Babesia canis canis in dogs from Hungary: detection by PCR and sequencing

Molecular detection of Babesia spp. in dogs in Germany (2007-2020) and identification of potential risk factors for infection

BACKGROUND

In Europe, canine babesiosis is most frequently caused by Babesia canis and Babesia vogeli, and occasionally by Babesia gibsoni.. In Germany, B. canis is recognized as endemic. The aims of this study were to assess how often Babesia spp. infections were diagnosed in a commercial laboratory in samples from dogs from Germany, and to evaluate potential risk factors for infection.

METHODS

The database of the LABOKLIN laboratory was screened for Babesia spp.-positive polymerase chain reaction (PCR) tests for dogs for the period January 2007-December 2020. Sequencing was performed for positive tests from 2018 and 2019. Binary logistic regression analysis was performed to determine the effects of sex, season, and year of testing. Questionnaires were sent to the submitting veterinarians to obtain information on travel abroad, tick infestation, and ectoparasite prophylaxis of the respective dogs. Fisher's exact test was used to calculate statistical significance and P < 0.05 was considered statistically significant.

RESULTS

In total, 659 out of 20,914 dogs (3.2%) tested positive for Babesia spp. by PCR. Of 172 sequenced samples, B. canis was identified in 156, B. vogeli in nine, B. gibsoni in five, and B. vulpes in two. Season had a statistically significant impact on test results when summer/winter (1.6% tested positive) was compared to spring/autumn (4.7%), with peaks in April (5.2%) and October (7.4%) [P < 0.001, odds ratio (OR) = 3.16]. Sex (male 3.5%, female 2.8%; P = 0.012, OR = 1.49) and age (< 7 years old 4.0%, ≥ 7 years old 2.3%; P < 0.001, OR = 1.76) of the tested dogs also had a statistically significant effect. A statistically significant impact was demonstrated for observed tick attachment (P < 0.001, OR = 7.62) and lack of ectoparasite prophylaxis (P = 0.001, OR = 3.03). The frequency of positive Babesia spp. tests did not significantly differ between the 659 dogs that had never left Germany and the 1506 dogs with known stays abroad (P = 0.088).

CONCLUSIONS

The possibility of canine infection with B. canis needs to be especially taken into consideration in spring and autumn in Germany as the activity of the tick Dermacentor reticulatus, a potential vector for canine babesiosis, is highest in these seasons. Travel and importation of dogs are considered major factors associated with canine babesiosis in Germany. However, autochthonous Babesia spp. infections also occur in a considerable number of dogs in Germany.

Detection and Molecular Characterization of Canine Babesiosis Causative Agent Babesia canis in Naturally Infected Dogs in the Dobrogea Area (Southeastern Romania)

Canine babesiosis is an emerging tick-borne disease of major veterinary concern in Europe. Its prevalence has increased in the last two decades and is spreading rapidly toward the north. The aim of this study was to investigate the genetic diversity of Babesia spp. strains isolated from naturally infected dogs in a tick-endemic area (Dobrogea) in southeastern Romania. For this purpose, a total of twenty-three samples from dogs diagnosed with various clinical forms of babesiosis, evaluated by means of clinical history, physical examination, and hematological tests, were subjected to a molecular investigation using PCR, sequencing analysis, and genetic characterization. A microscopic examination of thin Diff-quick-stained blood smears revealed large intra-erythrocytic Babesia piroplasms in all dogs. The PCR and sequencing analysis results indicated the presence of Babesia canis in 22 dogs (95.7%) and Babesia vogeli in 1 dog (4.3%). Among the B. canis isolates, two genotypes were distinguished based on two nucleotide substitutions (GA→AG) observed in the 18S rRNA gene sequences (at positions 609 and 610), with the AG genotype predominating (54.5% of samples), while the GA variant was identified in 9.1% of samples. In the remaining isolates (36.4%), both variants were identified. The B. vogeli-positive dog also tested positive for antibodies against Ehrlichia canis and displayed severe disease. This study reports, for the first time, the presence of genetically heterogenic B. canis strains in dogs with clinical babesiosis in Romania. These findings provide a basis for future studies on the relationship between the genetic structure of the causative agents of canine babesiosis in Romania and the course of the disease.

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.

Multiple blood pathogen infections in apparently healthy sheltered dogs in southern Thailand

In developing countries such as Thailand, free-ranging dogs are frequently involved in road accidents and contribute to the cost of public healthcare. Shelters play a vital role in communities because they help to control the population of unwanted and free-ranging dogs. This study aimed to investigate blood pathogen infection in sheltered dogs, as it is one of the factors contributing to animal welfare. Blood samples were randomly collected from 141 dogs from the largest shelter (approximately 400–500 dogs in total) in southern Thailand. Blood pathogens were detected using both PCR and light microscopy. Four blood pathogens were identified: Anaplasma platys, Ehrlichia canis, Babesia canis vogeli, and Hepatozoon canis. No trypanosomes were detected. The incidence of blood parasite infection was 56.7% (80/141) by PCR, and 28.4% (40/141) by microscopy. E. canis was the most prevalent pathogen, accounting for 46.1% (65/141) of the cases, while multiple infections accounted for 22% (31/141) of the cases. A triple infection with E. canis, A. platys, and B. canis vogeli was observed in 5.7% (8/141) of the cases. Although PCR is far more sensitive than microscopy, it appears to have equivalent specificity. In conclusion, this study reported a high occurrence of blood pathogen infections in clinically healthy sheltered dogs. Many of them were infected with multiple pathogens and may have been infected before entering the shelter. These findings suggest that a blood test is necessary to screen dogs prior to their admission to the shelter to prevent disease transmission and enhance animal welfare.

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.

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

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

Seroprevalence and prevalence of Babesia vogeli in clinically healthy dogs and their ticks in Costa Rica

Canine babesiosis is a disease caused by a parasite of the genus Babesia which destroys red blood cells. Previous studies have shown the presence of Babesia vogeli in rural areas in Costa Rica using molecular techniques. The objective of the present study was to determine the seroprevalence and prevalence of B. vogeli in clinically healthy dogs and their ticks at the national level, both within and outside the Central Valley. Blood samples and ticks from 482 dogs were collected between June 2011 and May 2014, and analyzed by immunofluorescence assay (IFA) and real-time polymerase chain reaction (qPCR); two protocols of endpoint PCR and sequencing were used to confirm qPCR-positive samples. Seroprevalence of canine babesiosis of 5.3% (24/453) was determined at the national level, specifically 2.0% (5/253) within and 9.5% (19/200) outside the Central Valley, respectively. Real-time PCR determined a global prevalence of B. vogeli of 31.3% (125/400): 21.4% (47/220) within the Central Valley and 43.3% (78/180) outside the Central Valley. The endpoint PCR amplified only 10 of the 125 blood samples identified as positive in qPCR. One sample amplified by endpoint PCR was sequenced and identified as B. vogeli. Twelve canines were identified with past infections, seven canines with active infection, and 111 canines with early infection. Two species of ticks were found with B. vogeli: Rhipicephalus sanguineus sensu lato (n = 40) and Amblyomma ovale (n = 1). The prevalence of canine babesiosis at the national level, both within and outside the Central Valley, is reported here for the first time, determining the presence of the piroplasmid throughout the country, with a higher circulation of the agent outside the Central Valley. Only one species, B. vogeli, was detected in the blood of dogs and their ticks. Therefore, veterinarians should consider using qPCR to determine the presence of the parasite in blood donors and before starting treatment of vector-borne disease in dogs.

Prevalence and distribution of pathogen infection and permethrin resistance in tropical and temperate populations of Rhipicephalus sanguineus s.l. collected worldwide

The brown dog tick, Rhipicephalus sanguineus sensu lato (s.l.) Latreille (Acari: Ixodidae), is a peridomestic, cosmopolitan parasite of dogs known to vector numerous pathogens of veterinary and medical importance. Recent phylogenetic analyses separate this tick into temperate and tropical lineages. Populations of Rh. sanguineus s.l. have been reported to exhibit sodium channel target site insensitivity to permethrin and etofenprox, which is likely due to the prolonged use of pyrethroids against many pests in and around the home. In this study, populations collected in the Caribbean, Africa, Asia, Europe and North America, were tested to identify the distribution of a known resistance mechanism, pathogen-vector interactions and phylogeny in relation to latitude. Using molecular assays, populations from 29 distinct locations were simultaneously geographically typed and screened for bacterial infection by Rickettsia, Ehrlichia, Babesia and Hepatozoon species, and for the presence of a sodium channel single nucleotide polymorphism known to confer permethrin resistance. Implications of these results on Rh. sanguineus s.l. management in association with geographical distribution will be discussed.

Babesia canis spp. in dogs in Baghdad Province, Iraq: First molecular identification and clinical and epidemiological study

AIMS

The aim of this study was to investigate babesiosis in dogs of different breeds and ages and of both sexes in Baghdad Province by molecular detection of Babesia canis using conventional polymerase chain reaction (PCR) and sequencing followed by phylogenetic analyses.

MATERIALS AND METHODS

Blood samples were collected from 310 dogs of different ages and breeds, and of both sexes in different areas of Baghdad Province from December 2018 to September 2019; during clinical examinations, body temperature, pulse, respiratory rate, and signs of diseases were recorded. PCR was used to amplify a specific 450-bp fragment of the 18S rRNA gene of B. canis. PCR products were sequenced, and MEGA 6.0 software was used for analysis. Chi-square and odds ratio tests were used to investigate the prevalence and risk factors of babesiosis.

RESULTS

Clinical signs of babesiosis included paleness or icterus of the mucus membranes, tick infestation, and febrile illness during the acute and subacute phase. The prevalence of infection with B. canis was 5.1%, with the higher prevalence in male dogs and in dogs <3 years of age. Huskies were more likely to be infected than other dogs. Infection prevalence was highest in April and June and was higher in spring and summer than in winter. Using sequence data, 14 isolates of Babesia canis canis and one isolate of each Babesia canis rossi and Babesia canis vogeli were identified. Phylogenetic analyses of B. canis canis revealed that three shared clades and several isolated lineages were similar to other isolates (97-99% similarity), whereas B. canis vogeli and B. canis rossi showed similarities of 98% and 99% with isolates from other geographical regions.

CONCLUSION

This study provides the first molecular record and phylogenic analysis of B. canis in dogs in Iraq, and it will be valuable for confirming clinical signs and studying epidemiological risk factors of babesiosis in dogs.

Simultaneous differential detection of canine blood parasites: Multiplex high-resolution melting analysis (mHRM)

Recently, the incidence of canine infection by the tick-borne parasites Babesia spp., Hepatozoon canis, Ehrlichia canis and Anaplasma platys has been increasing globally. We have developed a multiplex high-resolution melting analysis (mHRM) technique to reduce the time demands and costs associated with detecting haemoparasites in canine blood, while increasing the degree of reliability of this method of analysis. We have designed primers that are specific for protozoans (B. vogeli and H. canis) and Rickettsia-like bacteria (E. canis and A. platys) based on the 18S or 16S rDNA sequences, respectively. Two primer pairs (Protz18S-C and Bact16S-A) were found to be suitable for detecting these agents since their melting temperatures (T_m) exhibited discernible differences among the four haemoparasites, A. platys, B. vogeli, E. canis and H. canis (83.10 °C, 82.41 °C, 80.37 °C and 78.56 °C, respectively). The sequences acquired from these PCR products were >94 % identical to those of A. platys, B. vogeli, E. canis and H. canis in GenBank. The limit of detection (LOD) for B. vogeli, E. canis and A. platys was 10³ copies/μl, while the LOD for H. canis was 10⁴ copies/μl. Of the 68 dogs tested, 28 (41 %) were infected with these agents. The most commonly occurring infection involved E. canis, followed by B. vogeli, A. platys and H. canis, with infection percentages of 26 %, 13 %, 7 % and 6 %, respectively. These results demonstrate that mHRM can serve as a rapid, economical and reliable tool for the detection of parasitic diseases in canine blood for diagnosis and epidemiology.

Genetic Diversity of Canine Babesia Species Prevalent in Pet Dogs of Punjab, Pakistan

Simple Summary

Babesiosis is caused by the intra-erythrocytic Babesia species in dogs. Different species are reported worldwide. The present study was conducted on pet dogs of two districts of Punjab, Pakistan, including Lahore and Narowal. Conventional microscopic and molecular tests, including conventional and nested PCR, were used for identification of diseased dogs and prevalent species. About 42% of dogs were tested positive for babesiosis and only two species including Babesia canis and gibsoni were prevalent.

Abstract

Canine babesiosis is a serious threat to dogs’ health worldwide, caused by the intra-erythrocytic Babesia species. The present study was carried out in pet dogs presented at three clinics of Lahore and one of Narowal in Punjab, Pakistan. Two hundred blood samples (50 from each clinic) were collected and screened by microscopy for Babesia spp. Out of 200 samples, 84 (42%) were found to be positive for babesiosis. The highest number of positive cases (50%) was recorded in dogs at Narowal clinic. Non-significant variation (p > 0.05) was observed in the prevalence of babesiosis in dogs in relation to sex and age. Positive samples were further confirmed by a polymerase chain reaction using 18S-rRNA genus-specific and species-specific primers. Amplicons were further analyzed by nucleotide sequencing for genetic diversity. Babesia canis and gibsoni were confirmed by genome sequencing in all diseased dogs. These isolates closely resembled each other, but differed from previous reported strains. In conclusion, pet dogs suffering from babesiosis were infected with B. canis and gibsoni, while in other countries, other Babesia species are also prevalent.

Development and validation of a multiplex, real-time PCR assay for Babesia rossi and Babesia vogeli

Canine babesiosis is caused by tick-transmitted intraerythrocytic protozoan parasites occurring worldwide. In southern Africa, babesiosis is caused by Babesia rossi and B. vogeli and is one of the most common and important infectious diseases affecting dogs. There is no reliable, rapid and sensitive method for the detection of these parasites, especially when parasitaemia is low. The aim of this study was to develop a sensitive and specific multiplex TaqMan® MGB PCR assay for the diagnosis of canine babesiosis infections occurring in southern Africa, and to discriminate between Babesia rossi and B. vogeli. The fitness of purpose of the assay was to confirm diagnosis of suspect or clinical cases, and estimate prevalence of infection for research purposes. A total of 648 published sequences were used to design the assay. A set of group-specific canine Babesia spp. primers were designed to amplify a 117 nucleotide region of the 18S rRNA gene of all canine Babesia spp. Species-specific TaqMan® MGB probes were developed for B. rossi, B. vogeli, B. canis and B. gibsoni, but analytical validation was only performed for B. rossi and B. vogeli as a multiplex assay. The assay had a broad dynamic range and amplified B. rossi and B. vogeli efficiently (98.6% and 94.7% respectively). The assay was sensitive, with a 95% LOD of 10^-2.67% parasitized erythrocytes (PE) for B. rossi and 10^-2.03% PE for B. vogeli, and specific, with no cross reaction between B. rossi and B. vogeli and no detection of other haemoparasites that infect dogs, such as Ehrlichia canis and Anaplasma platys. Consistent repeatability within and between PCR runs was shown. This assay will be able to accurately and rapidly confirm babesiosis in canines and allow for treatment to be administered in the early stages of the disease, speeding up the recovery time in affected dogs.

Evaluation of multiplex PCR assay for detection of Babesia spp, Ehrlichia canis and Trypanosoma evansi in dogs

A multiplex PCR test was evaluated to detect the DNA of three important dog haemoparasites by comparing with singular PCR counterpart on clinical blood samples of dogs in and around Chennai, Tamil Nadu, India. Initial screening of samples was done by microscopic examination of peripheral blood smear and singular PCR and those found exclusively positive for Babesia spp, Ehrlichia canis and Trypanosoma evansi and concurrent infections were used to standardize multiplex PCR. Amplicons of 619 bp, 377 bp and 227 bp corresponding to Babesia spp (18S rRNA gene), E. canis (VirB9 gene), and T.evansi (VSG gene) respectively were amplified, without any non-specific amplification. The laboratory sensitivity (91.7% to 100%) and specificity (100%) of the multiplex PCR were calculated using 'true positive' and 'true negative' dog blood samples obtained in the initial screening process. Clinical blood samples from 287 dogs were screened using singular PCR and multiplex PCR tests for the presence of genome of Babesia spp, E. canis and T. evansi. The multiplex PCR was found to have high level of diagnostic specificity (97.5%-100%) in the detection of all three dog blood parasites and high level of diagnostic sensitivity (95%) in the detection of T. evansi from field level clinical blood samples compared to the singular PCR. However, the diagnostic sensitivity of the multiplex PCR was found to be low to moderate (40.45%-66.7%) in detection of Babesia spp and E. canis from field level clinical blood samples. The strength of agreement between singular and multiplex PCR assays was 'moderate' (0.445), 'good' (0.708) and 'very good' (0.968) in detection of DNA of Babesia spp, E. canis and T. evansi. The multiplex PCR was found to be 10 fold less sensitive in comparison with the singular PCR counterpart.

Prevalence and distribution of Borrelia and Babesia species in ticks feeding on dogs in the U.K

Ticks were collected during March-July 2015 from dogs by veterinarians throughout the U.K. and used to estimate current prevalences and distributions of pathogens. DNA was extracted from 4750 ticks and subjected to polymerase chain reaction and sequence analysis to identify Borrelia burgdorferi sensu lato (Spirochaetales: Spirochaetaceae) and Babesia (Piroplasmida: Babesiidae) species. Of 4737 ticks [predominantly Ixodes ricinus Linneaus (Ixodida: Ixodidae)], B. burgdorferi s.l. was detected in 94 (2.0%). Four Borrelia genospecies were identified: Borrelia garinii (41.5%); Borrelia afzelli (31.9%); Borrelia burgdorferi sensu stricto (25.5%), and Borrelia spielmanii (1.1%). One Rhipicephalus sanguineus Latreille (Ixodida: Ixodidae), collected from a dog with a history of travel outside the U.K., was positive for B. garinii. Seventy ticks (1.5%) were positive for Babesia spp. Of these, 84.3% were positive for Babesia venatorum, 10.0% for Babesia vulpes sp. nov., 2.9% for Babesia divergens/Babesia capreoli and 1.4% for Babesia microti. One isolate of Babesia canis was detected in a Dermacentor reticulatus (Ixodida: Ixodidae) tick collected from a dog that had recently travelled to France. Prevalences of B. burgdorferi s.l. and Babesia spp. did not differ significantly between different regions of the U.K. The results map the widespread distribution of B. burgdorferi s.l. and Babesia spp. in ticks in the U.K. and highlight the potential for the introduction and establishment of exotic ticks and tick-borne pathogens.

Detection of Ehrlichia, Anaplasma, and Babesia spp. in dogs of Cebu, Philippines

Background

Ehrlichia, Anaplasma, and Babesia spp. are canine pathogens transmitted by the Rhipicephalus sanguineus tick which can cause varied clinical signs. These pathogens have been investigated in the Philippines, but coinfection has not been reported yet.

Aim

The aim of this study was to evaluate the presence of Ehrlichia/Anaplasma and Babesia spp. in Philippine dogs.

Materials and Methods

A total of 100 dogs from seven different veterinary establishments in Cebu, Philippines, were examined for Ehrlichia/Anaplasma and Babesia spp. infection using peripheral blood smear examination and polymerase chain reaction (PCR). Inclusion criteria included a history or presence of tick infestation, anemia, and/or thrombocytopenia. Clinical signs were recorded. Statistical analyses were performed between PCR positivity and clinical signs and hematological results.

Results

A total of 10 and 18 dogs were found to be positive for Ehrlichia/Anaplasma and Babesia spp., respectively. One animal was PCR positive for both pathogens, which is the first report of coinfection in the country. The most common clinical signs observed include inappetence (89%), lethargy (80%), thrombocytopenia (85%), and anemia (74%). Analyses revealed that inappetence (p=0.044) and weight loss (p=0.028) were found statistically significant with Ehrlichia/Anaplasma infection. Basophil (p=0.001) and eosinophil counts (p=0.000) were also found significantly different between Ehrlichia/Anaplasma spp.-positive and -negative dogs. On the other hand, differential monocyte count (p=0.009) was found significantly different between Babesia spp.-positive and -negative dogs.

Conclusion

The present study showed low infection rates of canine ehrlichiosis/anaplasmosis and babesiosis and provided additional evidence for the presence of the pathogens in the area.

First molecular detection of Babesia canis in dogs from Bosnia and Herzegovina

Babesia spp. are tick-transmitted protozoan haemoparasites of great economic, veterinary and medical impact worldwide. Herein we reported the very high prevalence of autochthonous babesiosis in symptomatic dogs from Bosnia and Herzegovina in the period from 2014 to 2016. Eighty dogs that did not leave the country were examined using parasitological and molecular analyses and babesiosis was diagnosed in 82.5% and 85.0% of them, respectively (p < 0.001). One species, Babesia canis was identified using molecular methodology (PCR and sequence analysis). Statistical analyses showed that epizootiological characteristics have no influence on the possibility of infection. Agglomerative hierarchical clustering (AHC) analyses used for comparing the symptoms and clinical signs of infection in dogs pointed out that a high degree of anemia, followed by thrombocytopenia (89%), lethargy (100%), loss of appetite (95%), fever (66%) and icterus (61%) was dominant. In addition, results of the statistical analysis performed showed that more dogs with no data of tick prophylaxis (70%) were found Babesia infected. Those results point to further intensified epizootic surveys in the territory of Bosnia and Herzegovina.

Emergence of Babesia canis in southern England

Background

The United Kingdom is considered free of autochthonous transmission of canine babesiosis although cases are reported in dogs associated with recent travel abroad. During the winter months of 2015/16, a cluster of cases of disease in dogs with signs suggestive of canine babesiosis were reported in Harlow, Essex.

Methods

Babesia species were detected in dog blood samples by Giemsa staining of blood smears and by pan-piroplasm PCRs. Babesia species were also detected in extracts of tick DNA using pan-piroplasm PCRs. DNA sequencing and phylogenetic analysis was used to confirm the species of Babesia present in dog blood and tick samples. Tick species were identified by PCR-sequencing based on amplification of the cytochrome c oxidase subunit one (cox1) gene. Dermacentor reticulatus ticks were sampled from field sites in England and Wales.

Results

Blood smear analysis on samples taken from some of the affected dogs confirmed the presence of a large Babesia species within erythrocytes. A tick recovered from one of these cases was identified as Dermacentor reticulatus, a species with a limited distribution in England and Wales, but a known vector of canine babesiosis in continental Europe. Babesia canis was subsequently identified in blood samples obtained from three clinical cases (all dogs) within the area and from ticks associated with these dogs. A field survey detected 17 adult D. reticulatus ticks from one area visited by the affected dogs. Fourteen of these ticks were shown to be positive for the B. canis parasite, implicating them as a potential source for babesiosis in Harlow. In order to assess whether the parasite is present in more than one tick population, D. reticulatus ticks from across England and Wales were screened for the presence of Babesia species. In addition to the Harlow site, a further five locations where D. reticulatus is present were screened for Babesia species. Babesia was not detected from most sites tested but one tick from a single location in Wales was positive for B. canis.

Conclusions

Infection with B. canis was confirmed in a number of dogs in Harlow, Essex, with no history of travel outside of the country. The same pathogen was identified in field-caught D. reticulatus ticks in the same area and is considered the likely source of infection. This highlights the need for vigilance by veterinary surgeons for future outbreaks of tick-borne disease in dogs.

Critical analysis of vector-borne infections in dogs: Babesia vogeli, Babesia gibsoni, Ehrlichia canis and Hepatozoon canis in Punjab, India

There are few published studies on various vector borne diseases of dogs in India and most depict clinical infection in dogs, diagnosed by observation of the haemopathogens in stained blood smears. This study provides the first report regarding molecular confirmation and ancestral relationship analysis of blood smears positive cases of assorted haemopathogens in Punjab province of India. On blood smear examination, haemopathogens were observed in 124 out of 778 (15.95%, 95% CI: 13.53- 18.68) blood smears. Further polymerase chain reactions (PCR) was used on bloods smear positive cases to validate the results. Out of 778 blood samples, Babesia gibsoni was most common parasite infecting dogs (15.04%, 95% CI: 12.7-17.72), followed by Ehrlichia canis (0.39%, 95% CI: 0.0-1.13), infection of Babesia vogeli and Hepatozoon canis was same (0.26%, 95% CI: 0.0-0.9). Among various risk factors studied (age, sex, season), prevalence of infection was non-significantly higher in 1-2 year of age group (19.88%, 95% CI: 14.45-26.71), regarding sex same prevalence was recorded (15.94%), and chances of infection was highest in pre-monsoon i.e. summer (18.26%, 95% CI: 14.49-22.76). Phylogenetic analysis revealed ancestral background of Ludhiana isolates of B. vogeli, B. gibsoni, H. canis, and E. canis with the isolates of Philippines, Mongolia and Tunisia.

WITHDRAWN:First report on Babesia canis vogeli infection in dogs in the Philippines

The Publisher regrets that this article is an accidental duplication of an article that has already been published, http://dx.doi.org/10.1016/j.parint.2016.10.001.The duplicate article has therefore been withdrawn. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.

A new quantitative PCR method for the detection of Anaplasma platys in dogs based on the citrate synthase gene

Anaplasma platys is an obligate intracellular bacterium that primarily affects dogs, but it can also infect humans. Our study aimed to standardize a quantitative real-time (q)PCR method using the citrate synthase gene (gltA) as a specific target for A. platys detection in naturally infected dogs. Primers (gltA84F and gltA84R) and probe (PLATYSp) were designed to amplify an 84-bp fragment based on the gltA gene sequences of A. platys available in GenBank. A total of 186 dog blood samples originating from the Brazilian state of Rio de Janeiro were tested by qPCR. Additionally, the same samples were tested by cytology and a nested (n)PCR that targeted the 16S ribosomal DNA to determine the performance of our qPCR method compared to these existing techniques. Among the samples tested with qPCR, 17.2% were considered positive, significantly more than detected by nPCR (14.0%). Under optical microscopy, inclusions were observed in platelets of 25.3% of the samples, and among these samples, only 33.9% were identified as positive for A. platys using qPCR. The qPCR technique proved to be more specific than cytology and to have superior sensitivity to nPCR for detecting A. platys in dogs. The development of this new qPCR method contributes to the advancement of research involving A. platys Furthermore, it can be used to quantify the presence of this bacterium to evaluate the treatment of infected animals, or even as a more sensitive and specific tool for situations indicating possible clinical disease but with negative cytology.

Dermacentor reticulatus: a vector on the rise

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

Canine vector-borne pathogens in semi-domesticated dogs residing in northern Cambodia

Background

In Southeast Asia, the canine vector-borne pathogens Babesia spp., Ehrlichia canis, Anaplasma platys, Hepatozoon canis, haemotropic mycoplasmas and Dirofilaria immitis cause significant morbidity and mortality in dogs. Moreover, dogs have also been implicated as natural reservoirs for Rickettsia felis, the agent of flea-borne spotted fever, increasingly implicated as a cause of undifferentiated fever in humans in Southeast Asia. The objective of this study was to determine the prevalence and diversity of canine vector-borne pathogens in 101 semi-domesticated dogs from rural Cambodia using molecular diagnostic techniques.

Results

The most common canine vector-borne pathogens found infecting dogs in this study were Babesia vogeli (32.7 %) followed by Ehrlichia canis (21.8 %), Dirofilaria immitis (15.8 %), Hepatozoon canis (10.9 %), Mycoplasma haemocanis (9.9 %) and “Candidatus Mycoplasma haematoparvum” (2.9 %). A high level of co-infection with CVBD agents (23.8 %) was present, most commonly B. vogeli and E. canis. Naturally occurring R. felis infection was also detected in 10.9 % of dogs in support of their role as a natural mammalian reservoir for flea-borne spotted fever in humans.

Conclusions

This study reports for the first time, the prevalence and diversity of CVBD pathogens in dogs in Cambodia. In total, five species of CVBD pathogens were found infecting semi-domesticated dogs and many were co-infected with two or more pathogens. This study supports the role of dogs as natural mammalian reservoirs for R. felis, the agent of flea-borne spotted fever in humans.

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.

Canine Babesioses in Noninvestigated Areas of Serbia

During the years 2012-2014, a total of 158 outdoor dogs from Pančevo and Đurđevo (northern Serbia) and Niš and Prokuplje (southern Serbia) were submitted to molecular analyses (PCR and sequencing) for canine babesioses. An overall prevalence of 21.5% was found, due to the species Babesia sp. 'spanish dog' (10.1%), B. gibsoni (5.7%), B. canis vogeli (1.9%), B. caballi (1.9%), and B. microti (1.9%). In addition, sequence analysis showed the presence of Hepatozoon canis in a dog from Niš. No significant difference between infected and noninfected dogs was found by age, sex, and place of residence, whereas there was difference regarding the presence of ticks (p<0.005) and application of preventive measures such as applying of antitick drugs/devices. Moreover, a significant difference was established by area: Dogs from Prokuplje showed infection rates (59.1%) higher than dogs from Pančevo (11.9%), Niš (4.5), and Đurđevo (where infected dogs were not found), and a different geographical distribution of the species was found. The presence of so many Babesia species and the first identification of H. canis will allow investigations on the pathogenic role played by each one and suggests entomological studies on the tick species that are more suitable vectors for each of them. Finally, the presence of so many infected dogs offers the opportunity of evaluating the hypothesis of a possible zoonotic role of babesial species affecting dogs.

First molecular identification of Babesia gibsoni in dogs from Slovakia, central Europe

Canine babesiosis is a severe and potentially life threatening infection. In Europe, Babesia canis is considered to be the most common species responsible for the disease. We report two cases of babesiosis caused by Babesia gibsoni. The polymerase chain reaction, restriction fragment length polymorphism analysis and further sequencing of 18S rRNA gene fragments from blood samples of both dogs revealed the identity of isolates with B. gibsoni genotypes from other dogs worldwide. This species was previously not known to infect dogs in Slovakia. It is resistant to traditional anti-babesial therapy. Therefore, correct diagnosis is crucial for the successful treatment, especially in dogs with hemolytic anemia and febrile conditions.

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.

Seroprevalence of some vector-borne infections of dogs in Hungary

The first comprehensive study on the prevalence of canine vector-borne pathogens (Anaplasma phagocytophilum, Borrelia burgdorferi, Ehrlichia canis, and Dirofilaria immitis) was carried in Hungary because, except for babesiosis and dirofilariosis caused by Dirofilaria repens, there were no data on their regional distribution and prevalence. In 2011 and 2012, 1305 blood samples were collected from randomly selected, apparently healthy pet dogs in 167 localities of 19 counties of Hungary. All sera samples from dogs were screened for simultaneous qualitative detection of circulating antibodies to E. canis and B. burgdorferi sensu lato and A. phagocytophilum and D. immitis antigen using SNAP(®) 4Dx (IDEXX Laboratories). Overall, 170 dogs (13.0%; 95% confidence interval [CI] 11-15) were serologically positive to one or more of the tested pathogens. A. phagocytophilum was the most prevalent pathogen detected in 102 dogs by antibody titers (7.9%, 95% CI 6.5-9.5), followed by D. immitis (2.4%, 95% CI 1.0-4.0, n=64) and B. burgdorferi (0.4%, 95% CI 0.0-1.1, n=11) out of 1305 tested dogs. The least prevalent infection was with E. canis, with only two positive dogs (0.16%, 95% CI 0.03-0.6). Co-infection was found in eight dogs (0.61%, 95% CI 0.29-1.21), of which seven were seropositive to two pathogens (five with A. phagocytophilum and D. immitis, two with A. phagocytophilum and B. burgdorferi). One dog was serologically positive to three pathogens (A. phagocytophilum, B. burgdorferi, and D. immitis). Purebred and crossbred animals did not show significantly different levels of seropositivity. There was no significant association between the gender and the results of diagnostic testing. Logistic regression analysis showed a higher chance of seropositivity in the older dogs.

Fatal acute babesiosis in captive grey wolves (Canis lupus) due to Babesia canis

Two adult male Eurasian grey wolves belonging to a group of 12 animals, kept in an open air 15,000-m(2) enclosure at the Bear Farm facility near Veresegyháza, Hungary, were found dead in September 2002. Another 2 wolves died during the same period, but laboratory examination of their carcasses was not possible. During necropsy both animals were found to be in a good body condition. Oral mucosa, conjunctiva, sclera, and subcutaneous tissues revealed severe jaundice. The liver, gall bladder, and spleen were enlarged. The kidneys were paler than normal, and petechial haemorrhages were also seen under their fascia. Small, round Babesia-like organisms, 1.5-2 μm in diameter, were demonstrated in large numbers in stained impression smears made from the spleens of both animals. PCR amplification and sequencing identified Babesia canis. There are very few reports on babesiosis in the grey wolf, and our findings draw attention to the potential threat posed by B. canis that will probably have to be taken into account in future ex situ and in situ wolf conservation efforts.

Prevalence of Babesia and Anaplasma in ticks infesting dogs in Great Britain

Ticks are important vectors of disease in companion animals and transmit an extensive range of viral, bacterial and protozoan pathogens to dogs and cats. They may also be vectors of zoonotic pathogens which affect the health of in-contact owners. In recent years, babesiosis, and anaplasmosis have all shown signs of increased prevalence and distribution in various parts of Europe. Here, the prevalence of Anaplasma spp. and Babesia spp. pathogens in Ixodes ticks, collected from dogs in the UK in 2009, were evaluated using PCR and sequence analysis of the 16S rDNA or 18S rDNA regions respectively. Species identification was performed by alignment with existing sequences in GenBank. After sequencing, 5 out of 677 tick samples (0.74%) contained rDNA which shared 97-100%% sequence homology with Anaplasma phagocytophilum. Of these, three samples came from Ixodes ricinus and two from Ixodes hexagonus. Sixteen out of 742 ticks (2.4%) were positive for Babesia and of these 11 showed 97-100% homology with B. gibsoni. All of these 11 samples were derived from I. ricinus. One sample, again from I. ricinus, showed 99% homology for B. divergens. Four of the Babesia spp sequences were of the "venatorum" or EU1 type, three of which came from I. ricinus and one from an Ixodes canisuga. This strain has been associated with severe human cases of babeisiosis. A further 246 positive results, which appeared to show the presence of Anaplasma following PCR, were shown by sequence analysis to be derived from the bacterium Candidatus "Midichloria mitochondrii", which to date has been assumed to be non-pathogenic. The results are of interest because the presence of B. gibsoni in the UK further confirms the worldwide distribution of this piroplasm and supports the inference that I. ricinus may act as a vector for Babesia of the gibsoni-complex.

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

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

Babesia infection in naturally exposed pet dogs from a north-eastern state (Assam) of India: detection by microscopy and polymerase chain reaction

The objective of the study was to detect Babesia infections in pet dogs of a north-eastern state of India. The diagnostic efficacy of Babesia infection by polymerase chain reaction (PCR) technique has been compared with microscopy examination. For this, a total of 111 blood samples of pet dogs presented at clinical complex of the College of Veterinary Science, Guwahati, Assam with clinical signs suspected for Babesia infection subjected to the study. A total of 44 (39.63 %) dogs were diagnosed as positive for Babesia infections after microscopic examination. Among these, Babesia canis infection was diagnosed in 5 dogs (4.50 %) and B. gibsoni infection in 39 (35.13 %) dogs microscopically in Giemsa stained blood smears. Molecular diagnosis using PCR detected 63 (56.75 %) dogs positive for Babesia infection. Single infection with B. canis was found in 9 (8.10 %) dogs while B. gibsoni alone was detected in 3 (2.70 %) dogs. Mixed infections by both these species were detected in 51 (45.94 %) dogs. Overall, PCR detected 54 (48.64 %) dogs as B. gibsoni and 60 (54.05 %) dogs as B. canis positive.

Detection and molecular characterization of piroplasms species from naturally infected dogs in southeast Brazil

Rangelia vitalii is a protozoon described from dogs in the south and southeast regions of Brazil. It is phylogenetically related to Babesia spp. that infects dogs, but data on this enigmatic parasite is still limited. The aim of this work was to detect piroplasm species in dogs in the state of Rio de Janeiro, Brazil, by 18S rRNA gene-based PCR assay, restriction fragment length polymorphism (RFLP) and sequence analyses. Of 103 dogs examined, seven (6.8%) were positive for Babesia spp. by PCR. The amplified products were digested by restriction enzymes to differentiate the Babesia species, and one sample was identified as Babesia vogeli. The pattern observed for the other six amplification products did not match with pattern described for large Babesia infecting dogs. Sequencing analysis confirmed these six samples as R. vitalii, with high homologies (99-100%) with a sequence from south Brazil. This study confirms the presence of Babesia vogeli and Rangelia vitalii circulate in domestic dogs in Teresópolis, Rio de Janeiro, Brazil.

Canine babesiosis in Romania due to Babesia canis and Babesia vogeli: a molecular approach

Canine babesiosis is a tick-borne disease caused by the protozoa Babesia spp. that affects dogs worldwide. In Romania, canine babesiosis has become quite frequent in the last few years, with a wide variety of clinical signs, ranging from mild, nonspecific illness to peracute collapse, and even death. Traditionally, a Babesia infection in dogs is diagnosed based on the morphologic appearance of the intraerythrocytic piroplasms observed in peripheral blood smears. To date, no data on genetic characterization of Babesia species in dogs has been documented for Romania. Therefore, a molecular survey on natural Babesia infections of dogs in Romania using polymerase chain reaction and genetic sequence analysis of a fragment of the ssRNA gene was performed. A total number of 16 blood samples were tested for the presence of Babesia DNA. Blood samples were collected from 11 dogs with symptoms of babesiosis and microscopically proven positive for Babesia and from a group of five asymptomatic dogs, not tested microscopically for Babesia, which were included in the study for comparative analysis. The piroplasm-specific PCR amplifying the partial 18S rRNA gene confirmed Babesia spp. infection in all 11 samples from dogs with clinical babesiosis, and in one of the clinically normal dogs. Sequence analysis revealed the presence of Babesia canis in all clinically affected dogs and Babesia vogeli in one clinically normal dog. This is the first molecular evidence of B. canis and B. vogeli in dogs from Romania. The results of the study provide basic information toward a better understanding of the epidemiology of canine babesiosis in Romania and will help to promote an effective control program.

Epidemiological aspects on vector-borne infections in stray and pet dogs from Romania and Hungary with focus on Babesia spp

Canine arthropod-borne infections are of major interest in small animal practice and have been widely investigated in Central and Western Europe. However, only limited epidemiological data are available from South-Eastern European countries, although diseases including babesiosis or dirofilariosis are widely recognised as important canine infections in these countries. A steadily increasing number of dogs imported from South-Eastern Europe into Germany require particular attention by small animal practitioners. In this study, a total of 216 dogs [29 local Romanian pet dogs presented at Salvavet Veterinary Clinic in Bucharest, Romania, and 187 imported stray dogs from Romania (n = 109) and Hungary (n = 78) into Germany] were screened by molecular biological, serological and haematological methods for canine arthropod-borne infections. Eleven different parasitic and bacterial vector-borne pathogens-Babesia canis canis, Babesia canis vogeli, Babesia gibsoni, Babesia felis-like, Hepatozoon canis, Leishmania spp., Dirofilaria immitis, Dirofilaria repens, Acanthocheilonema reconditum, Anaplasma phagocytophilum and Mycoplasma haemocanis-were detected. Fifty-six percent of the dogs were positive by direct methods. B. canis canis was the most prevalent pathogen in dogs imported to Germany (42.8%) and dogs submitted for clinical consultation in Bucharest (44.8%). Our data strongly suggest the introduction of an adjusted screening panel in dogs from South-East Europe in view of increasing importation of dogs into Germany.

Polymerase chain reaction confirmation of Babesia canis canis and Anaplasma phagocytophilum in dogs suspected of babesiosis in Slovakia

Canine babesiosis was considered an imported tick transmitted disease until the first case of autochthonous canine babesiosis in Slovakia was described in 2002. Since then, the number of cases kept increasing every year. The causative agent of babesiosis in dogs is not yet characterized; therefore, the aim of our study was to determine the agent and the rate of infection in the vector tick D. reticulatus in Slovakia. Babesia canis canis was detected in 80 out of 87 blood samples from dogs with clinical manifestations of babesiosis. Six dogs suspected of babesiosis tested positive for presence of Anaplasma phagocytophilum, and one mixed infection of B. c. canis and A. phagocytophilum was detected. B. c. canis was detected in 35.6% questing adults of D. reticulatus. The obtained sequences from blood samples showed 99.7% and from D. reticulatus, 99.4% similarity with the B. c. canis (AY072926) from dogs infected in Croatia. In our study, we characterized the agent of canine babesiosis from blood samples of naturally infected dogs and D. reticulatus, the vector tick. Further, the presence of A. phagocytophilum, bacterium responsible for the canine granulocytic anaplasmosis, was recorded in dogs for the first time in Slovakia.

Babesiosis in dogs and cats--expanding parasitological and clinical spectra

Canine babesiosis caused by different Babesia species is a protozoal tick-borne disease with worldwide distribution and global significance. Historically, Babesia infection in dogs was identified based on the morphologic appearance of the parasite in the erythrocyte. All large forms of Babesia were designated Babesia canis, whereas all small forms of Babesia were considered to be Babesia gibsoni. However, the development of molecular methods has demonstrated that other Babesia species such as Babesia conradae, Babesia microti like piroplasm, Theileria spp. and a yet unnamed large form Babesia spp. infect dogs and cause distinct diseases. Babesia rossi, B. canis and Babesia vogeli previously considered as subspecies are identical morphologically but differ in the severity of clinical manifestations which they induce, their tick vectors, genetic characteristics, and geographic distributions, and are therefore currently considered separate species. The geographic distribution of the causative agent and thus the occurrence of babesiosis are largely dependent on the habitat of relevant tick vector species, with the exception of B. gibsoni where evidence for dog to dog transmission indicates that infection can be transmitted among fighting dog breeds independently of the limitations of vector tick infestation. Knowledge of the prevalence and clinicopathological aspects of Babesia species infecting dogs around the world is of epidemiologic and medical interest. Babesiosis in domestic cats is less common and has mostly been reported from South Africa where infection is mainly due to Babesia felis, a small Babesia that causes anemia and icterus. In addition, Babesia cati was reported from India and sporadic cases of B. canis infection in domestic cats have been reported in Europe, B. canis presentii in Israel and B. vogeli in Thailand. Babesiosis caused by large Babesia spp. is commonly treated with imidocarb dipropionate with good clinical response while small Babesia spp. are more resistant to anti-babesial therapy. Clinical and parasitological cure are often not achieved in the treatment of small Babesia species infections and clinical relapses are frequent. The spectrum of Babesia pathogens that infect dogs and cats is gradually being elucidated with the aid of molecular techniques and meticulous clinical investigation. Accurate detection and species recognition are important for the selection of the correct therapy and prediction of the course of disease.

West-to-east differences of Babesia canis canis prevalence in Dermacentor reticulatus ticks in Slovakia

Babesia canis canis is the most frequent causative agent of canine babesiosis in Central Europe, frequently causing severe disease. Recently, many new endemic foci of this disease have been reported from European countries. Growing incidence of canine babesiosis was recorded also in Slovakia during the last decade, from first cases in eastern Slovakia ten years ago to recent cases all over the south of the country. We have used nested PCR-RFLP method to study prevalence of B. c. canis in its natural tick vector Dermacentor reticulatus, collected at three geographically isolated lowland areas of southern Slovakia situated in the southeast, southwest, and west of Slovakia, respectively. The highest prevalence of B. c. canis was observed in D. reticulatus from eastern Slovakia (14.7%; n=327), whereas the prevalence in southwest was significantly lower (2.3%; n=1205). Notably, all 874 D. reticulatus ticks collected at Záhorská nížina lowland (W Slovakia) were B. c. canis-negative. Recorded differences in Babesia prevalence concurs well with the shift in incidence of clinical cases of canine babesiosis as observed by vet practitioners. Presented results revealed that eastern Slovakia represents an area of high risk of B. c. canis infection, whereas western areas of the country still remain Babesia canis-free.

Diversity of Babesia and Theileria species in symptomatic and asymptomatic dogs in Croatia

Babesiosis, the disease caused by tick-borne hematozoan parasites of the genus Babesia, is particularly common in dogs, and is caused by several "large" species of Babesia, as well as by an increasing number of "small" species of Babesia, some of which appear to be more closely related to members of the genus Theileria. In this work, blood samples were collected from 848 randomly selected, asymptomatic dogs and from 81 symptomatic dogs, microscopically positive for Babesia, and characterised by PCR and sequence analysis of a fragment of the ssrRNA gene. A prevalence of 3.42% (29 of 848) was found in asymptomatic dogs and sequence analysis revealed the presence of Babesia canis canis in 20 dogs (69%), Babesia gibsoni in six dogs (21%), Babesia canis vogeli in two dogs (7%) and Theileria annae in one dog (3%). In the group of symptomatic dogs, which were all positive by PCR, B. canis canis was the predominant species (78 dogs, or 96%), followed by single infections with B. canis vogeli, Babesia caballi and Theileria equi. Our study has confirmed that dogs are infected with a wide range of both large and small piroplasm species and subspecies, including B. caballi and T. equi, two parasites usually found in horses. The detection of the pathogenic species B. canis canis and B. gibsoni in asymptomatic dogs indicates that the relationship between parasite species/subspecies and clinical signs of infection in dogs deserves further investigation. Finally, the identities of the tick vectors transmitting T. annae and B. caballi remain to be elucidated.

Molecular evidence of natural infection with Babesia canis canis in Croatia

The aim of the present study was to detect and characterise the species and subspecies of Babesia spp. that cause canine babesiosis in Croatia. Twenty-eight dogs with typical signs of babesiosis (lethargy, anorexia, fever, dark urine and thrombocytopenia) were included in this study. Their blood smears showed the presence of Babesia canis . The results showed the detection of one subspecies, namely Babesia canis canis using PCR, and subsequent sequence analysis demonstrated portions of the nss rRNA gene in 27 out of 28 samples. Sequence analysis of the isolates showed 100% identity in 11 samples, 99.7% identity (one nucleotide difference) in 11 samples and 99.4% identity (two nucleotides difference) in 5 samples with B. canis canis . The results of this study confirm the presence of B. canis canis in infected dogs in Croatia and demonstrate a slightly new genetic variant of Babesia subspecies.

Detection of the DNA of Borrelia afzelii, Anaplasma phagocytophilum and Babesia canis in blood samples from dogs in Warsaw

Each month, from March 2003 to February 2004, 34 blood samples from dogs were randomly selected from the blood samples delivered to two veterinary laboratories in Warsaw and tested for the DNA of Borrelia burgdorferi sensu lato, Anaplasma phagocytophilum, Babesia canis and Hepatozoon canis. Borrelia DNA was detected in seven of the 408 dogs, A phagocytophilum DNA was found in two, and B canis DNA was found in 48 (11.8 per cent). The DNA of H canis was not found in any of the blood samples. Sequencing of the seven Borrelia amplicons showed that only the genospecies Borrelia afzelii was present, the first time it has been detected in dogs in Poland.

Detection of erythrocyte binding IgM and IgG by flow cytometry in sick dogs with Babesia canis canis or Babesia canis vogeli infection

The aim of this study was to examine by means of flow cytometry immunophenotyping (FCI) if sick dogs infected with Babesia canis canis (B. c. canis) or Babesia canis vogeli (B. c. vogeli) had anti-erythrocyte membrane binding IgG and/or IgM at the time of diagnosis. Diagnosis of Babesia infection was assessed by blood smear and by PCR-restriction fragment length polymorphism analysis in 30 sick dogs. Signalment, clinical history, physical examination and laboratory tests of B. c. canis (n=24) and of B. c. vogeli (n=6) infected dogs were studied. The majority of B. c. canis infected dogs showed anemia (92%) predominantly non-regenerative (94%), while the B. c. vogeli infected dogs had a regenerative anemia (67%). Eccentrocytosis was present in 33% of the B. c. canis infections. Four of six B. c. vogeli infected dogs had erythrocytes membrane antibodies. One dog resulted uncertain and one resulted negative to FCI. In contrast, all the B. c. canis infected dogs were negative for erythrocytes membrane binding immunoglobulins detection. In addition, the mean percentages of erythrocytes binding IgG and IgM were statistically much lower in B. c. canis than in B. c. vogeli infected dogs. At the time of the diagnosis, the formation of erythrocyte membrane binding IgG and IgM by immune mechanisms appears not to be involved in B. c. canis infections while it is present in the majority of B. c. vogeli infections.

Immunomodulatory arsenal of nymphal ticks

Ticks have developed their own immunomodulatory mechanisms to inhibit the host inflammatory response. One of them involves the ability to subvert the cytokine network at the site of tick feeding by secreting cytokine binding molecules. Most studies have focused on the immunomodulatory prowess of adult female ticks. Here we describe anti-cytokine activity in salivary gland extracts (SGEs) prepared from 2-day-fed nymphs of Dermacentor reticulatus Fabricius, Ixodes ricinus L., Rhipicephalus appendiculatus Neumann and Amblyomma variegatum Fabricius. Anti-CXCL8 activity was detected in nymphs of all species. Relatively high activity against CCL2, CCL3 and CCL11 was observed in SGEs of R. appendiculatus and A. variegatum nymphs, whereas SGEs of I. ricinus nymphs showed comparatively high anti-interleukin-2 (-IL-2) and anti-IL-4 activities. These data show that nymphs, which epidemiologically are usually more important than adults as disease vectors, possess a range of anti-cytokine activities that may facilitate pathogen transmission.

Babesia canis canis and Babesia canis vogeli infections in dogs from northern Portugal

Canine babesiosis represents an important veterinary medical problem. This study describes the molecular characterization of babesial parasites detected in eight clinically suspected dogs from northern Portugal, affected by lethargy, muscle tremors, weight loss, pale mucous membranes, hyperthermia or red-coloured urine. Microscopic examination of peripheral blood smears showed large intraerythrocytic piroplasms morphologically compatible with Babesia canis in all eight animals. DNA was extracted from blood on filter paper, and a Babesia spp. infection confirmed by polymerase chain reaction (PCR) amplification of a 408bp fragment of the 18S rRNA gene. Analysis of PCR-derived sequences revealed that seven dogs were infected with B. canis canis and one with B. canis vogeli. This is the first molecular identification report of both the species B. canis and the subspecies B. canis canis and B. canis vogeli in dogs from Portugal.