Factors contributing to emergence of Ehrlichia and Anaplasma spp. as human pathogens

Detection of tick-borne pathogens in Rhipicephalus bursa ticks collected from the autochthonous Garrano breed of horses in Portugal

The Garrano is a semi-feral horse breed native to several mountains in the northern Iberian Peninsula. Despite being endangered, this unique breed of pony has managed to survive in the wild and continues to be selectively bred, highlighting their remarkable resilience and adaptability to harsh environments. Wildlife plays a critical role in the survival of tick vectors in their natural habitats and the transfer of tick-borne pathogens, as they can serve as reservoir hosts for many agents and amplifiers for these vectors. The semi-feral lifestyle of the Garrano horses makes them particularly vulnerable to exposure to numerous tick species throughout the year. Therefore, the aim of this study was to investigate the occurrence of Anaplasma, Ehrlichia, Babesia, Theileria, and spotted fever rickettsiae in the Garrano horse ticks to obtain a knowledge of circulating agents in this host population. The collected ticks (n = 455) were identified as Rhipicephalus bursa. DNA specimens were organized in pools of 5 ticks, for molecular screening. Pools PCR results confirmed the presence of Candidatus Rickettsia barbariae (n = 12 for the ompB gene, n = 11 for the ompA gene and n = 6 for the gltA gene), Babesia bigemina (n = 1), Babesia caballi (n = 3), Theileria equi (n = 15) and Theileria haneyi (n = 1).These results confirm the circulation of an emerging rickettsial spotted fever group member, Candidatus R. barbariae, in R. bursa ticks. Our findings demonstrated that Candidatus R. barbariae co-circulates with B. bigemina and T. equi, which are vectored by R. bursa. We are reporting for the first time, the detection of T. haneyi among R. bursa ticks feeding in the Garrano horses in Portugal. Surveillance studies for tick-borne infections are essential to provide information that can facilitate the implementation of preventive and control strategies.

Diversity of Ehrlichia spp., Anaplasma spp. and Neorickettsia spp. in vampire bats

Although bats (Mammalia: Chiroptera) act as natural reservoirs for many zoonotic pathogens around the world, few studies have investigated the occurrence of Anaplasmataceae agents in bats, especially vampire bats. The family Anaplasmataceae (order Rickettsiales) encompasses obligate intracellular bacteria of the genera Anaplasma, Ehrlichia, Neorickettsia, Neoehrlichia, Wolbachia, and Allocryptoplasma. The present study aimed to investigate, using molecular techniques, the presence of species of Anaplasma, Ehrlichia, and Neorickettsia in vampire bats sampled in northern Brazil. Between 2017 and 2019, spleen samples were collected from vampire bats belonging to two species, Desmodus rotundus (n = 228) from the states of Pará (n = 207), Amazonas (n = 1), Roraima (n = 18) and Amapá (n = 3), and Diaemus youngii (n = 1) from Pará. Positivity rates of 5.2% (12/229), 3% (7/229), and 10.9% (25/229) were found in PCR assays for Anaplasma spp. (16S rRNA gene), Ehrlichia spp. (dsb gene) and Neorickettsia spp. (16S rRNA gene), respectively. The present study revealed, for the first time, the occurrence of Anaplasma spp. and different genotypes of Ehrlichia spp. in vampire bats from Brazil. While phylogenetic analyses based on the dsb and ftsZ genes of Ehrlichia and 16S rRNA of Anaplasma spp. revealed phylogenetic proximity of the genotypes detected in vampire bats with Anaplasmataceae agents associated with domestic ruminants, phylogenetic inferences based on the gltA and groEL genes evidenced the occurrence of genotypes apparently exclusive to bats. Neorickettsia sp. phylogenetically associated with N. risticii was also detected in vampire bats sampled in northern Brazil.

The prevalence of selected vector-borne diseases in dromedary camels (Camelus dromedarius) in the United Arab Emirates

Vector-borne diseases (VBDs) affecting dromedary camels (Camelus dromedarius) have considerable importance in the United Arab Emirates (UAE) because of the consequences associated with production decline and economic losses. Our study aimed to determine the prevalence of selected VBDs in camels in the UAE and identify risk factors. This research is currently affected by the low number of epidemiological molecular surveys addressing this issue. Blood samples were obtained from 425 dromedary camels from different locations across the UAE. Whole genomic DNA was isolated, and PCR screening was done to detect piroplasmids (Babesia/Theileria spp.), Trypanosoma spp., and Anaplasmataceae spp. (Anaplasma, Ehrlichia, Neorickettsia and Wolbachia spp.). Amplicons were sequenced, and phylogenetic trees were constructed. Trypanosoma sequences were identified as T. brucei evansi, whereas Anaplasmataceae sequences were identified as A. platys-like. All camels were negative for Babesia/Theileria spp. (0%); however, 18 camels were positive for T. b. evansi (4%) and 52 were positive for A. platys-like (12%). Mixed infection with T. b. evansi and A. platys-like was found in one camel. Statistical analyses revealed that camels with a brown coat colour were significantly more prone to acquire the A. platys-like strain compared with those having a clearer coat. A similar finding was observed when comparing urban moving camels with desert indoor and urban indoor camels. Continuous disease surveillance is required to ensure and maintain the good health status of the camels in the UAE. Nonetheless, the risk of disease outbreak remains if the misuse of drugs continues.

An ecological and epidemiological single-season survey of Anaplasma and Ehrlichia positive ticks in Victoria Falls National Park, Zimbabwe

There is an urgent need for continued research on the ecology of tick-borne diseases in Africa. Our objective was to provide a preliminary description of the ecology and epidemiology of tick species, tick-borne pathogens, and animal hosts in Zimbabwe, focusing efforts at Victoria Falls National Park, for a single season. We tested the hypothesis that tick surveillance and pathogen screening data can be used to model associations among ticks, hosts, and pathogens. We collected ticks from domesticated animals and wildlife in Zimbabwe and screened the ticks for the presence of Anaplasma and Ehrlichia bacteria. Nearly 30% of the screened ticks were PCR-positive; 89% of tick species were PCR-positive, and 88% of animal species carried at least one PCR-positive tick. We sequenced a subset of amplicons that were similar to three Anaplasma species and three Ehrlichia species. The odds of a tick being PCR-positive increased when many ticks were collected from the host or the tick was collected from a cow (domesticated animal). Tick species shared host species more often than expected. We demonstrate that ticks in northwestern Zimbabwe present a One Health problem for nearby wildlife and humans.

Bacteria related to tick-borne pathogen assemblages in Ornithodoros cf. hasei (Acari: Argasidae) and blood of the wild mammal hosts in the Orinoquia region, Colombia

Interest in research on soft ticks has increased in recent decades, leading to valuable insight into their role as disease vectors. The use of metagenomics-based analyses have helped to elucidate ecological factors involved in pathogen, vector, and host dynamics. To understand the main bacterial assemblages present in Ornithodoros cf. hasei and its mammalian hosts, 84 ticks and 13 blood samples from bat hosts (Chiroptera) were selected, and the 16S rRNA gene V4 region was sequenced in five pools (each one related to each host-tick pairing). Bacterial taxonomic assignment analyses were performed by comparing operational taxonomic units (OTUs) shared between ticks and their host blood. This analysis showed the presence of Proteobacteria (38.8%), Enterobacteriaceae (25%), Firmicutes (12.3%), and Actinobacteria (10.9%) within blood samples, and Rickettsiaceae (39%), Firmicutes (25%), Actinobacteria (13.1%), and Proteobacteria (9%) within ticks. Species related to potentially pathogenic genera were detected in ticks, such as Borrelia sp., Bartonella tamiae, Ehrlichia sp. and Rickettsia-like endosymbiont, and the presence of these organisms was found in all analyzed bat species (Cynomops planirostris, Molossus pretiosus, Noctilio albiventris), and O. cf. hasei. About 41-48.6% of bacterial OTUs (genera and species) were shared between ticks and the blood of bat hosts. Targeted metagenomic screening techniques allowed the detection of tick-associated pathogens for O. cf. hasei and small mammals for the first time, enabling future research on many of these pathogens.

Tracking tick-borne diseases in Mongolian livestock using next generation sequencing (NGS)

The livestock industry in Mongolia accounts for 24% of national revenue, with one third of the population maintaining a pastoral lifestyle. This close connection between Mongolian population and livestock is a major concern for pathogen transfer, especially given the increase in vector-borne diseases globally. This study examines blood samples from livestock to assess the prevalence of tick-borne bacterial infections across three provinces in Mongolia (Dornogovi, Selenge, Töv). Whole blood samples from 243 livestock (cattle=38, camel=11, goat=85, horse=22, sheep=87) were analyzed with 16S metagenomics next-generation sequencing (NGS) to screen for bacterial pathogens. Positive-NGS samples for Anaplasma, Bartonella, Ehrlichia, Francisella, Leptospira, and Rickettsia were confirmed by conventional PCR and DNA sequencing. Prevalence rates of Anaplasma, Bartonella, and Ehrlichia were 57.6%, 12.8%, and 0.4%, respectively. A significant difference in the prevalence of Anaplasma spp. in livestock by province was observed, with a higher prevalence in Selenge (74.2%, p<0.001) and Töv (64.2% p = 0.006) compared to the semi-arid region of Dornogovi (39.8%). In contrast, no association was observed in Bartonella prevalence by provinces. All Anaplasma sequences (N = 139) were characterized as A. ovis. For Bartonella species characterization, phylogenetic analyses of gltA and rpoB genes identified three Bartonella species including B. bovis, B. melophagi and Candidatus B. ovis. Bartonella bovis was detected in all 22-positive cattle, while B. melophagi and Candidatus B. ovis were found in four and three sheep, respectively. This study identifies a high prevalence of tick-borne pathogens within the livestock population and to our knowledge, is the first time NGS methods have been used to explore tick-borne diseases in Mongolia. Further research is needed in Mongolia to better understand the clinical and economic burdens associated with tick-borne diseases in both livestock and pastoral herder populations.

Prevalence of Ticks Infesting Dairy Cattle and the Pathogens They Harbour in Smallholder Farms in Peri-Urban Areas of Nairobi, Kenya

This study aimed at determining the tick species infesting dairy cattle in Nairobi, Kenya, and the pathogens they harbour. While ticks are well-known vectors of major bacterial pathogens of both veterinary importance and public health importance, few studies have investigated the range of the tick species and the associated pathogens, especially present in unique dairy production systems, which compromise animal welfare, such as those in peri-urban areas. A cross-sectional study was undertaken involving 314 randomly selected dairy cattle in 109 smallholder farms. Each animal was examined for attached ticks followed by morphological tick identification at the species level. Genomic DNA was extracted from each of the ticks, and 16S rDNA gene was amplified for pathogen identification. Sequencing of the amplicons and subsequent BLASTn analysis, multiple sequence alignment, and phylogenetic reconstruction were performed to confirm the species of the pathogens. Sixty-six (21.0%) of the cattle examined had ticks. A total of 94 adult ticks were found on the cattle, and of these, 63 (67.0%), 18 (19.1%), and 13 (13.8%) were in the genera Rhipicephalus, Amblyomma, and Hyalomma, respectively. Twelve tick species in Rhipicephalus genus and two in Amblyomma and Hyalomma genera were identified. Although Rh. decoloratus was the most prevalent tick (24.5% (23/94)), the emerging Rh. microplus (6.4% (6/94)) was also identified. The DNA of Rickettsia was detected in the ticks, with Rickettsia conorii in H. rufipes and A. variegatum, and Rickettsia aeschlimannii in Rh. microplus and H. rufipes, while Ehrlichia ruminantium and E. canis were in A. variegatum. In conclusion, the study reported a wide range of tick species present in the study area including Rhipicephalus microplus, which is an emerging tick species in parts of Kenya. The ticks harboured DNA of Rickettsia and Ehrlichia, highlighting possible animal and human health concerns. Hence, effective tick control strategies remain paramount to prevent potential diseases associated with the harboured pathogens.

Challenges of Diagnosing Severe Ehrlichiosis in Orthotopic Liver Transplant Recipients

In recent solid organ transplant recipients, acute febrile illness is usually a source of grave concern and a diagnostic dilemma, especially if no response is noted after initiation of broad antimicrobial therapy. Human Monocytic Ehrlichiosis (HME) is a tick-borne illness caused by Ehrlichia chaffeensis and is not considered an opportunistic infection in immunocompromised patients such as solid organ transplant patients. Ehrlichiosis in immunocompromised patients can be life-threatening, and a strong index of suspicion is needed, especially in patients who live in endemic areas, for proper treatment initiation with doxycycline. We report a case of a 40-year-old male who received an orthotopic liver transplant six months earlier secondary to primary sclerosing cholangitis, on chronic immunosuppressive medication, who presented with complaints of sudden onset fever associated with nausea, vomiting, and diarrhea. Initial extensive infectious workup was negative and no response to empiric antimicrobials. There was suspicion for ehrlichiosis prompting empiric doxycycline use. Subsequently, E. chaffeensis polymerase chain reaction (PCR) was positive, and the antibiotic regimen was de-escalated to only doxycycline with complete resolution of his symptoms and progressive improvement in previously abnormal biochemical indices.

Vector-borne zoonotic blood parasites in wildlife from Ecuador: A report and systematic review

Background and Aim:

Ecuador is a hugely diverse country, but information on infectious diseases in local wild animals is scarce. The aim of this study was to screen the presence of blood parasites in free-ranging wild animals admitted to the Wildlife Hospital at Universidad San Francisco de Quito, from April 2012 to January 2019.

Materials and Methods:

We identified blood parasites by microscopic observation of blood smears from free-ranging wildlife species that attended the Wildlife Hospital of Universidad San Francisco de Quito (Ecuador) from April 2012 to January 2019.

Results:

The microscopic evaluations of animals as potential reservoirs for vector-borne zoonotic blood parasites revealed the presence of Anaplasma spp., Babesia spp., Ehrlichia spp., Hepatozoon spp., microfilaria, Mycoplasma spp., and Trypanosoma spp. in previously unreported wildlife species. In addition, we performed a systematic review to understand the current knowledge gaps in the context of these findings.

Conclusion:

Our data contribute to the knowledge of blood parasites in wildlife from Ecuador. Furthermore, the potential transmission of these parasites to humans and domestic animals, current anthropogenic environmental changes in the region, and the lack of information on this suggest the importance of our results and warrant further investigations on infectious diseases in animals and humans and their relationship with environmental health as key domains of the One Health concept.

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

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

Granulocytic anaplasmosis in captive ring-tailed lemur (Lemur catta) in Poland

Background

Anaplasma are obligate intracellular bacteria and aetiological agents of tick-borne diseases of both veterinary and medical interest. The genus Anaplasma comprises six species: Anaplasma marginale, Anaplasma centrale, Anaplasma ovis, Anaplasma phagocytophilum, Anaplasma bovis and Anaplasma platys. They can infect humans, carnivores, ruminants, rodents, insectivores, birds and reptiles. The aim of this study was to present the first clinical case of granulocytic anaplasmosis in a captive ring-tailed lemur in Poland.

Case presentation

A 4-year-old female lemur presented anorexia, epistaxis and tick infestation. The microscopic examination of a blood smear revealed morulae in neutrophils. Polymerase chain reaction test and sequencing of obtained PCR product confirmed infection by the GU183908 Anaplasma phagocytophilum strain. Therapeutic protocol included doxycycline (2.5 mg/kg p.o., b.i.d.) for 3 weeks and the lemur recovered within 24 h.

Conclusions

This is the first report on granulocytic anaplasmosis in a ring-tailed lemur in Europe, indicating that A. phagocytophilum infection must also be considered in differential diagnosis in this animal species, especially in individuals with thrombocytopenia associated with Ixodes ricinus parasitism.

Tick-borne pathogens, including Crimean-Congo haemorrhagic fever virus, at livestock markets and slaughterhouses in western Kenya

Vectors of emerging infectious diseases have expanded their distributional ranges in recent decades due to increased global travel, trade connectivity and climate change. Transboundary range shifts, arising from the continuous movement of humans and livestock across borders, are of particular disease control concern. Several tick-borne diseases are known to circulate between eastern Uganda and the western counties of Kenya, with one fatal case of Crimean-Congo haemorrhagic fever (CCHF) reported in 2000 in western Kenya. Recent reports of CCHF in Uganda have highlighted the risk of cross-border disease translocation and the importance of establishing inter-epidemic, early warning systems to detect possible outbreaks. We therefore carried out surveillance of tick-borne zoonotic pathogens at livestock markets and slaughterhouses in three counties of western Kenya that neighbour Uganda. Ticks and other ectoparasites were collected from livestock and identified using morphological keys. The two most frequently sampled tick species were Rhipicephalus decoloratus (35%) and Amblyomma variegatum (30%); Ctenocephalides felis fleas and Haematopinus suis lice were also present. In total, 486 ticks, lice and fleas were screened for pathogen presence using established molecular workflows incorporating high-resolution melting analysis and identified through sequencing of PCR products. We detected CCHF virus in Rh. decoloratus and Rhipicephalus sp. cattle ticks, and 82 of 96 pools of Am. variegatum were positive for Rickettsia africae. Apicomplexan protozoa and bacteria of veterinary importance, such as Theileria parva, Babesia bigemina and Anaplasma marginale, were primarily detected in rhipicephaline ticks. Our findings show the presence of several pathogens of public health and veterinary importance in ticks from livestock at livestock markets and slaughterhouses in western Kenya. Confirmation of CCHF virus, a Nairovirus that causes haemorrhagic fever with a high case fatality rate in humans, highlights the risk of under-diagnosed zoonotic diseases and calls for continuous surveillance and the development of preventative measures.

Increasing Incidence of Anaplasmosis in the United States, 2012 Through 2016

Anaplasmosis is a tick-borne disease that is primarily caused by the rickettsial bacterium Anaplasma phagocytophilum. Anaplasmosis is a febrile disease with common symptoms, including headaches, fever, and lethargy, but it can cause serious organ failure and even death if left untreated. Human infections are reported annually to the Centers for Disease Control and Prevention (CDC) through the National Notifiable Diseases Surveillance System (NNDSS). This report analyzed the cases of anaplasmosis reported by the NNDSS from 2012 to 2016. In total, there were 15,778 reported A. phagocytophilum infections, and the incidence rate was 7.27 cases per million persons per year, with the number of reported cases increasing each year. The demographic group most affected was middle-aged and elderly white males. Infections were most abundant in the coastal northeast and northern midwest regions. Our study provides useful results for a basic understanding of incidence, distribution, and severity of A. phagocytophilum infections.

Ehrlichia spp. and Anaplasma spp. in Xenarthra mammals from Brazil, with evidence of novel 'Candidatus Anaplasma spp.'

Anaplasmataceae agents are obligatory intracellular Gram-negative α-proteobacteria that are transmitted mostly by arthropod vectors. Although mammals of the Superorder Xenarthra (sloths, anteaters, and armadillos) have been implicated as reservoirs for several zoonotic agents, only few studies have sought to detect Anaplasmataceae agents in this group of mammals. This study aimed to investigate the occurrence and genetic diversity of Anaplasma spp. and Ehrlichia spp. in blood and spleen samples of free-living Xenarthra from four different states in Brazil (São Paulo, Mato Grosso do Sul, Rondônia, and Pará). Nested and conventional PCR screening assays were performed to detect the rrs and dsb genes of Anaplasma spp. and Ehrlichia spp., respectively. The assays were positive in 27.57% (91/330) of the Anaplasma spp. and 24.54% (81/330) of the Ehrlichia spp. Of the 91 positive Anaplasma spp. samples, 56.04% were positive in a conventional PCR assay targeting the 23S–5S intergenic region. Phylogenetic and distance analyses based on the rrs gene allocated Anaplasma sequences from sloths captured in Rondônia and Pará states in a single clade, which was closely related to the A. marginale, A. ovis, and A. capra clades. The sequences detected in southern anteaters from São Paulo were allocated in a clade closely related to sequences of Anaplasma spp. detected in Nasua nasua, Leopardus pardalis, and Cerdocyon thous in Brazil. These sequences were positioned close to A. odocoilei sequences. Genotype analysis corroborated previous findings and demonstrated the circulation of two distinct Anaplasma genotypes in animals from north and southeast Brazil. The first genotype was new. The second was previously detected in N. nasua in Mato Grosso do Sul state. The intergenic region analyses also demonstrated two distinct genotypes of Anaplasma. The sequences detected in Xenarthra from Pará and Rondônia states were closely related to those in A. marginale, A. ovis, and A. capra. Anaplasma spp. sequences detected in Xenarthra from São Paulo and were allocated close to those in A. phagocytophilum. The analyses based on the dsb gene grouped the Ehrlichia spp. sequences with sequences of E. canis (São Paulo, Mato Grosso do Sul, and Pará) and E. minasensis (Rondônia and Pará). The data indicate the occurrence of E. canis and E. minasensis and two possible new Candidatus species of Anaplasma spp. in free-living mammals of the Superorder Xenarthra in Brazil.

Detection of blood pathogens in camels and their associated ectoparasitic camel biting keds, Hippobosca camelina: the potential application of keds in xenodiagnosis of camel haemopathogens

Background: Major constraints to camel production include pests and diseases. In northern Kenya, little information is available about blood-borne pathogens circulating in one-humped camels ( Camelus dromedarius) or their possible transmission by the camel haematophagous ectoparasite, Hippobosca camelina, commonly known as camel ked or camel fly. This study aimed to: (i) identify the presence of potentially insect-vectored pathogens in camels and camel keds, and (ii) assess the potential utility of keds for xenodiagnosis of camel pathogens that they may not vector.

Methods: In Laisamis, northern Kenya, camel blood samples (n = 249) and camel keds (n = 117) were randomly collected from camels. All samples were screened for trypanosomal and camelpox DNA by PCR, and for Anaplasma, Ehrlichia, Brucella, Coxiella, Theileria, and Babesia by PCR coupled with high-resolution melting (PCR-HRM) analysis.

Results: In camels, we detected Trypanosoma vivax (41%), Trypanosoma evansi (1.2%), and “ Candidatus Anaplasma camelii” (68.67%). In camel keds, we also detected T. vivax (45.3%), T. evansi (2.56%), Trypanosoma melophagium (1/117) (0.4%), and “ Candidatus Anaplasma camelii” (16.24 %). Piroplasms ( Theileria spp. and Babesia spp.), Coxiella burnetii, Brucella spp., Ehrlichia spp., and camel pox were not detected in any samples.

Conclusions: This study reveals the presence of epizootic pathogens in camels from northern Kenya. Furthermore, the presence of the same pathogens in camels and in keds collected from sampled camels suggests the potential use of these flies in xenodiagnosis of haemopathogens circulating in camels.

Detection of blood pathogens in camels and their associated ectoparasitic camel biting keds, Hippobosca camelina: the potential application of keds in xenodiagnosis of camel haemopathogens

Background: Major constraints to camel production include pests and diseases. In northern Kenya, little information is available about blood-borne pathogens circulating in one-humped camels ( Camelus dromedarius) or their possible transmission by the camel haematophagous ectoparasite, Hippobosca camelina, commonly known as camel ked or camel fly. This study aimed to: (i) identify the presence of potentially insect-vectored pathogens in camels and camel keds, and (ii) assess the potential utility of keds for xenodiagnosis of camel pathogens that they may not vector. Methods: In Laisamis, northern Kenya, camel blood samples (n = 249) and camel keds (n = 117) were randomly collected from camels. All samples were screened for trypanosomal and camelpox DNA by PCR, and for Anaplasma, Ehrlichia, Brucella, Coxiella, Theileria, and Babesia by PCR coupled with high-resolution melting (PCR-HRM) analysis. Results: In camels, we detected Trypanosoma vivax (41%), Trypanosoma evansi (1.2%), and " Candidatus Anaplasma camelii" (68.67%). In camel keds, we also detected T. vivax (45.3%), T. evansi (2.56%), Trypanosoma melophagium (1/117) (0.4%), and " Candidatus Anaplasma camelii" (16.24 %). Piroplasms ( Theileria spp. and Babesia spp.), Coxiella burnetii, Brucella spp., Ehrlichia spp., and camel pox were not detected in any samples. Conclusions: This study reveals the presence of epizootic pathogens in camels from northern Kenya. Furthermore, the presence of the same pathogens in camels and in keds collected from sampled camels suggests the potential use of these flies in xenodiagnosis of haemopathogens circulating in camels.

Prevalence and Risk Factors of Antibodies to Anaplasma spp. in Chile: A Household-Based Cross-Sectional Study in Healthy Adults and Domestic Dogs

Background: Pet-related tick-borne infections constitute an emerging problem in human and veterinary medicine worldwide. In Chile, two pathogens of the Anaplasmataceae family, Anaplasma platys and Ehrlichia canis, have been identified in recent years in dogs and vectors. This epidemiological survey aimed to determine the human and canine seroprevalence of Anaplasma spp. in urban and rural areas of different regions in Chile and to analyze the factors associated with seropositivity. Methods: We performed a cross-sectional household-based study in four regions, where healthy adults and their household dogs were included. Households were chosen by double stratified random sampling in urban areas and by convenience sampling in rural areas. Anaplasma seroreactivity was determined by a commercial microimmunofluorescence assay using Anaplasma phagocytophilum antigens. A questionnaire survey was applied to assess risk factors for Anaplasma seropositivity. Results: A total of 1105 persons and 905 dogs were included. The overall seroprevalence in humans was 9.4%, ranging from 5.6% in central Chile to 13.7% in the extreme north; in dogs the overall prevalence was 44.0% and ranged from 37.2% in the northern region to 61.1% in central Chile. Risk factors for human seropositivity were lower education and external deworming of dogs, whereas canine seropositivity was associated to urban site, mixed-breed, older animals, and tick infestation. Conclusions: This cross-sectional study suggests a broad exposure of both dogs and dog owners to Anaplasma or related agents in Chile. Further epidemiological and clinical studies are necessary to understand the complete spectrum and epidemiology of tick-borne zoonotic infections in the different ecoclimatic regions of Chile.

Phylogenetic profiling for zoonotic Ehrlichia spp. from ixodid ticks in the Eastern Cape, South Africa

Ticks are obligate hematophagous parasite of vertebrate that transmit a range of pathogenic microorganisms that can cause diseases in livestock and humans. The range of tick-borne disease causative agents infecting domestic animals and humans has recently increased. Several significant zoonotic tick-borne diseases such as ehrlichiosis among others are on the increase worldwide. This study was designed to investigate the occurrence of zoonotic Ehrlichia spp. from samples collected from livestock in selected communities in the Eastern Cape Province, South Africa. Tick samples were manually collected from domesticated animals in selected homesteads. The ticks were morphologically identified to species and tested for Ehrlichia infection via polymerase chain reaction (PCR), using genus-specific disulphide bond formation protein (dsbA) gene primers. This was followed by sequence analysis of amplicons and phylogeny. Of the 1,200 ticks collected, Amblyomma hebraeum was most prevalent (n = 335; 27.9%), followed by Rhipicephalus appendiculatus (n = 274; 22.8%), Rhipicephalus decoloratus; (n = 224; 18.7%) and Rhipicephalus eversti eversti (n = 200, 16.7%). Ehrlichia DNA was detected in 19/1,200 (1.6%) of the screened DNA samples. A homology search of the generated sequences revealed a high percentage of identity between 95% and 98% with other homologous dsbA gene sequences of other Ehrlichia species in GenBank. Phylogenetic analysis showed that the obtained sequences clustered unambiguously with other Ehrlichia sequences from different geographical regions of the world. We concluded that Ehrlichial pathogens are vectored by the ticks collected from domesticated animals in the study areas, thus suggesting concern for public health, as some of the recovered pathogens are zoonotic in nature and could pose serious public health risk through human exposure to tick bites.

Does co-infection with vector-borne pathogens play a role in clinical canine leishmaniosis?

BACKGROUND

The severity of canine leishmaniosis (CanL) due to Leishmania infantum might be affected by other vector-borne organisms that mimic its clinical signs and clinicopathological abnormalities. The aim of this study was to determine co-infections with other vector-borne pathogens based on serological and molecular techniques in dogs with clinical leishmaniosis living in Spain and to associate them with clinical signs and clinicopathological abnormalities as well as disease severity.

METHODS

Sixty-one dogs with clinical leishmaniosis and 16 apparently healthy dogs were tested for Rickettsia conorii, Ehrlichia canis, Anaplasma phagocytophilum and Bartonella henselae antigens by the immunofluorescence antibody test (IFAT) and for E. canis, Anaplasma spp., Hepatozoon spp., Babesia spp. and filarioid DNA by polymerase chain reaction (PCR).

RESULTS

Among the dogs examined by IFAT, the seroprevalences were: 69% for R. conorii, 57% for E. canis, 44% for A. phagocytophilum and 37% for B. henselae; while the prevalences found by PCR were: 8% for Ehrlichia/Anaplasma, 3% for Anaplasma platys and 1% for H. canis. No other pathogen DNA was detected. Statistical association was found between dogs with clinical leishmaniosis and seroreactivity to R. conorii antigen (Fisher's exact test: P = 0.025, OR = 4.1, 95% CI = 1-17) and A. phagocytophilum antigen (Fisher's exact test: P = 0.002, OR = 14.3, 95% CI = 2-626) and being positive to more than one serological or molecular tests (co-infections) (Mann-Whitney test: U = 243, Z = -2.6, n ₁  = 14, n ₂  = 61, P = 0.01) when compared with healthy dogs. Interestingly, a statistical association was found between the presence of R. conorii, E. canis, A. phagocytophilum and B. henselae antibodies in sick dogs and some clinicopathological abnormalities such as albumin and albumin/globulin ratio decrease and increase in serum globulins. Furthermore, seroreactivity with A. phagocytophilum antigens was statistically associated with CanL clinical stages III and IV.

CONCLUSIONS

This study demonstrates that dogs with clinical leishmaniosis from Catalonia (Spain) have a higher rate of co-infections with other vector-borne pathogens when compared with healthy controls. Furthermore, positivity to some vector-borne pathogens was associated with more marked clinicopathological abnormalities as well as disease severity with CanL.

Molecular detection of Anaplasmataceae agents in Dasyprocta azarae in northeastern Brazil

Recently, the importance of wild-living rodents for maintenance of pathogens of the family Anaplasmataceae in the environment was investigated. These mammals play a role as reservoirs for these pathogens and act as hosts for the immature stages of tick vectors. The aim of the present study was to investigate the prevalence of Ehrlichia sp. and Anaplasma sp. in 24 specimens of Azara's agouti (Dasyprocta azarae) that had been trapped in the Itapiracó Environmental Reserve, in São Luís, Maranhão, northeastern Brazil, using molecular methods. Four animals (16.7%) were positive for Ehrlichia spp. in nested PCR assays based on the 16S rRNA gene. In a phylogenetic analysis based on the 16S rRNA gene, using the maximum likelihood method and the GTRGAMMA+I evolutionary model, Ehrlichia sp. genotypes detected in Azara's agoutis were found to be closely related to E. canis and to genotypes relating to E. canis that had previously been detected in free-living animals in Brazil. The present work showed the first molecular detection of Ehrlichia sp. in Azara's agoutis in Brazil.

Tick-borne bacteria and protozoa detected in ticks collected from domestic animals and wildlife in central and southern Portugal

Ticks are vectors of many human and animal pathogens. The aim of this study was to screen bacteria and protozoa from ticks infesting domestic animals and wildlife collected in central and southern Portugal. A total of 593 ticks, comprising 465 (78.4%) adults, 122 (20.6%) nymphs, and six (1.0%) larvae, were collected from 283 hosts of 25 different species (4 domestic and 21 wild). Overall, the analysis of DNA extracts prepared from ticks collected from hosts of 11 different species in the districts of Castelo Branco, Portalegre, Lisboa, Setúbal, Beja and Faro, revealed the presence of genomic sequences from Anaplasma sp., A. ovis, Babesia sp., relapsing fever-like Borrelia sp., Ehrlichia spp., Rickettsia aeschlimannii, Ri. helvetica, Ri. massiliae, Ri. raoultii, Ri. slovaca, Candidatus Ri. barbariae, Theileria annulata and T. ovis, in specimens of Dermacentor marginatus, Hyalomma lusitanicum, Hy. marginatum, Rhipicephalus bursa and Rh. sanguineus sensu lato. The obtained results suggest the circulation of a wide variety of infectious agents, some of zoonotic concern, in hard ticks from Portugal. Further studies should be conducted to better characterize (both genetically and phenotypically) the putative novel microorganisms detected, both in what regards their potential pathogenity towards vertebrates, and to assist the implementation of effective control strategies for the management of ticks and human and animal tick-borne pathogens.

Assessment of a quantitative 5' nuclease real-time polymerase chain reaction using groEL gene for Ehrlichia and Anaplasma species in rodents in Brazil

New genotypes of Anaplasmataceae agents have been detected in wild carnivores, birds and deer in Brazil. The present work aimed to investigate the presence of Ehrlichia and Anaplasma species in rodents sampled in Brazil. Additionally, a newly designed quantitative 5' nuclease real-time multiplex PCR for Ehrlichia and Anaplasma spp. detection based on groEL gene amplification was designed, showing high specificity and sensitivity (10 groEL fragment copy/μL). Between 2000 and 2011, different rodent species [n=60] were trapped in 5 Brazilian biomes. Among 458 rodent spleen samples, 0.4% (2/458) and 2.4% (11/458) were positive for Ehrlichia and Anaplasma spp., respectively. Of 458 samples, 2.0% (9/458) and 1.1% (5/458) were positive for Anaplasma sp. and Ehrlichia sp., respectively, using conventional 16S rRNA PCR assays. Maximum Likelihood phylogenetic analyse based on a small region of 16S rRNA genes positioned the Anaplasma genotypes in rodents near Anaplasma phagocytophilum or Anaplasma marginale and Anaplasma odocoilei isolates. Ehrlichia genotypes were closely related to E. canis. There was a low occurrence of Anaplasma and Ehrlichia in wild and synanthropic rodents in Brazil, suggesting the circulation of new genotypes of these agents in rodents in the studied areas.

Anaplasma phagocytophilum in questing Ixodes ricinus ticks in southwestern Finland

Anaplasma phagocytophilum is the causative agent of an emerging tick-borne disease, human granulocytic anaplasmosis. While the bacterium has been reported from questing ticks in neighboring Sweden, Norway and Russia, the few surveys regarding questing ticks in Finland have thus far been negative. In the current study, the prevalence of A. phagocytophilum in Ixodes ricinus populations was evaluated in several study localities around southwestern Finland during 2013-2014. Some of these populations were previously screened and found negative for A. phagocytophilum in 2000. A total of 3158 I. ricinus collected by blanket dragging were screened for Anaplasma spp. using qPCR. Anaplasma were detected in 9.2% of adult ticks (n = 87) and 3.1% of nymphs (n = 979). All larval samples were negative for infection. All Anaplasma-positive samples were identified as A. phagocytophilum by sequencing. This is, to the best of our knowledge, the first report of the pathogen from questing ticks in Finland. Furthermore, the pathogen was detected from several localities found negative during the previous screening 13 years earlier.

Anaplasma marginale and A. phagocytophilum in cattle in Tunisia

Background

Tick-borne diseases caused by Anaplasma species put serious constraints on the health and production of domestic cattle in tropical and sub-tropical regions. After recovering from a primary infection, cattle typically become persistent carriers of pathogens and play a critical role in the epidemiology of the disease, acting as reservoirs of the Anaplasma spp.

Methods

In this study a duplex PCR assay was used for the simultaneous detection of Anaplasma marginale and Anaplasma phagocytophilum in cattle using two primer pairs targeting msp4 and msp2 genes, respectively. We used this method to analyze DNA preparations derived from 328 blood cattle samples that were collected from 80 farms distributed among Tunisia’s four bioclimatic zones.

Results

The prevalence of the A. marginale infection (24.7 %) was significantly higher and more widespread (in all bioclimatic areas) than that of A. phagocytophilum (0.6 %), which was found in a mixed infection with A. marginale.

Conclusions

The duplex PCR assay used proved to be a rapid, specific and inexpensive mean for the simultaneous detection of Anaplasma marginale and Anaplasma phagocytophilum in cattle blood. It allowed us to report the identification of A. phagocytophilum for the first time in cattle in Tunisia and confirm the presence of A. marginale in cattle from several geographical areas of the country. Further epidemiological studies undertaken using this assay will help improve the surveillance of the associated diseases in the regions where they are endemic.

Assessment of a quantitative 5' nuclease real-time polymerase chain reaction using the nicotinamide adenine dinucleotide dehydrogenase gamma subunit (nuoG) for Bartonella species in domiciled and stray cats in Brazil

OBJECTIVES

The objective of this study was to develop a quantitative 5' nuclease real-time polymerase chain reaction (PCR) assay to diagnose infections caused by Bartonella species.

METHODS

Between January and April 2013 whole blood samples were collected by convenience from 151 cats (86 domiciled and 65 stray cats). The feline blood samples were subjected to a novel quantitative 5' nuclease real-time PCR (qPCR) for Bartonella species targeting the nictonamide adenine dinucleotide dehydrogenase gamma subunit (nuoG) and conventional PCR assays targeting intergenic transcribed spacer, ribC, gltA, pap31 and rpoB, followed by sequencing and basic local alignment search tool analysis.

RESULTS

The qPCR assay detected as few as 10 copies of plasmid per reaction. Forty-six (54.4% domiciled and 45.6% stray cats) of 151 sampled cats showed positive results in nuoG qPCR for Bartonella species. The absolute quantification of nuoG Bartonella DNA in sampled cats ranged from 1.1 × 10(4) to 1.3 × 10(4). Eighteen (39.1%) of 46 positive samples in the qPCR were also positive in conventional PCR assays. The sequencing confirmed that Bartonella henselae and Bartonella clarridgeiae circulate in cats in midwestern Brazil.

CONCLUSIONS AND RELEVANCE

The present work provides details of a novel qPCR assay to diagnose infections caused by Bartonella species.

Molecular detection of tick-borne bacteria and protozoa in cervids and wild boars from Portugal

Background

Wildlife can act as reservoir of different tick-borne pathogens, such as bacteria, parasites and viruses. The aim of the present study was to assess the presence of tick-borne bacteria and protozoa with veterinary and zoonotic importance in cervids and wild boars from the Centre and South of Portugal.

Methods

One hundred and forty one blood samples from free-ranging ungulates including 73 red deer (Cervus elaphus), 65 wild boars (Sus scrofa) and three fallow deer (Dama dama) were tested for the presence of Anaplasma marginale/A. ovis, A. phagocytophilum, Anaplasma/Ehrlichia spp., Babesia/Theileria spp., Borrelia burgdorferi (sensu lato) (s.l.), and Rickettsia spp. DNA by PCR.

Results

Anaplasma spp. DNA was detected in 33 (43.4 %) cervids (31 red deer and two fallow deer) and in two (3.1 %) wild boars while Theileria spp. were found in 34 (44.7 %) cervids (32 red deer and two fallow deer) and in three (4.6 %) wild boar blood samples. Sequence analysis of msp4 sequences identified A. marginale, A. ovis, while the analysis of rDNA sequence data disclosed the presence of A. platys and A. phagocytophilum and T. capreoli and Theileria sp. OT3. Anaplasma spp./Theileria spp. mixed infections were found in 17 cervids (22.4 %) and in two wild boars (3.1 %). All samples were negative for Babesia sp., B. burgdorferi (s.l.), Ehrlichia sp. or Rickettsia sp.

Conclusions

This is the first detection of Anaplasma marginale, A. ovis, A. phagocytophilum, A. platys, Theileria capreoli and Theileria sp. OT3 in cervids and wild boars from Portugal. Further studies concerning the potential pathogenicity of the different species of  Anaplasma and Theileria infecting wild ungulates, the identification of their vector range, and their putative infectivity to domestic livestock and humans should be undertaken.

Multiple Pathogens Including Potential New Species in Tick Vectors in Côte d'Ivoire

BACKGROUND

Our study aimed to assess the presence of different pathogens in ticks collected in two regions in Côte d'Ivoire.

METHODOLOGY/PRINCIPAL FINDINGS

Real-time PCR and standard PCR assays coupled to sequencing were used. Three hundred and seventy eight (378) ticks (170 Amblyomma variegatum, 161 Rhipicepalus microplus, 3 Rhipicephalus senegalensis, 27 Hyalomma truncatum, 16 Hyalomma marginatum rufipes, and 1 Hyalomma impressum) were identified and analyzed. We identified as pathogenic bacteria, Rickettsia africae in Am. variegatum (90%), Rh. microplus (10%) and Hyalomma spp. (9%), Rickettsia aeschlimannii in Hyalomma spp. (23%), Rickettsia massiliae in Rh. senegalensis (33%) as well as Coxiella burnetii in 0.2%, Borrelia sp. in 0.2%, Anaplasma centrale in 0.2%, Anaplasma marginale in 0.5%, and Ehrlichia ruminantium in 0.5% of all ticks. Potential new species of Borrelia, Anaplasma, and Wolbachia were detected. Candidatus Borrelia africana and Candidatus Borrelia ivorensis (detected in three ticks) are phylogenetically distant from both the relapsing fever group and Lyme disease group borreliae; both were detected in Am. variegatum. Four new genotypes of bacteria from the Anaplasmataceae family were identified, namely Candidatus Anaplasma ivorensis (detected in three ticks), Candidatus Ehrlichia urmitei (in nine ticks), Candidatus Ehrlichia rustica (in four ticks), and Candidatus Wolbachia ivorensis (in one tick).

CONCLUSIONS/SIGNIFICANCE

For the first time, we demonstrate the presence of different pathogens such as R. aeschlimannii, C. burnetii, Borrelia sp., A. centrale, A. marginale, and E. ruminantium in ticks in Côte d'Ivoire as well as potential new species of unknown pathogenicity.

Application of Nanotrap technology for high sensitivity measurement of urinary outer surface protein A carboxyl-terminus domain in early stage Lyme borreliosis

OBJECTIVES

Prompt antibiotic treatment of early stage Lyme borreliosis (LB) prevents progression to severe multisystem disease. There is a clinical need to improve the diagnostic specificity of early stage Lyme assays in the period prior to the mounting of a robust serology response. Using a novel analyte harvesting nanotechnology, Nanotrap particles, we evaluated urinary Borrelia Outer surface protein A (OspA) C-terminus peptide in early stage LB before and after treatment, and in patients suspected of late stage disseminated LB.

METHOD

We employed Nanotrap particles to concentrate urinary OspA and used a highly specific anti-OspA monoclonal antibody (mAb) as a detector of the C-terminus peptides. We mapped the mAb epitope to a narrow specific OspA C-terminal domain OspA236-239 conserved across infectious Borrelia species but with no homology to human proteins and no cross-reactivity with relevant viral and non-Borrelia bacterial proteins. 268 urine samples from patients being evaluated for all categories of LB were collected in a LB endemic area. The urinary OspA assay, blinded to outcome, utilized Nanotrap particle pre-processing, western blotting to evaluate the OspA molecular size, and OspA peptide competition for confirmation.

RESULTS

OspA test characteristics: sensitivity 1.7 pg/mL (lowest limit of detection), % coefficient of variation (CV) = 8 %, dynamic range 1.7-30 pg/mL. Pre-treatment, 24/24 newly diagnosed patients with an erythema migrans (EM) rash were positive for urinary OspA while false positives for asymptomatic patients were 0/117 (Chi squared p < 10(-6)). For 10 patients who exhibited persistence of the EM rash during the course of antibiotic therapy, 10/10 were positive for urinary OspA. Urinary OspA of 8/8 patients switched from detectable to undetectable following symptom resolution post-treatment. Specificity of the urinary OspA test for the clinical symptoms was 40/40. Specificity of the urinary OspA antigen test for later serology outcome was 87.5 % (21 urinary OspA positive/24 serology positive, Chi squared p = 4.072e(-15)). 41 of 100 patients under surveillance for persistent LB in an endemic area were positive for urinary OspA protein.

CONCLUSIONS

OspA urinary shedding was strongly linked to concurrent active symptoms (e.g. EM rash and arthritis), while resolution of these symptoms after therapy correlated with urinary conversion to OspA negative.

Molecular detection of novel Anaplasmataceae closely related to Anaplasma platys and Ehrlichia canis in the dromedary camel (Camelus dromedarius)

Serological surveys have confirmed Anaplasma marginale and Anaplasma phagocytophilum infections in dromedary camels, but molecular surveys and genetic characterisation of camel-associated Anaplasma species are lacking. In this study, we detected tick-borne Anaplasmataceae in 30 of 100 (30%) healthy dromedary camels screened using a combined 16S rRNA-groEL PCR-sequencing approach. Nucleotide sequencing confirmed Anaplasmataceae genome presence in 28 of the 33 16S rRNA PCR-positive samples, with two additional positive samples, for which 16S rRNA sequence data were ambiguous, being identified by groEL gene characterisation. Phylogenetic analyses of a 1289 nt segment of the 16S rRNA gene confirmed the presence of a unique Ehrlichia lineage and a discrete Anaplasma lineage, comprising three variants, occurring at an overall prevalence of 4% and 26%, respectively. Genetic characterisation of an aligned 559 nt groEL gene region revealed the camel-associated Anaplasma and Ehrlichia lineages to be novel and most closely related to Anaplasma platys and Ehrlichia canis. Based on the confirmed monophyly, minimum pairwise genetic distances between each novel lineage and its closest sister taxon, and the inability to isolate the bacteria, we propose that Candidatus status be assigned to each. This first genetic characterisation of Anaplasmataceae from naturally infected, asymptomatic dromedary camels in Saudi Arabia confirms the presence of two novel lineages that are phylogenetically linked to two pathogenic canid species of increasing zoonotic concern.

Bacterial and protozoal agents of canine vector-borne diseases in the blood of domestic and stray dogs from southern Portugal

Background

The so-called canine vector-borne diseases (CVBD) are caused by a wide range of pathogens transmitted by arthropods. In addition to their veterinary importance, many of these canine vector-borne pathogens can also affect the human population due to their zoonotic potential, a situation that requires a One Health approach. As the prevalence of vector-borne pathogens in cats from southern Portugal has been recently evaluated, the aim of the present study was to assess if the same agents were present in dogs living in the same area, and to assess positivity-associated risk factors.

Methods

One thousand and ten dogs (521 domestic and 489 stray) from veterinary medical centres and animal shelters in southern Portugal were enrolled. Anaplasma spp./Ehrlichia spp., Bartonella spp., Borrelia burgdorferi sensu lato, Babesia spp., Hepatozoon spp. and Leishmania infantum infections were evaluated by polymerase chain reaction (PCR) assays in blood samples.

Results

Sixty-eight (6.7%) dogs were PCR-positive to at least one of the tested CVBD agent species, genera or complex, including one dog found positive to two different genera. Nineteen (1.9%) dogs were positive to Anaplasma spp./Ehrlichia spp., eight (0.8%) to B. burgdorferi s.l., 31 (3.1%) to Hepatozoon spp. and 11 (1.1%) to L. infantum. Anaplasma platys, Ehrlichia canis, B. burgdorferis.l. and Hepatozoon canis were identified by DNA sequencing, including one animal confirmed with both A. platys and H. canis. Furthermore, Wolbachia spp. was amplified in blood from four dogs. None of the tested dogs was positive by PCR for Bartonella spp. or Babesia spp.

Conclusions

The molecular identification of CVBD agents in southern Portugal, some of them with zoonotic concern, reinforces the importance to alert the veterinary community, owners and public health authorities to prevent the risk of transmission of vector-borne pathogens among dogs and to other vertebrate hosts including humans. The prevalence of the selected pathogens was lower than that previously found in cats from the same region, probably because veterinarians and owners are more aware of them in the canine population and control measures are used more often.

Ixodes ricinus and Its Transmitted Pathogens in Urban and Peri-Urban Areas in Europe: New Hazards and Relevance for Public Health

Tick-borne diseases represent major public and animal health issues worldwide. Ixodes ricinus, primarily associated with deciduous and mixed forests, is the principal vector of causative agents of viral, bacterial, and protozoan zoonotic diseases in Europe. Recently, abundant tick populations have been observed in European urban green areas, which are of public health relevance due to the exposure of humans and domesticated animals to potentially infected ticks. In urban habitats, small and medium-sized mammals, birds, companion animals (dogs and cats), and larger mammals (roe deer and wild boar) play a role in maintenance of tick populations and as reservoirs of tick-borne pathogens. Presence of ticks infected with tick-borne encephalitis virus and high prevalence of ticks infected with Borrelia burgdorferi s.l., causing Lyme borreliosis, have been reported from urbanized areas in Europe. Emerging pathogens, including bacteria of the order Rickettsiales (Anaplasma phagocytophilum, "Candidatus Neoehrlichia mikurensis," Rickettsia helvetica, and R. monacensis), Borrelia miyamotoi, and protozoans (Babesia divergens, B. venatorum, and B. microti) have also been detected in urban tick populations. Understanding the ecology of ticks and their associations with hosts in a European urbanized environment is crucial to quantify parameters necessary for risk pre-assessment and identification of public health strategies for control and prevention of tick-borne diseases.

MODERN APPROACHES TO LABORATORY DIAGNOSIS OF RICKETTSIAL DISEASES

Abstract. We present a concise review of contemporary laboratory methods for diagnosis of rickettsioses with special emphasis on diseases known in Russian Federation. Classic and emerging rickettsioses are transmitted by a diverse and expanding group of arthropod vectors including ticks, fleas, lice and mites. While epidemiological and clinical clues can provide information important for initial suspicion of rickettsial infection, sensitive and specific laboratory methods are necessary for providing probable or confirmed diagnosis of the rickettsial infection. Accurate and rapid confirmation of rickettsial infection is important for ensuring proper clinical care and prompt initiation of antibiotic therapy. Correct identification of the etiology of rickettsial diseases is also important for early identification of clustered cases, novel foci of infections, and for timely initiation of public health responses to these potentially fatal infections.

First report of Anaplasma phagocytophilum and Babesia microti in rodents in Finland

Tick-borne diseases pose an increasingly important public health problem in Europe. Rodents are the reservoir host for many tick-transmitted pathogens, including Anaplasma phagocytophilum and Babesia microti, which can cause human granulocytic anaplasmosis and babesiosis, respectively. To estimate the presence of these pathogens in rodents in Finland, we examined blood samples from 151 bank voles (Myodes glareolus) and demonstrate, for the first time, that A. phagocytophilum and B. microti commonly infect bank voles (in 22% and 40% of animals, respectively) in Finland. Sequence analysis of a fragment of 18S rRNA showed that the B. microti strain isolated was identical to the Munich strain, which is considered to be nonzoonotic. The A. phagocytophilum strain (based on a fragment of the msp4 gene) was identical to one found earlier in rodents in the United Kingdom that is transmitted by the tick Ixodes trianguliceps, all the life stages of which feed on small mammals. The infection probability of B. microti in the bank voles was the greater the older the individual was, and males were more often infected than females. A. phagocytophilum infection probability first increased and then decreased with the age of individual without any difference between sexes. While these pathogens presumably pose a limited zoonotic risk to humans in Finland, they might have important interactions with other rodent pathogens and therefore affect infection dynamics of, for example, zoonotic pathogens.

Ixodes ricinus and Its Transmitted Pathogens in Urban and Peri-Urban Areas in Europe: New Hazards and Relevance for Public Health

Tick-borne diseases represent major public and animal health issues worldwide. Ixodes ricinus, primarily associated with deciduous and mixed forests, is the principal vector of causative agents of viral, bacterial, and protozoan zoonotic diseases in Europe. Recently, abundant tick populations have been observed in European urban green areas, which are of public health relevance due to the exposure of humans and domesticated animals to potentially infected ticks. In urban habitats, small and medium-sized mammals, birds, companion animals (dogs and cats), and larger mammals (roe deer and wild boar) play a role in maintenance of tick populations and as reservoirs of tick-borne pathogens. Presence of ticks infected with tick-borne encephalitis virus and high prevalence of ticks infected with Borrelia burgdorferi s.l., causing Lyme borreliosis, have been reported from urbanized areas in Europe. Emerging pathogens, including bacteria of the order Rickettsiales (Anaplasma phagocytophilum, "Candidatus Neoehrlichia mikurensis," Rickettsia helvetica, and R. monacensis), Borrelia miyamotoi, and protozoans (Babesia divergens, B. venatorum, and B. microti) have also been detected in urban tick populations. Understanding the ecology of ticks and their associations with hosts in a European urbanized environment is crucial to quantify parameters necessary for risk pre-assessment and identification of public health strategies for control and prevention of tick-borne diseases.

Ixodes ricinus abundance and its infection with the tick-borne pathogens in urban and suburban areas of Eastern Slovakia

Background

Raising abundance of ticks and tick-borne diseases in Europe is the result of multiple factors including climate changes and human activities. Herein, we investigated the presence and seasonal activity of Ixodes ricinus ticks from 10 urban and suburban sites in two different geographical areas of southeastern and northeastern Slovakia during 2008–2010. Our aim was to study the abundance of ticks in correlation with the environmental factors and their infection with Borrelia burgdorferi sensu lato, Anaplasma phagocytophilum and Neoehrlichia mikurensis.

Methods

Questing I. ricinus ticks were collected from ten urban and suburban sites in Eastern Slovakia. A total of 670 ticks were further analysed for the presence of B. burgdorferi s.l., A. phagocytophilum and N. mikurensis by molecular methods. Tick site and environmental relations were analysed using General Linear Models (LM). The differences between the number of Lyme borreliosis cases between the Košice and Bardejov regions during a ten-year period were tested by Wilcoxon matched pairs test.

Results

In total, 2921 (1913 nymphs, 1008 adults) I. ricinus ticks were collected from 10 study sites during the main questing season. Tick activity and relative abundance differed between locations and months. Temperature and humidity were the main factors affecting the tick abundance and questing activity. Out of 670 examined ticks, 10.15% were infected with spirochetes from B. burgdorferi s.l. complex (represented by B. afzelii, B. garinii, B.valaisiana and B. burgdorferi s.s.), 2.69% with the A. phagocytophilum and 2.39% with N. mikurensis. The number of Lyme borreliosis cases per 100,000 inhabitants in the Bardejov region was significantly higher than in the Košice region.

Conclusions

Our data indicate that the risk of infection with tick-borne pathogens in Eastern Slovakia is common since 15.2% of ticks were infected at least with one of the tested microorganisms. Even though the abundance of ticks was affected by the microclimatic conditions and the prevalence of pathogens differed between the habitats, the infection risk for humans is also affected by human activities leading to an increased contact with infected ticks.

Prevalence of Theileria equi, Babesia caballi, and Anaplasma phagocytophilum in horses from the north of Portugal

Piroplasmid protozoa Theileria equi and Babesia caballi and zoonotic rickettsial bacterium Anaplasma phagocytophilum are important agents of equine vector-borne diseases (EVBD). This study aimed at investigating the prevalence of infections with or exposure to these pathogens in horses from the north of Portugal. Blood was randomly collected from 162 horses, living in 72 different stables, to prepare Giemsa-stained slide smears. Additionally, plasma samples were tested for antibodies to T. equi and B. caballi by two competitive enzyme-linked immunosorbent assays and to A. phagocytophilum by an indirect fluorescence antibody test. Five horses were positive to T. equi by microscopy (3.1 %), three to B. caballi (1.9 %), and none to A. phagocytophilum with no horse simultaneously positive for the two piroplasms. Clinically suspect animals had a significantly higher positivity to T. equi by microscopy in comparison with the nonsuspect ones (21.4 vs. 1.4 %). Twenty-nine horses were seropositive to T. equi (17.9 %), 18 to B. caballi (11.1 %), and 21 to A. phagocytophilum (13.0 %). Combined serology and microscopy positive results to T. equi and B. caballi were 19.1 and 11.7 %, respectively, with 33.3 % of the horses found positive to at least one agent. Forty horses were positive to single agents and 14 to more than one agent. An outdoor or mixed outdoor/indoor type of housing was found to be a risk factor for the combined positivity to T. equi. Infections with T. equi, B. caballi, and A. phagocytophilum are endemic in the north of Portugal. In addition to the treatment of positive horses, preventive measures should be put in practice to reduce exposure to and infection with agents of EVBD.

Emergence of human granulocytic anaplasmosis in France

In France, only one case of tick-borne human granulocytic anaplasmosis has been described in the literature (in 2003). Here, we report 5 new human cases of Anaplasma phagocytophilum infection from north-eastern France diagnosed in our laboratory in south-eastern France by serology and molecular biology. This increase is directly related to more physician interest in this disease and the implementation of a new PCR tool.

Babesia spp. and Anaplasma phagocytophilum in questing ticks, ticks parasitizing rodents and the parasitized rodents--analyzing the host-pathogen-vector interface in a metropolitan area

Background

The aims of this study were to evaluate the host-tick-pathogen interface of Babesia spp. and Anaplasma phagocytophilum in restored areas in both questing and host-attached Ixodes ricinus and Dermacentor reticulatus and their small mammalian hosts.

Methods

Questing ticks were collected from 5 sites within the city of Leipzig, Germany, in 2009. Small mammals were trapped at 3 of the 5 sites during 2010 and 2011. DNA extracts of questing and host-attached I. ricinus and D. reticulatus and of several tissue types of small mammals (the majority bank voles and yellow-necked mice), were investigated by PCR followed by sequencing for the occurrence of DNA of Babesia spp. and by real-time PCR for A. phagocytophilum. A selected number of samples positive for A. phagocytophilum were further investigated for variants of the partial 16S rRNA gene. Co-infection with Rickettsia spp. in the questing ticks was additionally investigated.

Results

4.1% of questing I. ricinus ticks, but no D. reticulatus, were positive for Babesia sp. and 8.7% of I. ricinus for A. phagocytophilum. Sequencing revealed B. microti, B. capreoli and Babesia spp. EU1 in Leipzig and sequence analysis of the partial 16S RNA gene of A. phagocytophilum revealed variants either rarely reported in human cases or associated with cervid hosts. The statistical analysis revealed significantly less ticks infected with A. phagocytophilum in a city park in Leipzig as compared to the other sampling sites. A. phagocytophilum-DNA was detected in 2 bank voles, DNA of B. microti in 1 striped field-mouse and of Babesia sp. EU1 in the skin tissue of a mole. Co-infections were detected.

Conclusion

Our results show the involvement of small mammals in the natural endemic cycles of tick-borne pathogens. A more thorough understanding of the interactions of ticks, pathogens and hosts is the essential basis for effective preventive control measures.

Serological cross-reactivity between Anaplasma marginale and an Ehrlichia species in naturally and experimentally infected cattle

Seroconversion and cross-reactivity in cattle infected with Anaplasma marginale or a recently described Ehrlichia species (BOV2010 from British Columbia, Canada) were investigated. The study used 76 samples from 20 animals, a commercially available competitive enzyme-linked immunosorbent assay (cELISA) for bovine anaplasmosis, and an indirect fluorescent antibody test (IFAT). Blood smear examination and/or polymerase chain reaction assay were performed to confirm or rule out the presence of Anaplasma or Ehrlichia. Samples comprised 3 groups. Group 1 consisted of 24 samples from 9 cattle naturally infected with Ehrlichia sp. BOV2010. Group 2 had 13 samples from 3 A. marginale-infected cattle from Manitoba, Canada. Group 3 had 39 samples, consisting of 26 from 5 calves experimentally infected with Ehrlichia sp. BOV2010, 10 from 2 calves experimentally infected with A. marginale from cattle (Manitoba) or bison (Saskatchewan), and 3 from an uninfected calf. All samples from cattle naturally or experimentally infected with Ehrlichia sp. BOV2010 or A. marginale were seropositive for A. marginale by both cELISA and IFAT, except 3 calves euthanized at 28 and 33 days post-inoculation (DPI) that did not seroconvert. Antibodies were detected in 2 experimental animals inoculated with Ehrlichia sp. BOV2010, as early as 28 and 33 DPI by the cELISA and IFAT, respectively, and by 42 DPI for both tests. The current study demonstrates that the specificity of the recombinant major surface protein 5 (MSP5) antigen is not restricted to Anaplasma spp., which reduces the utility of the test for serological diagnosis of bovine anaplasmosis in regions where Ehrlichia sp. BOV2010-infected cattle might exist.

Prevalence of Anaplasma phagocytophilum in Ixodes ricinus in Bavarian public parks, Germany

Previous studies have shown that public parks provide extraordinary habitats for ticks and tick-borne pathogens. Therefore, the aim of this study was to investigate the tick abundance (ticks/100 m(2)) in urban areas and the prevalence of Anaplasma phagocytophilum. Collection of ticks was performed by the flagging method in selected Bavarian public parks in a 2-year survey. DNA from 30 ticks of each developmental stage, sampling site and month was extracted and screened by specific real-time PCR for A. phagocytophilum. Selected positive samples were further genetically differentiated by nested PCR, targeting the 16S rRNA gene. A total of 13,403 Ixodes ricinus were collected with an average tick abundance of 15-53 ticks/100 m(2) in 2009 and 15-35 ticks/100 m(2) in 2010, depending on the sampling site. DNA of A. phagocytophilum was detected in 11.6% (n=146) and 8.5% (n=50) of adult females, 13.3% (n=164) and 9.2% (n=51) of adult males as well as 5% (n=60) and 3.9% (n=29) of nymphs for 2009 (n=3685) and 2010 (n=1884), respectively. 16S rRNA gene analysis revealed 6 different genetic variants, 2 of which were 100% identical to known sequences in humans. The results give strong evidence that the occurrence of A. phagocytophilum in I. ricinus is highly variable in different habitat types due to geographical, climatic, and biological factors as well as different genetic variants of A. phagocytophilum circulated in ticks with a noticeable habitat and host tropism.

Identification of Anaplasma phagocytophilum in tick populations in Estonia, the European part of Russia and Belarus

Anaplasma phagocytophilum is associated with diseases of goats, sheep, cattle, dogs and horses. In the beginning of the 1990s it was identified as a human pathogen, causing human granulocytic anaplasmosis (HGA) in the USA, Europe and the far east of Russia. A. phagocytophilum is maintained in nature in an enzootic cycle including ticks as the main vector and a wide range of mammalian species as reservoirs. Ixodes ricinus and I. persulcatus ticks were collected in Estonia, Belarus and the European part of Russia and screened for the presence of A. phagocytophilum by real-time PCR. Positive samples were found only among I. ricinus, in 13.4% in the European part of Russia, 4.2% in Belarus, 1.7% in mainland Estonia and 2.6% on Saaremaa Island. Positive samples were sequenced for partial 16S rRNA, groESL and ankA genes and phylogenetic analyses were performed. The results showed that A. phagocytophilum circulating in Eastern Europe belongs to different groESL lineages and 16S rRNA gene variants and also consists of variable numbers of repetitive elements within the ankA gene.

Occurrence of Babesia spp., Rickettsia spp. and Bartonella spp. in Ixodes ricinus in Bavarian public parks, Germany

Background

Only limited information is available about the occurrence of ticks and tick-borne pathogens in public parks, which are areas strongly influenced by human beings. For this reason, Ixodes ricinus were collected in public parks of different Bavarian cities in a 2-year survey (2009 and 2010) and screened for DNA of Babesia spp., Rickettsia spp. and Bartonella spp. by PCR. Species identification was performed by sequence analysis and alignment with existing sequences in GenBank. Additionally, coinfections with Anaplasma phagocytophilum were investigated.

Results

The following prevalences were detected: Babesia spp.: 0.4% (n = 17, including one pool of two larvae) in 2009 and 0.5 to 0.7% (n = 11, including one pool of five larvae) in 2010; Rickettsia spp.: 6.4 to 7.7% (n = 285, including 16 pools of 76 larvae) in 2009. DNA of Bartonella spp. in I. ricinus in Bavarian public parks could not be identified. Sequence analysis revealed the following species: Babesia sp. EU1 (n = 25), B. divergens (n = 1), B. divergens/capreoli (n = 1), B. gibsoni-like (n = 1), R. helvetica (n = 272), R. monacensis IrR/Munich (n = 12) and unspecified R. monacensis (n = 1). The majority of coinfections were R. helvetica with A. phagocytophilum (n = 27), but coinfections between Babesia spp. and A. phagocytophilum, or Babesia spp. and R. helvetica were also detected.

Conclusions

I. ricinus ticks in urban areas of Germany harbor several tick-borne pathogens and coinfections were also observed. Public parks are of particularly great interest regarding the epidemiology of tick-borne pathogens, because of differences in both the prevalence of pathogens in ticks as well as a varying species arrangement when compared to woodland areas. The record of DNA of a Babesia gibsoni-like pathogen detected in I. ricinus suggests that I. ricinus may harbor and transmit more Babesia spp. than previously known. Because of their high recreational value for human beings, urban green areas are likely to remain in the research focus on public health issues.

Small risk of developing symptomatic tick-borne diseases following a tick bite in The Netherlands

Background

In The Netherlands, the incidence of Lyme borreliosis is on the rise. Besides its causative agent, Borrelia burgdorferi s.l., other potential pathogens like Rickettsia, Babesia and Ehrlichia species are present in Ixodes ricinus ticks. The risk of disease associated with these microorganisms after tick-bites remains, however, largely unclear. A prospective study was performed to investigate how many persons with tick-bites develop localized or systemic symptoms and whether these are associated with tick-borne microorganisms.

Results

In total, 297 Ixodes ricinus ticks were collected from 246 study participants who consulted a general practitioner on the island of Ameland for tick bites. Ticks were subjected to PCR to detect DNA of Borrelia burgdorferi s.l., Rickettsia spp., Babesia spp. or Ehrlichia/Anaplasma spp.. Sixteen percent of the collected ticks were positive for Borrelia burgdorferi s.l., 19% for Rickettsia spp., 12% for Ehrlichia/Anaplasma spp. and 10% for Babesia spp.. At least six months after the tick bite, study participants were interviewed on symptoms by means of a standard questionnaire. 14 out of 193 participants (8.3%) reported reddening at the bite site and 6 participants (4.1%) reported systemic symptoms. No association between symptoms and tick-borne microorganisms was found. Attachment duration ≥24 h was positively associated with reddening at the bite site and systemic symptoms. Using logistic regression techniques, reddening was positively correlated with presence of Borrelia afzelii, and having 'any symptoms' was positively associated with attachment duration.

Conclusion

The risk of contracting acute Lyme borreliosis, rickettsiosis, babesiosis or ehrlichiosis from a single tick bite was <1% in this study population.

Ehrlichia species, probable emerging human pathogens in sub-Saharan Africa: environmental exacerbation

Ehrlichiae are obligate intracellular Gram-negative tick-borne bacteria that are responsible for life-threatening emerging human zoonoses and diseases of veterinary importance worldwide, collectively called ehrlichioses. The genus Ehrlichia consists of five recognized species, including E. canis, E. chaffeensis, E. ewingii, E. muris, and E. ruminantium. The recent discoveries of Ehrlichia species in new areas and of tick species that were previously thought to be uninfected by these agents have suggested that these agents may have wider distribution than originally thought. Environmental factors like temperature, migration, control failure, and host population have been known to exacerbate the spread of Ehrlichia species. Human cases of moderate to severe disease caused by E. chaffeensis have been reported mainly in North America. In this article, we present an overview of ehrlichiae as emerging pathogens in sub-Saharan Africa, where E. ruminantium, the causative agent of heartwater, a disease of domestic and wild ruminants, is most established. Molecular evidence indicates that E. ruminantium may be an emerging pathogen of a life-threatening human disease. Ehrlichia ruminantium is considered an agricultural biothreat, with several strains reported throughout sub-Saharan Africa, where the infection is considered endemic. Understanding the diversity of E. ruminantium and other Ehrlichia species from all geographically distinct areas of sub-Saharan Africa may enhance our knowledge of the pathogenesis and epidemiology of these pathogens.

Co-circulation of emerging tick-borne pathogens in Middle Germany

From May until October 2007, a total of 658 Ixodes ricinus ticks were collected off birds (189), rodents (273), and vegetation (196) in a certain area of Middle Germany and investigated for infection with Babesia spp., Anaplasma phagocytophilum, and Rickettsia spp. Overall, 13.1% (86/658) of the ticks were infected with at least one pathogen; co-infections occurred in 0.6% (4/658). Babesia spp. specific DNA was detected in 9.7% (64/658) of the ticks, 1.4% (9/658) were infected with A. phagocytophilum, and 2.6% (17/658) harbored rickettsiae. At least two different Rickettsia species were identified: Rickettsia monacensis and Rickettsia helvetica. Our study provides first interesting insights into the circulation and co-circulation of several emerging pathogens not only in ticks parasitizing birds and small mammals as potential reservoirs but also in questing ticks in a single natural habitat.

A novel Ehrlichia genotype detected in naturally infected cattle in North America

During a research investigation to determine if cattle from British Columbia (BC), Canada were infected with Anaplasma marginale or other related rickettsial blood parasites, a novel Ehrlichia genotype was revealed. Blood from seven BC source cattle was bioassayed by intravenous inoculation into naïve splenectomised calves. Additional splenectomised calves were used as uninoculated negative control or A. marginale-inoculated positive control. Newly designed sets of primers specific for the msp5 gene of A. marginale or for the 16S rRNA gene were used to test blood samples collected from all source cattle and from all recipient calves prior to inoculation and up to 72 days post-inoculation. Results of the PCR assays as well as microscopic examination of stained blood smears failed to demonstrate A. marginale in any of the animals except for the positive control. The 16S rRNA PCR primers amplified DNA from samples from all BC source cattle, five of six of the corresponding recipient calves, and the A. marginale infected control animal. DNA sequence data indicated the presence of A. marginale only in the positive control calf. Blast analysis in GenBank showed that sequences of all other 16S rRNA PCR products clearly fit within the Ehrlichia genus in the Anaplasmataceae family which also includes members of the genus Anaplasma. Phylogenetic analyses using the 16S rRNA gene sequences strongly support the putative Ehrlichia organism as a distinct genotype with sequences of various strains of Ehrlichia canis as the closest clade. Ehrlichia ruminantium is the only other species of the genus known to naturally infect cattle, apart from the present Ehrlichia isolate. However, within the genus, E. ruminantium is phylogenetically the furthest removed species from the novel genotype. The finding of this novel Ehrlichia represents the first known natural ehrlichial infection in cattle in North America. Nevertheless, it is unclear whether cattle are an incidental or primary host, particularly since deer are recognized as reservoir hosts for other species of Ehrlichia. Although other Ehrlichia spp. are known to be pathogenic for animals and zoonotic, these features are presently unknown for this novel genotype.