Seroprevalence and associated risk factors for vector-borne pathogens in dogs from Egypt

Epidemiology of Anaplasma species amongst cattle in Africa from 1970 to 2022: A systematic review and meta-analysis

Tick-borne pathogens of the genus Anaplasma cause anaplasmosis in livestock and humans, impacting health and livelihoods, particularly in Africa. A comprehensive review on the epidemiology of Anaplasma species is important to guide further research and for implementation of control approaches. We reviewed observational studies concerning Anaplasma species amongst cattle in Africa. Peer-reviewed studies published in PubMed, Google Scholar, and Web of Science - from database inception to 2022 - were searched. The quality of individual studies was assessed using the Joanna Briggs Institute Critical Appraisal Tool and the pooled prevalences by diagnostic method were estimated using random-effects models. Heterogeneity across the studies was tested and quantified using the Cochran's Q statistic and the I2 statistic. Potential sources of heterogeneity were investigated by subgroup analysis. A total of 1117 records were retrieved and at the end of the screening, 149 records (155 studies) were eligible for this meta-analysis. The occurrence of Anaplasma species was reported in 31/54 countries in all regions. Seven recognised species (A. marginale, A. centrale, A. phagocytophilum, A. platys, A. capra, A. bovis, A. ovis) and nine uncharacterised genotypes (Anaplasma sp. Hadesa; Anaplasma sp. Saso; Anaplasma sp. Dedessa; Anaplasma sp. Mymensingh; Anaplasma sp. Lambwe-1; Candidatus Anaplasma africae; Anaplasma sp.; Candidatus Anaplasma boleense) were reported in African cattle. Anaplasma marginale was the most frequently reported (n=144/155 studies) and the most prevalent species (serology methods 56.1%, 45.9-66.1; direct detection methods 19.9%, 15.4-24.7), followed by A. centrale (n=26 studies) with a prevalence of 8.0% (95% CI: 4.8-11.9) and A. platys (n=19 studies) with prevalence of 9.7% (95% CI: 5.4-15.2). Anaplasma marginale, A. centrale and A. platys were reported in all Africa's regions, while A. ovis and A. capra were reported only in the northern and central regions. The uncharacterised Anaplasma taxa were mostly detected in the eastern and southern regions. Subgroup analysis showed that significant determinants for A. marginale exposure (serology) were geographical region (p=0.0219), and longitude (p=0.0336), while the technique employed influenced (p<0.0001) prevalence in direct detection approaches. Temperature was the only significant variable (p=0.0269) for A. centrale. These findings show that various Anaplasma species, including those that are zoonotic, circulate in African cattle. There is need for more genetic and genome data, especially for unrecognised species, to facilitate effective identification, improve livestock and minimise the health risk in human populations. Additional epidemiological data including pathogen occurrence, tick vectors and host range, as well as pathogenicity are essential.

Effect of Breed on Hematological and Biochemical Parameters of Apparently Healthy Dogs Infected with Zoonotic Pathogens Endemic to the Mediterranean Basin

Dogs are considered the main reservoir of several zoonoses endemic to the Mediterranean Basin. In this study, a prevalence of infections and coinfections of canine vector-borne diseases was analyzed in apparently healthy dogs of different canine pure breeds in Sicily (Italy), where these diseases are endemic. The seroprevalence of Leishmania infantum, Ricketsia ricketsii, Anaplasma phagocytophilum, and Erlichia canis was assessed, as single and coinfections. Biochemical and hematological parameters were evaluated, and epidemiological factors, including sex, age, and canine breed, were recovered. The most frequent infection was L. infantum (45.61%), following R. ricketsii (36.84%), both as single, double, or triple coinfections. Coinfections change the biochemical and hematological parameters of the host, and canine breeds are related to the infection frequency and the parameters observed during infections. Changes in the complete blood count (CBC) and biochemical values also differ between canine breeds, with the Cirneco dell'Etna dogs infected with L. infantum being the animals presenting the most interesting results in our study. High values of RBC, hemoglobin, hematocrit, mean corpuscular hemoglobin (MCH), the albumin/globulin (A/G) ratio, and albumin and low levels of β-2 globulin and γ-globulin were found only in this canine breed, suggesting some resistance to infection in these dogs. Future studies about the immune response of this canine breed could be interesting to determine their possible resistance to zoonotic pathogens, such as L. infantum.

Ehrlichia canis and Rickettsia conorii Infections in Shelter Dogs: Seropositivity and Implications for Public Health

A cross-sectional study was conducted to gain insight into the epidemiology of canine ehrlichiosis and rickettsiosis in northern Portugal. Specific IgG antibodies to Ehrlichia canis were analysed using a commercial enzyme-linked immunosorbent assay (ELISA), and antibodies to Rickettsia conorii were analysed using a commercial indirect immunofluorescence antibody test (IFAT). A total of 113 dogs from two different shelters were sampled, and seroprevalence values of 0.9% (95% confidence (CI): 0.2-4.8%) for E. canis and 9.7 (95% CI: 5.5-16.6%) for R. conorii were found. Multiple logistic regression investigated risk factors for seropositivity. The odds ratios (ORs) of R. conorii seropositivity were higher for female dogs (OR = 6.429; 95% CI: 1.201-34.407). Dogs seropositive for co-infection (E. canis + R. conorii) were more frequently observed among females (OR = 7.606; CI 95%: 1.478-39.132) and in Shelter 2 (OR = 18.229; 95% CI: 2.190-151.756). These findings show that shelter dogs in northern Portugal are exposed to E. canis and R. conorii, which can affect both canines and humans. It is imperative to adopt a One Health approach to educate the public about the hazards of canine zoonoses and develop legislation and procedures to control their spread and preserve public health.

Serosurvey and associated risk factors for Neospora caninum infection in Egyptian water buffaloes (Bubalus bubalis)

Neosporosis is a parasitic disease that causes reproductive disorders in animals, making it a barrier to maximum efficiency. The purpose of this study was to determine the seroprevalence of Neospora caninum (N. caninum) antibodies in water buffaloes from four governorates in northern Egypt. A commercial indirect-ELISA test was used to detect antibodies against N. caninum in the serum of 450 water buffaloes. The total seroprevalence of N. caninum in water buffaloes from Egypt was 31.3%, and the highest prevalence was observed in Gharbia governorate. The identified risk factors for N. caninum infections in water buffaloes were sex (OR = 1.96, 95%CI: 1.22-4.17), buffaloes more than 4 years of age ( OR = 5.80, 95%CI: 2.26-14.86), abortion in second trimester (OR = 16.48, 95%%CI: 2.99-34.03), history of abortion (OR = 3.45, 95%CI: 1.58-7.52) and contact with dogs (OR = 2.55, 95%CI: 1.51-4.32). Thus, more studies are needed to determine the role of buffaloes in the epidemiology of neosporosis in Egypt.

Fasciola hepatica Infection in Horses in Three Governorates in Northern Egypt: Prevalence and Risk Factors

Fasciola hepatica is a trematode parasite that affects wide range of mammalian hosts including horses. There are no epidemiological data on fasciolosis in Egyptian horses. Hence, the present study aimed to evaluate the seroprevalence of F. hepatica in horses using ELISA as well as assess the associated risk factors for fasciolosis infection. A total of 400 sera samples of horses from three Egyptian governorates were examined. The overall seroprevalence rate in horses was 13% and the disease was more prevalent in Qalubia (14.17%) and Gharbia (16.67%) which are located at Nile Delta. The likelihood of having F. hepatica seropositivity was higher in mixed-breed animals and stallions (OR = 3.97, 95%CI: 1.10-14.28 and OR = 2.07, 95%CI: 1.09-3.93, respectively), and in older horses more than 10 years (OR = 5.69, 95% CI: 1.98-16.36). Horses were more likely to be seropositive with F. hepatica when kept in outdoor housing (OR= 1.53, 95%CI: 0.78-3), during autumn (OR = 3.80, 95%CI: 1.17-12.32) and in the presence of snails (OR = 2.72, 95%CI: 1.34-5.52). Therefore, the obtained data contributes to the understanding of the epidemiology of Fasciola species, assess in establishment of management programmes to reduce disease and public health risks.

Prevalence of Cryptosporidium infection and associated risk factors in calves in Egypt

Cryptosporidium is one of the causative parasitic agents that causes gastrointestinal diseases in calves. The parasite poses a zoonotic risk to immunocompromised individuals and children. Thus, this study aimed to determine the prevalence of Cryptosporidium infection in calves in three Egyptian governorates situated in Nile Delta and assess the associated risk factors. The Cryptosporidium oocysts were detected in 81 out of 430 calves (18.84%). In addition, the univariant analysis showed that age, feeding source, hygienic status, presence of diarrhea and contact with other animals were significantly (P < 0.05) associated with Cryptosporidium prevalence in calves. Furthermore, the risk factors related with Cryptosporidium prevalence were age (OR 1.96, 95%CI 0.97-3.94), feeding on milk and pasture (OR 2.07, 95%CI 1.15-3.72), poor hygienic condition (OR 2.25, 95%CI 1.28-3.94), presence of diarrhea (OR 2.47, 95%CI 1.23-4.96) and contact with other domestic animals (OR 2.08, 95%CI 1.24-3.50). In addition, the PCR assay targeting 18srRNA showed that the most prevalent species among calves was C. parvum. Although additional researches are required to understand the most effective steps that farmers and veterinary professionals should take to decrease the occurrence of Cryptosporidium infection.

Seroprevalence of Rift Valley Fever virus in one-humped camels (Camelus dromedaries) in Egypt

Rift Valley fever (RVF) is a mosquito-borne viral disease that affects a variety of domestic animals, including cattle, sheep, goats, and camels, and has zoonotic potential. Although the rift valley fever virus (RVFV) is usually asymptomatic in camels, it can induce abortion in some pregnant animals. In the current study, a serosurvey was carried out to investigate the prevalence of RVFV antibodies and related risk factors in camels from four Egyptian governorates. A total of 400 serum samples were examined for anti-RVFV antibodies using a competitive enzyme-linked immunosorbent assay (c-ELISA). The results revealed that the overall prevalence of RVF among examined camels was 21.5% and the disease was more prevalent in Kafr ElSheikh governorate in Nile Delta of Egypt. In addition, the age group of camels with more than 5 years (OR=4.49, 95%CI: 1.39-14.49), the female sex (OR=3.38, 95%CI: 1.51-7.58), the emaciated animals (OR=1.52, 95%CI: 0.86-2.66), the summer season's infection (OR=5.98, 95%CI: 1.79-19.93), the presence of mosquitoes (OR= 2.88, 95%CI: 1.39-5.95), and the absence of mosquitoes control (OR=3.97, 95%CI: 2.09-7.57) were identified as risk factors for RVFV infection. The results of this study support knowledge on the risk factors for RVFV infection and demonstrate that camels raising in Egypt have RVFV antibodies. Quarantine measures or vaccination program should be implemented to reduce the likelihood of RVFV introduction, dissemination among susceptible animals, and ultimately transmission to humans.

Seroprevalence and associated risk factors for Toxoplasma gondii in water buffaloes (Bubalus bubalis) in Egypt

Toxoplasmosis is a parasitic disease caused by Toxoplasma gondii and affecting all warm-blooded animals. The available data about the epidemiological situation of T. gondii in water buffaloes in Egypt are scarce. Thus, a cross-sectional study was conducted to determine the seroprevalence of T. gondii in water buffaloes in three Egyptian governorates and to evaluate the associated risk factors for the infection. A total of 430 sera samples were examined using commercial Indirect ELISA Multi-species kit. The overall seroprevalence rate of T. gondii in examined water buffaloes was 7.4 %, and the highest rate (9.3 %) was found in Kafr ElSheikh governorate. Multivariate logistic regression analysis showed that adult buffalo (OR = 7.10; 95 % CI: 0.87-57.68; P = 0.067) and small herds (OR = 8.42; 95 % CI: 1.07-66.02; P = 0.043) were more likely than young buffalo and large herds to become infected with T. gondii. Moreover, the risk of buffaloes contracting T. gondii infection was higher in winter and especially among animals contacted with cats. It is necessary to identify risk factors in order to determine what mitigation, control, and prevention strategies to implement in order to reduce, control, and prevent T. gondii infection in domestic animals, which will in turn reduce human infection with the disease.

Neospora caninum infection in dairy cattle in Egypt: a serosurvey and associated risk factors

Neospora caninum (N. caninum) is one of the causative agents that causing cattle abortion, and severe economic losses. Due to the scarcity of data on N. caninum infection in Egyptian cattle, the purpose of this study was to estimate the seroprevalence and determine the risk factors for parasite infection. In four governorates in northern Egypt, 540 blood samples from cattle were taken, and tested using a commercial ELISA kit. The overall seroprevalence of N. caninum in examined cattle was 28.89%. A multivariate logistic regression model determined that age (OR = 2.63, P < 0.001), manual milking (OR = 1.39, P = 0.14), abortion history (OR = 2.78, P < 0.0001), repetition of estrus (OR = 2.31, P < 0.0001), and contact with dogs (OR = 2.57, P < 0.0001) were significant risk factors. The findings proved that N. caninum infection was one of the factors contributing to abortion and financial losses in dairy cattle in Egypt. Therefore, the application of sanitary security and control programs is very important in dairy farms.

Human-biting ticks and zoonotic tick-borne pathogens in North Africa: diversity, distribution, and trans-Mediterranean public health challenges

North Africa is home to more than 200 million people living across five developing economies (Egypt, Libya, Tunisia, Algeria, and Morocco) and two Spanish exclaves (Ceuta and Melilla), many of whom are impacted by ticks and tick-borne zoonoses. Populations in Europe are also increasingly vulnerable to North African ticks and tick-borne zoonoses due to a combination of climate change and the movement of ticks across the Mediterranean on migratory birds, human travellers, and trafficked wildlife. The human-biting ticks and tick-borne zoonoses in North Africa are reviewed along with their distribution in the region. We also assess present and future challenges associated with ticks and tick-borne zoonoses in North African and highlight opportunities for collaboration and coordination between governments in Europe and North Africa to address public health challenges posed by North African ticks and tick-borne zoonoses.

First molecular confirmation of multiple zoonotic vector-borne diseases in pet dogs and cats of Hong Kong SAR

In recent years, the incidence of vector-borne diseases (VBDs) has increased throughout the globe. In particular, tick-borne diseases (e.g., caused by Ehrlichia canis, E. ewingii, Anaplasma phagocytophilum, A. platys, Borrelia burgdorferi sensu stricto (s.s.) and Babesia gibsoni) and mosquito-borne diseases (e.g., caused by Dirofilaria immitis) diseases pose a burden on animal health. Nevertheless, there have been no studies undertaken on the occurrence of VBDs in pet dogs and cats in Hong Kong SAR. This study fills this gap, and is the first to determine the seroprevalence of major VBDs, such as those caused by D. immitis, E. canis, E. ewingii, A. phagocytophilum, A. platys and B. burgdorferi s.s, in dogs and cats through commercially available SNAP 4Dx plus testing. Infection by all these pathogens and Babesia sp. was further assessed through PCR and DNA sequencing. A total of 224 blood samples were collected from domestic dogs (n = 159) and cats (n = 65) in Hong Kong SAR during summer 2022. Hematocrit and platelet counts were determined in each blood sample and other hematological parameters were assessed using an automatic hematology analyzer and vortex the specimen for one to two minutes at or near the highest setting to minimize the clumping. All cat sera samples were negative for tested pathogens, but antibodies against some of the pathogens were detected in dog sera samples. Here, the highest figures were recorded for seroprevalence of E. canis/E. ewingii (10.7%), followed by D. immitis (5.7%), and A. phagocytophilum/A. platys (2.5%). No B. burgdorferi s.s. antibodies were detected in any of the dogs tested. Through molecular diagnostics, we detected the presence of B. gibsoni (3.7%), E. canis (3.1%), D. immitis (5.7%), and A. phagocytophilum (1.3%). Neighbor-Joining phylogenetic trees for vector-borne pathogens (i.e., genus Anaplasma sp.) showed 100% clustering to Japan, the USA and Germany, whereas genus Ehrlichia sp. showed 100% clustering to China, Turkey, Cuba, and Greece. Similarly, genus Babesia sp. clustered 100% to India, Sri Lanka and Austria, while D. immitis clustered in Iraq, South Korea, Portugal, France, the USA and Italy. This study provides the first evidence on the occurrence of tick-borne pathogens in pet dogs in Hong Kong SAR. Based on these findings, it is recommended that appropriate screening should be undertaken in domestic dogs to evaluate the prevalence of these pathogens and promote the timely control of VBDs.

Costa Rican Genotype of Ehrlichia canis: A Current Concern

Canine monocytic ehrlichiosis (CME) is endemic to Brazil, and studies have verified that dogs have been exposed to different genotypes of Ehrlichia canis. This genetic divergence can influence the clinical response of the animals. We aimed to describe clinical and hematological changes in 125 dogs that reacted to BrTRP36, USTRP36, and CRTRP36 genotypes through enzyme immunoassays and to highlight the current concern regarding infection by the Costa Rican genotype. The results showed that 52.0% reacted to the Brazilian genotype, 22.4% reacted to the Costa Rican genotype, and 16.0% reacted to the American genotype, and some co-reactions were observed. Dogs reactive to BrTRP36 were 1.24% more likely to present with medullary regeneration in cases of anemia and 3% less likely to manifest hyperproteinemia, while dogs reactive to CRTRP36 were 0.7% less likely to present with medullary regeneration. Febrile illness and neurological alterations were also statistically associated, with an 85.7% and 231.2% increased likelihood, respectively, to occur in dogs that reacted to USTRP36. The dogs with the American genotype developed clinical manifestations related to systemic inflammation, while those with the Brazilian genotype of E. canis were more dispersed in the region studied, showing greater adaptation to the hosts. We highlight the significant serocurrence of the Costa Rican genotype, which has already been described to have zoonotic potential and which showed less adaptation.

Companion Vector-Borne Pathogens and Associated Risk Factors in Apparently Healthy Pet Animals (Dogs and Cats) in Khukhot City Municipality, Pathum Thani Province, Thailand

Pet animals (dogs and cats) can be infected with several companion vector-borne pathogens (CVBPs). Morbidity and mortality have been reported in pet animals due to CVBP infections. Pet animals living in close proximity to humans are able to transmit zoonotic pathogens. This study used molecular techniques to investigate the prevalence of CVBPs in apparently healthy pet animals (dogs and cats) from Khukhot City Municipality, Pathum Thani province, Thailand. In total, 210 blood samples were randomly collected from 95 dogs and 115 cats for the detection of seven companion vector-borne pathogens (Anaplasma, Babesia, Bartonella, Ehrlichia, Hepatozoon, Mycoplasma, and Rickettsia) using polymerase chain reaction. The results showed that 10.5% (22/210) of apparently healthy pet animals were infected with at least one pathogen, comprising 6 dogs (6.3% of all dogs tested) and 16 cats (13.9% of all cats tested). Ehrlichia (6.3%) was present only in dogs; furthermore, 1.1% of the dogs were positive for Anaplasma. There was one dog case co-infected with two pathogens (1.1%). In cats, Mycoplasma (9.6%) was the predominant CVBP, followed by Rickettsia (4.4%). The DNA sequences of all positive animals were 97–99% homologous to those found in the GenBank™ database for all CVBPs identified, namely Ehrlichia canis, Anaplasma platys, Rickettsia felis, Mycoplasma haemofelis, and Candidatus Mycoplasma haemominutum. Additionally, the risk of infection with CVBPs in pets was significantly associated with age, with young dogs more likely to be infected with CVBPs than adult dogs (OR 8.5, 95% CI 1.4–50.1, p = 0.006), while adult cats were more likely to be infected with CVBPs than young cats (OR 3.8, 95% CI 1.0–14.0, p = 0.038). The detection of CVBPs demonstrated the potential risk of infection that may occur in apparently healthy pet animals in Pathum Thani province. These results confirmed that apparently healthy pet animals may still be at risk of vector-borne infections and could maintain the infection cycle in pet populations. Furthermore, sampling a greater number of apparently healthy pet animals may disclose predictors of CVBP positivity in domesticated animals in this area.

Epidemiological Survey on Tick-Borne Pathogens with Zoonotic Potential in Dog Populations of Southern Ethiopia

Dogs are known to host several tick-borne pathogens with zoonotic potential; however, scant information is available on the epidemiology of these pathogens in low-income tropical countries and in particular in sub-Saharan Africa. With the aim of investigating a wide range of tick-borne pathogens (i.e., Rickettsia spp., Anaplasma spp., Erhlichia spp., Borrelia spp., Hepatozoon spp. and Babesia spp.), 273 blood samples were collected from dogs in selected districts of Ethiopia and analyzed by real-time and/or end-point PCR. The results of the study showed that Hepatozoon canis was the most prevalent pathogen (53.8%), followed by Anaplasma phagocythophilum (7.0%), Babesia canis rossi (3.3%), Ehrlichia canis (2.6%) and Anaplasma platys (2.2%). Furthermore, five samples tested positive for Borrelia spp., identified as Borrelia afzelii (n = 3) and Borrelia burgdorferi (n = 2), and two samples for Rickettsia spp., identified as Rickettsia conorii (n = 1) and Rickettsia monacensis (n = 1). The finding of Anaplasma phagocythophilum and different species of the genera Borrelia and Rickettsia with zoonotic potential was unexpected and alarming, and calls for further investigation on the roles of dogs and on the tick, species acting as vector in this specific context. Other pathogens (Hepatozoon canis, Babaesia canis rossi, Anaplasma platys, Ehrlichia canis) are already known to have an important impact on the dogs' health but have minor zoonotic potential as they were rarely or never reported in humans. Dogs from rural areas were found to be at higher risk for different pathogens, probably due to the presence of other wild canids in the same environment. The findings of the present study contribute to a better knowledge of the epidemiology of tick-borne pathogens, which is relevant to human and animal health.

Ehrlichiosis in Dogs: A Comprehensive Review about the Pathogen and Its Vectors with Emphasis on South and East Asian Countries

Ehrlichiosis in dogs is an emerging vector borne rickettsial zoonotic disease of worldwide distribution. In general, three Ehrlichial species (Ehrlichia canis, E. ewingii, and E. chaffeensis) are involved in infecting dogs. Among them, E. canis is the well-known etiological pathogen affecting platelets, monocytes, and granulocytes. Dogs act as a reservoir, while the main vector responsible for disease transmission is Rhipicephalus sanguineus. However, in east Asian countries, Haemaphysalis longicornis is considered the principal vector for disease transmission. This disease affects multiple organs and systems and has three clinical manifestations, including acute, subclinical, and chronic. Definitive diagnosis involves visualization of morulae on cytology, detection of antibodies through an indirect immunofluorescence test (IFAT), and DNA amplification by polymerase chain reaction (PCR). In canine ehrlichiosis, no predilection of age or sex is observed; however, Siberian Huskies and German Shepherds are more likely to develop severe clinical manifestations. Doxycycline, rifampicin, and minocycline are proven to be effective drugs against canine ehrlichiosis. This review is intended to describe a brief overview of Ehrlichia infection in dogs, its reported prevalence in east and south Asian countries, and the latest knowledge regarding chemotherapy and associated vectors responsible for the disease transmission. This manuscript also identifies the prevailing knowledge gaps which merit further attention by the scientific community.

Nanopore Sequencing Using the Full-Length 16S rRNA Gene for Detection of Blood-Borne Bacteria in Dogs Reveals a Novel Species of Hemotropic Mycoplasma

Dogs across the globe are afflicted by diverse blood- and vector-borne bacteria (VBB), many of which cause severe disease and can be fatal. Diagnosis of VBB infections can be challenging due to the low concentration of bacteria in the blood, the frequent occurrence of coinfections, and the wide range of known, emerging, and potentially novel VBB species encounterable. Therefore, there is a need for diagnostics that address these challenges by being both sensitive and capable of detecting all VBB simultaneously. We detail the first employment of a nanopore-based sequencing methodology conducted on the Oxford Nanopore Technologies (ONT) MinION device to accurately elucidate the "hemobacteriome" from canine blood through sequencing of the full-length 16S rRNA gene. We detected a diverse range of important canine VBB, including Ehrlichia canis, Anaplasma platys, Mycoplasma haemocanis, Bartonella clarridgeiae, "Candidatus Mycoplasma haematoparvum", a novel species of hemotropic mycoplasma, and Wolbachia endosymbionts of filarial worms, indicative of filariasis. Our nanopore-based protocol was equivalent in sensitivity to both quantitative PCR (qPCR) and Illumina sequencing when benchmarked against these methods, achieving high agreement as defined by the kappa statistics (k > 0.81) for three key VBB. Utilizing the ability of the ONT' MinION device to sequence long read lengths provides an excellent alternative diagnostic method by which the hemobacteriome can be accurately characterized to the species level in a way previously unachievable using short reads. We envision our method to be translatable to multiple contexts, such as the detection of VBB in other vertebrate hosts, including humans, while the small size of the MinION device is highly amenable to field use. IMPORTANCE Blood- and vector-borne bacteria (VBB) can cause severe pathology and even be lethal for dogs in many regions across the globe. Accurate characterization of all the bacterial pathogens infecting a canine host is critical, as coinfections are common and emerging and novel pathogens that may go undetected by traditional diagnostics frequently arise. Deep sequencing using devices from Oxford Nanopore Technologies (ONT) provides a solution, as the long read lengths achievable provide species-level taxonomic identification of pathogens that previous short-read technologies could not accomplish. We developed a protocol using ONT' MinION sequencer to accurately detect and classify a wide spectrum of VBB from canine blood at a sensitivity comparable to that of regularly used diagnostics, such as qPCR. This protocol demonstrates great potential for use in biosurveillance and biosecurity operations for the detection of VBB in a range of vertebrate hosts, while the MinION sequencer's portability allows this method to be used easily in the field.

Detection of zoonotic vector-borne pathogens in domestic dogs in Giza, Egypt

The public health implications of zoonotic vector-borne pathogens are numerous because domestic animals, such as dogs, live in close proximity to humans. Blood was collected from 116 domestic dogs in Cairo, Egypt from three different settings at the human-animal interface. The three settings the dogs came from were: privately owned animals seeking care at the Cairo University Faculty of Veterinary Medicine Clinic, non-laboratory reared research dogs maintained at the Cairo University Faculty of Veterinary Medicine, and an urban private animal rescue in Shabramont, Giza, Egypt. Enrolled animals were visually inspected for presence of flea or tick ectoparasites, Rhipicephalus sanguineus sensu lato ticks were recovered from 56 enrolled animals and a flea identified as Ctenocephalides felis was recovered from one animal. To test for past and/or current infection with vector-borne pathogens, conventional PCR and IDEXX SNAP® 4Dx® Plus were performed on whole blood. Pathogen targets included: Anaplasma spp., Ehrlichia spp., Babesia spp., Borrelia spp., Bartonella spp., Dirofilaria spp., and Rickettsia spp. Among dogs sampled across all locations, one dog was positive for Babesia sp. infection and one dog was positive for Anaplasma sp. infection as detected by PCR and confirmed by Sanger sequencing. Three additional dogs were positive for infection but had incomplete sequences obtained: two for Ehrlichia sp. and one for Borrelia sp. The SNAP® test results for all sampled dogs included: eight dogs positive for Anaplasma spp., 14 dogs positive for Ehrlichia spp., and five additional dogs positive for both Anaplasma spp. and Ehrlichia spp. SNAP® test results by sampling location showed that 66% of the dogs at the animal rescue were positive for Anaplasma spp. and/or Ehrlichia spp., 17% of the privately owned dogs at the Faculty of Veterinary medicine were positive for Anaplasma spp. and/or Ehrlichia spp., and none of the research dogs were positive for any of the targets on the SNAP® test. This high proportion of seropositivity in the animals sampled indicates a vector population which is not well controlled and a need for continued owner education and promotion of consistent use of preventive medications and the risk for zoonotic transmission.

Screening and phylogenetic characterization of tick-borne pathogens in a population of dogs and associated ticks in Egypt

Background

The incidence or recurrence of tick-borne diseases (TBDs) in animals and humans is increasing rapidly worldwide, but there is insufficient information about TBDs infecting dogs in Egypt. Thus, the present study was conducted to screen and genetically identify tick-borne pathogens (TBPs) in dogs and associated ticks by microscopic examination and polymerase chain reaction (PCR).

Methods

In Cairo and Giza governorates, 208 blood samples were collected from dogs of different breeds, ages, and sex. In addition, 1266 dog-associated ticks were collected (546 ticks were used to prepare hemolymph smears, and 720 ticks were kept in 70% ethanol until PCR analysis). PCR was applied to 124 dog blood samples and 144 tick pools prepared from 720 ticks.

Results

All ticks collected from dogs were Rhipicephalus sanguineus (s.l.). Microscopic examination revealed that TBP prevalence among dogs was 23.56% (49/208), including Anaplasma and Ehrlichia with 11.1% (23/208) and Babesia canis with 8.2% (17/208). Hepatozoon canis was not detected in blood smears. Co-infections with two pathogens were visible in 4.33% (9/208) of examined dogs. The prevalence of TBPs in hemolymph smears was 45.97% (251/546) including 35.89% (196/546) for H. canis, 8.1% (44/546) for B. canis, and 2.01% (11/546) for Anaplasmataceae (A. phagocytophilum, A. marginale, A. platys, and E. canis). The overall molecular prevalence rate of TBPs was 25.81% and 29.17% in the blood of examined dogs and in ticks, respectively. The molecular prevalence of Anaplasmataceae family, Babesia canis, and H. canis in dog blood samples was 19.35%, 6.45%, and 0.0%, respectively, while in ticks, it was 20.83%, 5.55%, and 2.8%, respectively. A sequential analysis identified six different species of TBPs, namely B. canis vogeli, Hepatozoon canis, A. phagocytophilum, A. marginale, A. platys, and E. canis. The obtained sequences were submitted to GenBank and assigned accession numbers.

Conclusions

The present study detected a wide range of TBPs (B. canis, H. canis, A. platys, A. phagocytophilum, A. marginale, and E. canis) that are considered a threat to domestic animals and humans in Egypt. Hepatozoon canis and A. marginale were reported in dogs and associated ticks for the first time in Egypt.

Graphical Abstract

Traditional and molecular techniques were used to screen domestic dogs and attached ticks for TBPs.

A wide range of TBPs in dogs and attached ticks was detected in Egypt.

Some accidental pathogens, such as A. marginale from other hosts, were identified in dogs.

Some canine isolates from Anaplasmataceae family have high homology to those isolated from humans.

The first study on the seroprevalence of Anaplasma spp. in small ruminants and assessment of associated risk factors in North Egypt

Background and Aim

Ovine anaplasmosis is a rickettsial disease caused by Anaplasma spp. These Gram-negative intracellular bacteria are mainly transmitted by ticks and infected blood cells of caprine, ovine, and wild small ruminants. At present, epidemiological data on anaplasmosis in cattle, dogs, and camels in Egypt are available, but the data about Anaplasma spp. in sheep and goat are scarce. This study aimed to determine the seroprevalence of Anaplasma spp. in small ruminants and assess the associated risk factors.

Materials and Methods

A cross-sectional study was performed to investigate the seroprevalence of Anaplasma spp. in 300 sheep and 300 goats from four governorates in North Egypt using a commercial competitive enzyme-linked immunosorbent assays kit, and the associated risk factors for the infection were evaluated.

Results

Overall, the seroprevalence of anti-Anaplasma antibodies was 18.3% and 21.3% in sheep and goats, respectively. A multivariable logistic regression model was used to determine the association between risk factors and Anaplasma spp. infection.

Conclusion

Age, animal husbandry, acaricide use, tick infestation, and contact with cattle were the primary risk factors for Anaplasma seropositivity. This study confirms the presence of antibodies against Anaplasma spp. in small ruminants from Egypt. This is the first study to assess the associated risk factors for Anaplasma infection in small ruminants from Egypt. Further studies are needed to improve the understanding of the associated disease factors, facilitating the development of new procedures for control of anaplasmosis in livestock.

Molecular epidemiological survey, genetic characterization and phylogenetic analysis of Anaplasma ovis infecting sheep in Northern Egypt

Anaplasma ovis is the most common etiologic agent of ovine anaplasmosis, mainly transmitted by ticks. The present study aimed to determine the molecular prevalence of A. ovis in sheep from Egypt and assessed the associated risk factors. The study was conducted, between January and December 2020, in four governorates situated in Northern Egypt. Blood samples from 355 asymptomatic sheep were collected and examined by the use of PCR specific to A. ovis. Diversity analysis and phylogenetic study based on partial msp4 gene sequence were performed on revealed A. ovis DNA. Overall, the molecular prevalence rate of A. ovis was 15.5% and the highest rate was observed in Kafr ElSheikh governorate (16.8%). Statistical analysis revealed that A. ovis infection was significantly related to sheep gender and to tick infestation. The risk factors that were found to be associated with A. ovis infection in exposed sheep were: female sex (OR=2.6, 95%CI: 1.13-6.12), and infestation with ticks (OR=2.1, 95%CI: 1.11-3.79). The analysis of A. ovis msp4 sequences revealed two different genotypes classified in the Old World sub-cluster with other Egyptian isolates. Investigation on prevalence, risk factors and genetic variability of A. ovis in sheep reported in this study is important for the implementation of control programs. Further studies are needed to determine the vectors and reservoirs of A. ovis in Egyptian small ruminants and to identify the real economic impact of A. ovis infection on the country.

Prevalence and risk factors associated with tropical theileriosis in Egyptian dairy cattle

Background and Aim:

Theileria annulata is the most prevalent piroplasm infecting cattle across Egypt. Theileriosis is transmitted by ixodid ticks of the genus Hyalomma. This study aimed to estimate the prevalence of theileriosis in cattle and their associated risk factors for infection.

Materials and Methods:

A total of 570 blood samples were collected from cattle from five governorates (administrative districts) in Egypt and examined using a polymerase chain reaction assay to estimate the prevalence of tropical theileriosis and assess the associated risk factors

Results:

The overall prevalence rate was 16.49%, with the Alexandria district having the highest prevalence. The results revealed that the risk of theileriosis was elevated in older cattle (odds ratio [OR]=8.9, 95% confidence interval [CI]: 3.6-21.9), especially in summers (OR=3.07, 95% CI: 1.4-6.3). Cattle heavily infested with ticks were at particular risk (OR=3.05, 95% CI: 2.1-4.5), as were those to which acaricide had not been applied (OR=13.7, 95% CI: 5.6-33.6).

Conclusion:

Understanding the risk factors associated with T. annulata infection and regular infection monitoring could reduce infection rates and economic losses and is essential for the implementation of efficient control programs.

Identification and discrimination of Theileria annulata by polymerase chain reaction-restriction fragment length polymorphism

Background and Aim:

Theileria annulata infection is a tick-borne disease affecting ruminants in the tropical and subtropical regions causing severe economic losses. This study aimed to characterize circulating T. annulata isolates from four governorates (administrative districts) north and south of Egypt using polymerase chain reaction (PCR)-restriction fragment length polymorphism.

Materials and Methods:

Fifty samples were collected from the four governorates of Egypt and were examined by a PCR assay based on the heat shock protein 70 gene. The amplified product was subsequently digested using two restriction enzymes, Taq I and Alu I, to determine which pattern of T. annulata strains was involved.

Results:

The findings revealed that one distinct pattern was observed for T. annulata isolates in the northern governorates and another one in the southern governorates. The Taq I enzyme produced three fragments (100, 175, and 270 bp), and the Alu I enzyme produced four fragments (60, 90, 125, and 270 bp).

Conclusion:

This study determined the presence of two distinct circulating genotypes of T. annulata among cattle in Egypt based on PCR-RFLP using the HSP 70 gene. More studies are needed in different parts of the country to investigate the virulence and strain variance of T. annulata in cattle.

Canine microfilaraemia in some regions of Iran

Background

Dirofilaria immitis and Dirofilaria repens are vector-borne zoonotic parasites which affect mainly dogs and humans worldwide. In Iran, information about the distribution of those nematodes is scant in several regions. Therefore, we investigated the prevalence of these filarial parasites in stray dogs from five Iranian provinces where no information about these parasites is available.

Methods

Blood samples were collected from 344 stray dogs in five provinces of Iran (i.e. Mazandaran, Gilan, Esfahan, Qazvin and Loresan). The presence of microfilariae was assessed using direct smear, modified Knott’s test, molecular detection of filarial DNA (cox1 gene) and Wolbachia endosymbiont of parasitic nematodes (ftsZ gene) by conventional PCR (cPCR). All of the PCR products were sequenced and phylogenetic analysis was performed.

Results

In total, 75 dogs (21.8%) were found to be positive for D. immitis by cPCR. Infection was detected in all provinces, with the highest prevalence in Gilan province (22/28; 78.6%). Acanthocheilonema reconditum was diagnosed in five dogs (1.4%) from three provinces (i.e. Esfahan, Mazandaran, Gilan). Two dogs were infected with both parasites and three were only infected with A. reconditum. Dirofilaria repens infection was not found in the examined population. Representative sequences of the D. immitis cox1 gene from dogs from the northern provinces (Mazandaran, Gilan, Qazvin) were grouped together and distinctly separate from the ones from western and central provinces (Lorestan and Esfahan), suggesting that different nematode populations are present in the country.

Conclusion

The data reported herein fill existing gaps in knowledge about canine filarial infection in two Iranian provinces and record the highest prevalence of D. immitis ever reported in the country (i.e. 78.6%). A geographical review of the literature about Dirofilaria spp. and A. reconditum infections in dogs and humans has also been summarized, indicating that D. immitis and D. repens are distributed in 22 of 31 provinces in Iran, whereas A. reconditum is present in fewer regions. Effective control strategies are advocated for owned dogs, and a national program for the management of stray dogs is needed to minimize the risk of infection in animals and humans.

Graphical Abstract

Serological and molecular surveys of Anaplasma spp. in Egyptian cattle reveal high A. marginale infection prevalence

BACKGROUND

Bovine anaplasmosis is an infectious disease with worldwide distribution. It spreads by various routes mainly through tick bites.

AIMS

This study aimed to investigate bovine related Anaplasma spp. in cattle from three northern governorates of Egypt by serological and molecular assays, to evaluate the associated risk factors and to analyze the phylogeny of revealed A. marginale isolates.

METHODS

During 2020, a total of 650 blood samples were collected from asymptomatic cattle in the governorates of Kafr El-Sheikh (n=240), Menofia (n=230), and Al-Gharbia (n=180). Sera samples were examined using the Anaplasma antibody test kit, cELISA v2. Blood genomic DNA of seropositive cattle was then examined by PCRs specific to A. marginale, A. centrale, and A. bovis. Selected positive samples were subjected to nucleotide sequencing. Risk factors (i.e. geographical area, breed, type of production, sex, age, herd size, season, husbandry system, tick infestation, and application of acaricides) were evaluated by logistic regression approach.

RESULTS

In total, 130 cattle (20%, 95% CI: 17.1-23.3) were recorded seropositive for Anaplasma species. Major risk factors associated with seropositivity were being crossbred, dairy cattle, aged more than 5 years, summer season, herd size of below 300, pasture grazing, tick infestation, and not being subjected to regular treatment with acaricides. By using species-specific PCR, only A. marginale was detected. Nucleotide sequencing showed the occurrence of two different msp4 genotypes.

CONCLUSION

This study shows the high prevalence of A. marginale in cattle of Kafr El-Sheikh, Al-Gharbia, and Menofia. However, the connection between Anaplasma species and their tick vectors remains unknown in Egypt and merits further investigations. Since these infections primarily spread through ixodid tick bites, effective ectoparasite control strategies, regular examination of cattle and successful chemoprophylaxis are recommended.

Assessment of Seroprevalence and Associated Risk Factors for Anaplasmosis in Camelus dromedarius

(1) Background: Anaplasmosis is an infectious disease in camels caused by an obligate intracellular bacterium that is transmitted by ticks. (2) Methods: A cross-sectional study was conducted during 2020 to study the seroprevalence of Anaplasma spp. among Camelus dromedarius in three governorates in Egypt and assess the associated risk factors. Serum samples from 365 camels were examined by a competitive enzyme-linked immunosorbent assay (cELISA) test. (3) Results: Overall, the seroprevalence of anaplasmosis among camels was 18.6%. Multivariable logistic regression was performed, and it was discovered that tick infestation, application of acaricides, grooming practice and body condition were potential risk factors for Anaplasma spp. infection (odds ratio > 1) in dromedary camels. In contrast, the locality in which the camels lived and their age were not significant effects with regard to the occurrence of anaplasmosis. (4) Conclusions: The current findings suggest that improvement of protective measures to limit the effects of the identified risk factors can help to reduce the spread of anaplasmosis among camels in Egypt.

Molecular detection and risk factors for Anaplasma platys infection in dogs from Egypt

Background

Anaplasma platys is a tick-borne bacterium which infects blood platelets of dogs, causing canine cyclic thrombocytopenia. The disease is distributed worldwide, particularly in the tropics and subtropics, but information on the epidemiology of A. platys infection in dogs is fragmentary in many countries, including Egypt. In this study, we investigated the prevalence and risk factors associated with A. platys infection in dogs from Egypt.

Methods

A conventional PCR targeting a fragment of the 16S rRNA gene of A. platys was used to screen 500 dogs from five North Egyptian governorates. DNA sequencing and phylogenetic analysis were performed for one of the positive samples.

Results

The overall prevalence of A. platys in the studied dogs was 6.4%. Females of the German shepherd breed without veterinary care had higher odds for A. platys positivity. High tick infestation and lack of anti-tick treatment were also identified as risk factors for A. platys infection. Phylogenetic analysis revealed that the sequence obtained herein was closely related to sequences from Egypt, South Africa and Uruguay.

Conclusions

This is the first large-scale epidemiological study of A. platys in Egypt, where female German shepherd dogs without veterinary care, as well as dogs with high tick infestation and without anti-tick treatment are at a higher risk of infection.

Graphical abstract