricto. All published literature relating to molecular characterization of feline Babesia species that could be traced was critically assessed. Four Babesia species are now known to be involved in causing feline babesiosis in South Africa: the closely related B. felis s.s. and Babesia leo (clade I), Babesia lengau (clade II), and Babesia species cat Western Cape (clade VI, Babesia s.s.). Clade VI also includes Babesia canis presentii and Babesia hongkongensis reported from cats in Asia. Six other Babesia species have been reported from domestic cats: the dog-associated B. canis s.s., Babesia gibsoni, and B. vogeli, as well as Babesia lohae, Babesia microti, and Babesia vulpes. Phylogenetic relationships of all named species were assessed and are presented as trees. The relatively high prevalence of B. vogeli in clinically healthy cats (16% in Brazil, 13% on St Kitts, and 8.1% in Portugal) suggests that immunocompetent cats can harbor the infection with no discernible untoward effects. Reports of occurrence of B. felis and other Babesia species in domestic cats should be accepted only if they are supported by credible molecular provenance.

Detection of novel piroplasmid species and Babesia microti and Theileria orientalis genotypes in hard ticks from Tengchong County, Southwest China

To reveal the genetic diversity of Babesia microti and Theileria orientalis in Southwest China, we conducted a molecular survey of piroplasms in hard ticks in a China-Myanmar border county. Host infesting and questing ticks were collected from Tengchong County in 2013 and 2014. Piroplasm infection in ticks was detected by PCR, and then, phylogenetic analysis was conducted to study the genetic diversity of the pathogens identified in ticks. All in all, six piroplasm species comprising of B. microti; B. orientalis; a novel Babesia species designated Babesia sp. Tengchong, China; T. orientalis; T. luwenshuni; and an as yet undescribed piroplasmid species referred to as Piroplasmid sp. Tengchong, China, have been identified after screening goat- and cattle-attached ticks. In addition, B. bigemina has been identified by screening questing ticks. Phylogenetic analysis based on the 18S rRNA and partial β-tubulin gene revealed two novel potentially zoonotic genotypes designated B. microti Tengchong-Type A and B. The T. orientalis genotypes identified in the present study represent the seven known genotypes 1-5, 7, and N3 as revealed by phylogenetic analysis of 18S rRNA and MPSP genes. Importantly, an additional genotype designated N4 has also been identified in this study, which brings the number of recognized T. orientalis genotypes to a total of twelve. Thus, besides the two novel species, Babesia sp. Tengchong, China, closely related to Babesia species isolated from yak and Piroplasmid sp. Tengchong, China, our study demonstrates that additional novel B. microti and T. orientalis genotypes exist in Southwest China.

Tick-borne pathogens in Ixodidae ticks collected from privately-owned dogs in Italy: a country-wide molecular survey

Background

Ticks and tick-borne diseases are increasingly recognized as a cause of disease in dogs worldwide. The epidemiology of ticks and tick-transmitted protozoa and bacteria has changed due to the spread of ticks to urban and peri-urban areas and the movement of infected animals, posing new risks for animals and humans. This countrywide study reports information on distribution and prevalence of pathogens in ticks collected from privately-owned dogs in Italy.

We analyzed 2681 Ixodidae ticks, collected from 1454 pet dogs from Italy. Specific PCR protocols were used to detect i) Piroplasms of the genera Babesia and Theileria, ii) Gram-negative cocci of the family Anaplasmataceae and iii) Borrelia burgdorferi sensu lato. Sequencing of positive amplicons allowed for species identification.

Results

Babesia/Theileria spp. DNA was detected in 435 homogeneous tick-pools (Minimum Infection Rate (MIR) = 27.6%; 95% confidence interval (CI) = 25.4–29.8%) with higher prevalence in Ixodes ricinus and Rhipicephalus sanguneus group. The zoonotic B. venatorum was the most prevalent species (MIR = 7.5%; 95% CI = 6.3–9.0%). Anaplasma and Ehrlichia species were detected in 165 tick-pools (MIR = 10.5%; 95% CI = 9.3–11.8%) and specifically, A. phagocytophilum was identified with MIR = 5.1% (95% CI = 4.1–6.3%). Borrelia burgdorferi s.l. and B. afzelii were detected with MIR = 0.4% (95% CI = 0.2–0.8%) and MIR = 0.3% (95% CI 0.1–0.7%) respectively.

Conclusions

Zoonotic pathogens B. venatorum and A. phagocytophilum were the most frequently detected in ticks collected from privately-owned dogs which might be used as markers of pathogens presence and distribution.

Mitochondrial cytochrome oxidase C subunit III (cox3) gene as a sensitive and specific target for molecular detection of Babesia gibsoni infection in dogs

A PCR targeting mitochondrial cytochrome oxidase subunit III (cox3) for molecular detection of Babesia gibsoni infection in dogs has been developed in this study. Fifty blood samples from suspected clinical cases from dogs, brought to the veterinary college clinics, were examined for presence of B. gibsoni using conventional diagnosis by microscopic examination of Giemsa stained thin blood smears. In addition, species specific PCRs targeting ITS-1 region (BgITS-1 PCR) and nested PCR targeting 18S ribosomal RNA gene (Bg18SnPCR) were carried out. A 634 bp PCR fragment of B. gibsoni cox3 gene was amplified in positive samples from three geographical locations of Satara, Wai and Pune in Maharashtra state of India. From analysis of the sequence of the B. gibsoni cox3 gene, we found that the Indian isolate had 96-98% similarity to the isolate from Japan and China. Post sequencing, de-novo diagnostic primer pair for species specific amplification of 164 bp fragment of B. gibsonicox3 was designed and the PCR was standardized. The diagnostic results of de-novo Bgcox3 PCR were compared with BgITS-1 PCR and Bg18S nPCR. Thin blood smears detected 22% (11/50) samples positive for small form of Babesia species. The BgITS-1 PCR detected 25% samples (15/50) as positive and Bg18S nPCR detected 80% (40/50) B. gibsoni positive samples. The de-novo Bgcox3 PCR detected 66% (33/50) samples positive for B. gibsoni (at 95% CI). The analytical sensitivity of cox3 PCR was evaluated as 0.000003% parasitaemia or 09 parasites in 100  μl of blood. The de-novo diagnostic cox3 PCR did not cross react with control positive DNA from other haemoprotozoa and rickettsia like B. vogeli, Hepatozoon canis, Trypanosoma evansi, Ehrlichia canis and Anaplasma platys. Statistically, cox3 PCR had better diagnostic efficiency than ITS-1 PCR in terms of sensitivity (p = 0.0006). No statistically significant difference between results of cox3 PCR and 18S nPCR was observed (p = 0.1760). Kappa values estimated for each test pair showed fair to moderate agreement between the observations. Specificity of Bgcox3 PCR was 100% when compared with microscopy or BgITS-1 PCR. Sensitivity of Bgcox3 PCR was 100% when compared with that of Bg18S nPCR.

Prevalence of Babesia spp. and clinical characteristics of Babesia vulpes infections in North American dogs

Background

Babesiosis is an important cause of thrombocytopenia and hemolytic anemia in dogs. Babesia vulpes, reported in European dogs and North American foxes, rarely has been reported in domestic North American dogs. Newly optimized polymerase chain reaction (PCR) primers facilitate more sensitive amplification of B. vulpes DNA.

Objectives

To determine the prevalence of Babesia sp. infections in dogs being tested for Babesia infection, and to describe co‐infections and clinicopathologic abnormalities in B. vulpes positive dogs.

Animals

Dog blood or tissue samples (n = 9367) submitted to a diagnostic laboratory between June 2015 and June 2018 were tested using an optimized Babesia PCR assay.

Methods

Comprehensive canine vector‐borne disease diagnostic testing was performed on convenience samples.

Results

Babesia sp. DNA was amplified from 269/9367 (2.9%) North American dogs. Babesia sp. infections included B. gibsoni monoinfection (157; 1.7%), B. vulpes monoinfection (19; 0.20%), and B. gibsoni and B. vulpes coinfection (29; 0.31%). Forty‐three of the 48 total B. vulpes‐infected dogs were American Pit Bull Terrier‐type breeds, of which 36 historically were involved with dog fights. Coinfections with Mycoplasma, Dirofilaria immitis, or Wolbachia and coexposures to Bartonella, Ehrlichia, and Rickettsia spp. were documented in B. vulpes‐infected dogs. Clinicopathologic data in B. vulpes‐infected dogs both with and without coinfections included anemia, thrombocytopenia, hyperglobulinemia, hypoalbuminemia, and proteinuria.

Conclusions and Clinical Importance

Babesia vulpes infection in domestic North American dogs is commonly found in conjunction with other coinfections, including B. gibsoni and hemotropic Mycoplasma. Similar to B. gibsoni, dog‐to‐dog transmission of B. vulpes may be a frequent mode of transmission.