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Concept: Ehrlichiosis


BACKGROUND: Although tick-borne diseases are important causes of morbidity and mortality in dogs in tropical areas, there is little information on the agents causing these infections in the Caribbean. METHODOLOGY: We used PCRs to test blood from a cross-section of dogs on St Kitts for Ehrlichia (E.) canis, Babesia (B.) spp., Anaplasma (A.) spp. and Hepatozoon (H.) spp. Antibodies against E. canis and A. phagocytophilum/platys were detected using commercial immunochromatography tests. Records of the dogs were examined retrospectively to obtain clinical and laboratory data. PRINCIPAL FINDINGS: There was serological and/or PCR evidence of infections of dogs with E. canis (27%; 46/170), Babesia spp. (24%; 90/372) including B. canis vogeli (12%; 43/372) and B. gibsoni (10%; 36/372), A. platys (11%; 17/157) and H. canis (6%; 15/266). We could not identify the Babesia sp. detected in nine dogs. There was evidence of multiple infections with dual infections with E. canis and B. canis vogeli (8%; 14/179) or B. gibsoni (7%; 11/170) being the most common. There was agreement between immunochromatography and PCR test results for E. canis for 87% of dogs. Only 13% of exposed dogs had signs of a tick-borne disease and 38% had laboratory abnormalities. All 10 dogs presenting for a recheck after treatment of E. canis with doxycycline were apparently healthy although all remained seropositive and six still had laboratory abnormalities despite an average of two treatments with the most recent being around 12 months previously. Infections with Babesia spp. were also mainly subclinical with only 6% (4/67) showing clinical signs and 13% (9/67) having laboratory abnormalities. Similarly, animals with evidence of infections with A. platys and H. canis were largely apparently healthy with only occasional laboratory abnormalities. CONCLUSIONS: Dogs are commonly infected with tick-borne pathogens in the Caribbean with most having no clinical signs or laboratory abnormalities.

Concepts: Apicomplexa, Lyme disease, Tick, Caribbean, Ehrlichiosis, Saint Kitts and Nevis, Saint Kitts, Anguilla


Ehrlichiosis is a bacterial zoonosis, spread through the bites of infected ticks, that is most commonly caused in the United States by infection with the bacterium Ehrlichia chaffeensis. We retrospectively reviewed samples from an 18-month study of ehrlichiosis in the United States and found that E. ewingii was present in 10 (9.2%) of 109 case-patients with ehrlichiosis, a higher rate of infection with this species than had previously been reported. Two patients resided in New Jersey and Indiana, where cases have not been reported. All patients with available case histories recovered. Our study suggests a higher prevalence and wider geographic distribution of E. ewingii in the United States than previous reports have indicated.

Concepts: Immune system, Bacteria, Infection, United States, New Jersey, Ehrlichiosis, Ehrlichia, Ehrlichia ewingii


Hyalomma scupense (syn. Hyalomma detritum) is a two-host domestic endophilic tick of cattle and secondarily other ungulates in the Maghreb region (Africa). This species transmits several pathogens, among which two are major livestock diseases: Theileria annulata and Theileria equi. Various other pathogens are also transmitted by this tick species, such as Anaplasma phagocytophilum and Ehrlichia bovis. Hyalomma scupense is common in sub-humid and semi-arid areas of several regions in the world, mainly in the Maghreb region. In this region, adults attach to animals during the summer season; larvae and nymphs attach to their hosts during autumn, but there is a regional difference in H. scupense phenology. There is an overlap between immature and adult ticks, leading in some contexts to a dramatic modification of the epidemiology of tick-borne diseases. This tick species attaches preferentially to the posterior udder quarters and thighs. Tick burdens can reach 130 ticks per animal, with a mean of 60 ticks. Calves are 70 times less infested than adult cattle. The control can be implemented through six options: (i) rehabilitation of the farm buildings by roughcasting and smoothing the outer and inner surfaces of the enclosures and walls. This control option should be recommended to be combined with a thorough cleaning of the farm and its surrounding area. With regard to Theileria annulata infection, this control option is the most beneficial. (ii) Acaricide application to animals during the summer season, targeting adults. (iii) Acaricide application during the autumn period for the control of the immature stages. (iv) Acaricide application to the walls: many field veterinarians have suggested this option but it is only partially efficient since nymphs enter deep into the cracks and crevices. It should be used if there is a very high tick burden or if there is a high risk of tick-borne diseases. (v) Manual tick removal: this method is not efficient since the ticks can feed on several other animal species in the farm. This control option can lead to a reduction of the tick population, but not a decrease in tick-borne disease incidence. (vi) Vaccination: this control option consists of injecting the protein Hd86; trials have shown a partial effect on nymphs, with no effect on adult ticks. Combination of two of these control options is recommended in regions where there are high burdens of important tick vectors. Further studies are needed to improve our knowledge on this tick species in the Maghreb region, since the number of published studies on Hyalomma scupense in this region is very limited.

Concepts: Biology, Lyme disease, Tick, Ixodidae, Parasitiformes, Ehrlichiosis, Tick-borne disease, Maghreb


BACKGROUND: Controlling canine vector-borne diseases (CVBD) is a major concern, since some of these diseases are serious zoonoses. This study was designed to determine seropositivity rates in Spain for agents causing the following five CVBD: leishmaniosis (Leishmania infantum: Li), heartworm (Dirofilaria immitis: Di), ehrlichiosis (Ehrlichia canis: Ec), anaplasmosis (Anaplasma phagocytophilum/Anaplasma platys: An) and Lyme disease (Borrelia burgdorferi: Bb). METHODS: Anti-An, -Bb, and -Ec antibodies and the Di antigen were determined using the 4DX SNAP® Test (IDEXX Laboratories) and anti-L. infantum (Li) antibodies using the Leishmania SNAP® Test (IDEXX Laboratories) in blood and/or serum samples. RESULTS: Among 1100 dogs examined, overall seropositivity rates were: Li (15.7%), Ec (5%), An (3.1%), Di (1.25%) and Bb (0.4%). While seropositivity towards Bb and Di was similar in all geographic regions, rates were significantly higher in the east of Spain (8.3%) for An, significantly higher in the north (20%) for Ec, and significantly higher in the south (46.6%) and southeast (27.4%), and significantly lower in the north (0%) for Li. No statistical associations were observed between sex and the CVBD analyzed (p >= 0.05) while the following associations with other variables were detected: a higher seropositivity to Ec (40%) and Bb (6.7%) in dogs under one year of age compared with adults (p < 0.05); and a higher seropositivity to An and Li in dogs that lived outdoors versus indoors (p = 0.01; p < 0.001, respectively). Seropositivity rates of 2.1%, 0%, 1.7%, 0.5% and 4.2% were recorded respectively for An, Bb, Ec, Di and Li in dogs with no clinical signs (n = 556) versus 3.8%, 0.6%, 7.5%, 1.8% and 25.9% for those with signs (n = 507) suggestive of a CVBD. CONCLUSION: The data obtained indicate a risk for dogs in Spain of acquiring any of the five CVBD examined. Veterinarians in the different regions should include these diseases in their differential diagnoses and recommend the use of repellents and other prophylactic measures to prevent disease transmission by arthropod vectors. Public health authorities also need to become more involved in the problem, since some of the CVBD examined here also affect humans.

Concepts: Lyme disease, Borrelia burgdorferi, Borrelia, Dog, Ehrlichiosis, Dirofilaria immitis, Dirofilaria, Zoonoses


We report the complete genome sequence ofEhrlichia canisstrain YZ-1, which was isolated from a beagle with fever, anorexia, depression, lethargy, weight loss, and thrombocytopenia.E. canisis the tick-borne agent of canine and human monocytic ehrlichiosis.

Concepts: HIV, Cancer, Human genome, Virus, Genome, Genomics, Symptoms, Ehrlichiosis


The present study was planned to investigate the molecular prevalence of canine monocytic ehrlichiosis (CME) in dogs in and around Hisar and to evaluate the haemato-biochemical profile for its better management. A total of 60 dogs presented to Medicine Section, TVCC, LUVAS, Hisar with the history of naturally acquired tick infestation and clinical signs consistent with CME were screened on the basis of blood smear examination, followed by molecular detection by nested PCR assay targeting a portion of 16S rRNA gene of Ehrlichia canis. Nested PCR detected 18 cases positive for E. canis with estimated 30% percent positivity as compared to 8.33% (5 out of 60) by blood smear examination. These 18 dogs confirmed for CME by nested PCR were assessed for clinical and haemato-biochemical profile. Breed-wise prevalence indicated maximum number of cases in Labrador retriever, followed by Pug, Rottweiler and German shepherd dog with more number of cases in male dogs. Age-wise prevalence revealed highest number of cases in more than 1 year age group, followed by 6 months to 1 year age group and least in less than 6 months aged dogs. Pyrexia, anorexia and pale to congested mucous membranes were the main clinical signs observed, followed by lethargy, vomiting. Less common clinical signs were epistaxis, lymphadenomegaly, hind limb weakness, malena, ocular discharge, followed by haematuria, corneal opacity, nasal discharge and coughing, icterus, dermal petechiae and ecchymoses. The haematological profile revealed macrocytic hypochromic anaemia, thrombocytopenia, normal leucocyte count with relative lymphocytosis, monocytosis and neutropenia. Serum biochemistry revealed significant rise in values of ALT, AST, GGT, bilirubin total, bilirubin indirect, alkaline phosphatase and A/G ratio in affected dogs as compared to healthy control, suggesting the hepatic dysfunction. The lipid metabolites and kidney function parameters were non-significantly altered from those of healthy control. A high positivity for E. canis detected by nested PCR in dogs in and around Hisar suggests the endemicity of the disease in dogs' population in this region and warrants the screening for the disease in suspected dogs by this technique as compared to routine blood smear examination. The presented haemato-biochemical profile may be useful in presumptive diagnosis of the disease in dogs and their better clinical management.

Concepts: Epidemiology, Polymerase chain reaction, Ribosomal RNA, 16S ribosomal RNA, Hematology, Labrador Retriever, Dog, Ehrlichiosis


A 16-year-old young man presented to the emergency room with new-onset generalised tonic-clonic seizures. Examination showed a Glasgow score of 13 and predominantly crural left hemiparesis. Imaging demonstrated a right frontoparietal haemorrhage of non-vascular origin with perilesional oedema. Surgical drainage was carried out, but rebleeding occurred within 24 hours following surgery, and again 1 week after discharge. On reinterrogation and examination, Ehrlichia canis infection was suspected and empirical management with doxycycline was begun. Improvement was evident 72 hours after antibiotic initiation, and PCR confirmed the diagnosis; thus, doxycycline was continued for 6 months. After 2 years, seizures recurred and treatment was reinstated with good clinical response. However, seizures reappeared whenever treatment discontinuation was attempted. Lacking alternatives, doxycycline was maintained up to the third year following the initial episode. Subsequently, the patient showed complete resolution without neurological sequelae up to his last follow-up visit, 12 months following treatment cessation.

Concepts: Medicine, Hospital, Traumatic brain injury, Surgery, Neurology, Seizure, Ehrlichiosis


Ehrlichiosis is an emerging infectious disease of domestic animals which is transmitted by ticks. This disease has been reported earlier in most parts of China in dogs, cattle and humans, but there is no published data regarding this disease in goats. The present study provided the evidence of Ehrlichia infection in goats in Wuhan, China on the basis of clinical signs, gross lesions, serum-biochemical, histopathological and PCR. Twenty four goats were presented to the veterinary hospital of Huazhong Agricultural University during July, 2016. The goats were diagnosed for Ehrlichia in monocytic and granulocytic forms by blood smear examination. Further confirmation was done by PCR examination, while histopathological examination revealed degeneration and inflammation in different tissues. The biochemical criterion and blood samples analysis showed significant (P < 0.05) changes. The present study reported that goats are naturally exposed to Ehrlichia infection. To the best of our knowledge, this is the first clinical report of Ehrlichia infection in goats infested with infected ticks.

Concepts: Immune system, Medicine, Infectious disease, Pathology, Infection, Fever, Ehrlichiosis, Wuhan


This experiment was carried out to attain prevalence and molecular characterization of pathogens causing canine vector-borne diseases (CVBDs) including babesiosis, hepatozoonosis, leishmaniasis, filariosis (Dirofilaria immitis, Dirofilaria repens, and Acanthocheilonema reconditum), ehrlichiosis (Ehrlichia canis), and anaplasmosis (Anaplasma platys) in stray dogs. The study material consisted of 133 asymptomatic female (n = 96) and male (n = 37) stray dogs (≤1 year old, n = 16 and 1-6 years old, n = 117) housed in the Animal Care and Rehabilitation Center, Erzurum, Northeastern Turkey. Conventional and nested PCR were performed on blood samples to detect Babesia spp., Leishmania spp., Hepatozoon spp., D. immitis, D. repens, A. reconditum, E. canis, and A. platys. Sex and age association with the pathogen prevalence was determined using X(2) statistics. The positivity rate for at least one CVBD pathogen was 48.9% (65/133). DNA of B. canis, Hepatozoon spp., H. canis, D. immitis, and E. canis were detected in 5.3% (7/133), 27.1% (36/133), 5.3% (7/133), 1.5% (2/133), and 9.8% (13/133) of the dogs, respectively. Leishmania spp., D. repens, A. reconditum, and A. platys DNA were not detected. Mixed pathogens were determined in seven (10.8%) of the infected dogs, with predominant involvement of Hepatozoon spp. or H. canis. The pathogen prevalence did not vary by sex or age. Nucleotide blast analysis of Erzurum isolates showed 99.8-100% identities with the corresponding reference isolates. This study indicates presence of five CVB pathogens, including the first report of E. canis, in stray dogs in Erzurum, Turkey.

Concepts: Immune system, Polymerase chain reaction, Apicomplexa, Leishmaniasis, Dog, Ehrlichiosis, Dirofilaria immitis, Dirofilaria


Human ehrlichiosis and anaplasmosis are acute febrile tick-borne infectious diseases caused by various members from the genera Ehrlichia and Anaplasma. Ehrlichia chaffeensis is the major etiologic agent of human monocytotropic ehrlichiosis (HME), while Anaplasma phagocytophilum is the major cause of human granulocytic anaplasmosis (HGA). The clinical manifestations of HME and HGA ranges from subclinical to potentially life-threatening diseases associated with multi-organ failure. Macrophages and neutrophils are the major target cells for Ehrlichia and Anaplasma, respectively. The threat to public health is increasing with newly emerging ehrlichial and anaplasma agents, yet vaccines for human ehrlichioses and anaplasmosis are not available, and therapeutic options are limited. This article reviews recent advances in the understanding of HME and HGA.

Concepts: Immune system, Medicine, Epidemiology, Disease, Infectious disease, Infection, Rickettsiales, Ehrlichiosis