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Christopher D. Paddock - One of the best experts on this subject based on the ideXlab platform.
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Distribution and Establishment of the Lone Star Tick in Connecticut and Implications for Range Expansion and Public Health
Journal of medical entomology, 2018Co-Authors: Kirby C. Stafford, Christopher D. Paddock, Goudarz Molaei, Eliza A.h. Little, Sandor E. Karpathy, Andrew M. LabonteAbstract:In the United States, the lone star tick, Amblyomma americanum (L.) (Acari: Ixodidae), is an aggressive southeastern species whose range has reportedly been steadily expanding northward. The number of A. americanum specimens submitted to the Tick Testing Laboratory (TTL) at the Connecticut Agricultural Experiment Station (CAES) increased by 58% from the period of 1996-2006 (n = 488) to 2007-2017 (n = 773), mainly from Fairfield County in the southwestern corner of the state. The greatest numbers of A. americanum submissions to the CAES-TTL were from the City of Norwalk and a few adjacent municipalities. We also report the discovery of a large infestation of adult and nymphal lone star ticks detected on a dead male white-tailed deer, Odocoileus virginianus (Zimmerman) (Artiodactyla: Cervidae), on Manresa Island, Norwalk, in June 2017, indicating a long established, undetected population along the southwestern coast. A sample of nymphal and adult host-seeking A. americanum collected July 2017 from Manresa Island were tested and a proportion were positive for Ehrlichia chaffeensis, Ehrlichia ewingii, and Anaplasma phagocytophilum. The A. americanum tick and its associated disease pathogens are expected to become an increasing public health concern in southern New England.
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Evaluation of Gulf Coast Ticks (Acari: Ixodidae) for Ehrlichia and Anaplasma Species.
Journal of medical entomology, 2017Co-Authors: Michelle E. J. Allerdice, Sandor E. Karpathy, Joy A. Hecht, Christopher D. PaddockAbstract:Amblyomma maculatum Koch (the Gulf Coast tick) is an aggressive, human-biting ixodid tick distributed throughout much of the southeastern United States and is the primary vector for Rickettsia parkeri, an emerging human pathogen. Amblyomma maculatum has diverse host preferences that include white-tailed deer, a known reservoir for Ehrlichia and Anaplasma species, including the human pathogens E. ewingii and E. chaffeensis. To examine more closely the potential role of A. maculatum in the maintenance of various pathogenic Ehrlichia and Anaplasma species, we screened DNA samples from 493 questing adult A. maculatum collected from six U.S. states using broad-range Anaplasmataceae and Ehrlichia genus-specific PCR assays. Of the samples tested, four (0.8%) were positive for DNA of Ehrlichia ewingii, one (0.2%) was positive for Anaplasma platys, and one (0.2%) was positive for a previously unreported Ehrlichia species closely related to Ehrlichia muris and an uncultivated Ehrlichia species from Haemaphysalis longicornis ticks in Japan. No ticks contained DNA of Ehrlichia chaffeensis, Ehrlichia canis, the Panola Mountain Ehrlichia, or Anaplasma phagocytophilum. This is the first identification of E. ewingii, A. platys, and the novel Ehrlichia in questing Gulf Coast ticks; nonetheless the low prevalence of these agents suggests that A. maculatum is not likely an important vector of these zoonotic pathogens.
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first reported case of Ehrlichia ewingii involving human bone marrow
Journal of Clinical Microbiology, 2014Co-Authors: Brandon M Allen, Christopher D. Paddock, Bobbi S. Pritt, Lynne M. Sloan, Chaitanya K Musham, Jeanette M Ramos, Neslihan Cetin, Eric R RosenbaumAbstract:A 65-year-old female with a history of multiple tick bites presented with fever and pancytopenia. Intracytoplasmic rickettsial morulae were detected on peripheral smear and bone marrow biopsy specimens, and PCR amplified Ehrlichia ewingii DNA from both specimens. To our knowledge, this is the first report of E. ewingii infection of human bone marrow.
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Other Causes of Tick-Borne Ehrlichioses, Including Ehrlichia ewingii
Tick-Borne Diseases of Humans, 2014Co-Authors: Christopher D. Paddock, Allison M. Liddell, Gregory A. StorchAbstract:At least three species of tick-borne bacteria in the genera Ehrlichia (Ehrlichia chaffeensis and Ehrlichia ewingii) and Anaplasma (Anaplasma phagocytophilum) cause moderately severe to life-threatening infections in humans, and they are collectively termed human ehrlichioses. In addition, Ehrlichia canis was recently isolated from a patient without clinical signs of illness; the role of this pathogen as a cause of human disease remains incompletely defined. In this chapter, an understanding of the epidemiology and ecology of E. ewingii and characterization of the disease it causes are relatively nascent. Areas for future investigation in the natural history of E. ewingii include field investigations that define roles of tick species other than A. americanum and vertebrate hosts other than dogs and deer. Understanding the frequency and mechanism of asymptomatic canine infection may provide insights to the pathogenesis of E. ewingii infections in natural and non-natural hosts. Prospective active surveillance is needed to better identify (i) the numbers of cases of disease in humans caused by E. ewingii, (ii) the geographical distribution of disease in humans, and (iii) the spectrum of clinical disease in various human cohorts. More robust laboratory techniques need to be developed, including methods to isolate E. ewingii in cell culture and serological techniques to distinguish this infection from human monocytic ehrlichiosis. It is likely that other tick-borne Ehrlichiae will be recognized eventually as additional agents of human ehrlichioses around the world. The key to identifying novel agents lies in the perspicacity of, and cooperation among, clinicians, veterinarians, epidemiologists, and laboratorians.
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TISSUE DIAGNOSIS OF Ehrlichia CHAFFEENSIS IN PATIENTS WITH FATAL EHRLICHIOSIS BY USE OF IMMUNOHISTOCHEMISTRY, IN SITU HYBRIDIZATION, AND POLYMERASE CHAIN REACTION
2013Co-Authors: Jacqueline E Dawson, Christopher D. Paddock, Ulrike G Munderloh, Cynthia K. Warner, Patricia W. Greer, S. A. Ewing, Jeanine H. Bartlett, R. Zaki, Infectious Disease Pathology ActivityAbstract:Abstract. In the United States, human ehrlichiosis is a complex of emerging tick-borne diseases caused by 3 distinct Ehrlichia species: Ehrlichia chaffeensis, Ehrlichia ewingii, and the human granulocytotropic ehrlichiosis agent. Ehrlichioses are characterized by a mild to severe illness, and � 4 % of cases are fatal. Because these obligate intracellular bacteria are difficult to resolve with routine histologic techniques, their distribution in tissues has not been well described. To facilitate the visualization and detection of Ehrlichiae, immunohistochemistry (IHC), in situ hybridization (ISH), and polymerase chain reaction (PCR) assays were developed by use of tissues from 4 fatal cases of E. chaffeensis infection. Evidence of E. chaffeensis via IHC, ISH, and PCR was documented in all 4 cases. Abundant immunostaining and in situ nucleic acid hybridization were observed in spleen and lymph node from all 4 patients. Significantly, in 2 of these patients, serologic evidence of infection was absent. Use of IHC, ISH, and PCR to visualize and detect Ehrlichia in tissues can facilitate diagnosis of Ehrlichial infections
Susan E. Little - One of the best experts on this subject based on the ideXlab platform.
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persistent Ehrlichia ewingii infection in dogs after natural tick infestation
Journal of Veterinary Internal Medicine, 2015Co-Authors: Lindsay A Starkey, Melissa J Beall, Anne W Barrett, Ramaswamy Chandrashekar, Brendon Thatcher, Phyllis Tyrrell, Susan E. LittleAbstract:Background Ehrlichia ewingii, which causes disease in dogs and people, is the most common Ehrlichia spp. infecting dogs in the United States, but little is known about how long E. ewingii infection persists in dogs. Hypothesis/Objectives To evaluate the persistence of natural infection with E. ewingii in dogs. Animals Four Class A Beagles; no previous exposure to ticks or tick-borne infectious agents. Methods Dogs were exposed to ticks by weekly walks through tick habitat in north central Oklahoma; dogs positive for infection with Ehrlichia spp. by sequence-confirmed PCR and peptide-specific serology were evaluated for 733 days (D). Whole blood was collected once weekly for PCR, and serum was collected once monthly for detection of antibodies to Ehrlichia canis (peptide p16), Ehrlichia chaffeensis (indirect fluorescence antibody [IFA] and variable-length PCR target [VLPT]), and E. ewingii (peptide p28). Results All dogs (4/4) became infected with Ehrlichia spp. as evidenced by seroconversion on IFA to E. chaffeensis (4/4); PCR detection of E. ewingii (4/4) and E. chaffeensis (2/4) DNA using both nested and real-time assays; and presence of specific antibodies to E. ewingii (4/4) and E. chaffeensis (2/4). Infection with E. chaffeensis was not detected after D55. Intermittent E. ewingii rickettsemia persisted in 3 of 4 dogs for as long as 733 days. Conclusions and Clinical Importance Our data demonstrate that dogs infected with E. ewingii from tick feeding are capable of maintaining infection with this pathogen long-term, and may serve as a reservoir host for the maintenance of E. ewingii in nature.
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prevalence of antibodies to spotted fever group rickettsia spp and Ehrlichia spp in coyotes canis latrans in oklahoma and texas usa
Journal of Wildlife Diseases, 2013Co-Authors: Lindsay A Starkey, Anne W Barrett, Jill Saucier, Mason V Reichard, Misti D West, Thomas P Oconnor, Kelsey L Paras, Michael H Reiskind, Susan E. LittleAbstract:Coyotes (Canis latrans) are commonly infested with ticks, including Amblyomma americanum, the predominant vector of Ehrlichia chaffeensis and Ehrlichia ewingii; Dermacentor variabilis, an important vector of Rickettsia rickettsii; and Amblyomma maculatum, a major vector of Rickettsia parkeri, a spotted fever group (SFG) Rickettsia. To determine the degree to which coyotes are infected with or exposed to tick-borne bacterial disease agents, serum samples collected from coyotes in Oklahoma and Texas were tested for antibodies reactive to R. rickettsii, Ehrlichia canis, E. chaffeensis, E. ewingii, Borrelia burgdorferi, and Anaplasma phagocytophilum by indirect fluorescent antibody (IFA) testing or enzyme-linked immunosorbent assay (ELISA). Of the coyotes tested, 60% (46/77) and 64% (47/74) had antibodies reactive to R. rickettsii and E. chaffeensis, respectively, on IFA. Additionally, 5% (4/77) had antibodies reactive to E. canis, but not B. burgdorferi or A. phagocytophilum, on SNAP® 4Dx® ELISA; subsequent ...
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Experimental primary and secondary infections of domestic dogs with Ehrlichia ewingii.
Veterinary microbiology, 2011Co-Authors: Michael J. Yabsley, Ramaswamy Chandrashekar, Thomas P O'connor, Dustin S Adams, Susan E. LittleAbstract:In this study, the infection dynamics of Ehrlichia ewingii, causative agent of granulocytotropic ehrlichiosis in dogs and humans, was examined in experimentally infected dogs by using a combination of physical examination, hematologic and biochemical analyses, and molecular and serologic assays. For the experimental trials, blood from an E. ewingii-infected dog was inoculated intravenously into two naïve dogs and two dogs with prior experimental exposure to E. ewingii (both were negative for E. ewingii DNA by polymerase chain reaction (PCR) assay, but seropositive from initial infection 8 and 10 months prior to challenge). A negative control dog was inoculated with blood from a negative dog. The two primary infection dogs were positive for E. ewingii DNA on DPI 4, remained consistently positive until DPI 60, and were intermittently positive until the end of the study (DPI 144). The two primary infection dogs developed antibodies reactive to E. ewingii by DPI 28 and remained seropositive for the duration of the study. Primary infected dogs had intermittent fever, thrombocytopenia, and leukopenia and some dogs were hyperphosphatemic and/or had elevated ALP levels. The two challenge dogs were positive for E. ewingii DNA on DPI 4 and 18, which was similar to the primary infection dogs, but the duration of E. ewingii DNA detection was shorter. Also, the two challenged dogs did not develop pyrexia or show any hematologic or biochemical abnormalities. E. ewingii was successfully transmitted between dogs by Amblyomma americanum, but not Rhipicephalus sanguineus. This study provides data on the infection dynamics of E. ewingii in dogs during primary and challenge infections and suggests that prior exposure may lessen clinical disease during subsequent infections.
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Ehrlichia ewingii infection and exposure rates in dogs from the southcentral United States.
Veterinary parasitology, 2010Co-Authors: Susan E. Little, Thomas P O'connor, Julie Hempstead, Jill Saucier, Mason V Reichard, Katrina Meinkoth, James H Meinkoth, Blaine Andrews, Steve Ullom, Sidney A EwingAbstract:We used PCR and a novel serologic assay to determine infection and exposure rates to Ehrlichia ewingii in dogs from an area of northeast Oklahoma and northwest Arkansas where Amblyomma americanum ticks are abundant. Of 143 dogs assayed, 13 (9.1%) harbored E. ewingii by PCR and 64 (44.8%) had antibodies to E. ewingii detected using a peptide-based microtiter plate ELISA. Dogs were more likely (P=0.001) to be positive by PCR if sampled in August (30.8%) but no association was found between seropositive status and month of collection of sample (P>0.05). Additional testing revealed PCR evidence of Ehrlichia chaffeensis (4/143; 2.8%) and Anaplasma platys (5/143; 3.5%) as well as antibodies reactive to E. chaffeensis (25/143; 17.5%), Ehrlichia canis (2/143; 1.4%), and Anaplasma spp. (8/143; 5.6%). Testing of another 200 dogs from the area revealed additional PCR and/or serologic evidence of E. ewingii, E. canis, E. chaffeensis, and A. platys. None of the 343 dogs evaluated had evidence of Borrelia burgdorferi exposure. These data support the interpretation that E. ewingii may be the primary agent of canine ehrlichiosis in this region, and suggest that diagnostic evaluation of dogs suspected to have a tick-borne disease should include assays targeting this organism.
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NATURAL AND EXPERIMENTAL INFECTION OF WHITE-TAILED DEER (ODOCOILEUS VIRGINIANUS) FROM THE UNITED STATES WITH AN Ehrlichia SP. CLOSELY RELATED TO Ehrlichia RUMINANTIUM
Journal of wildlife diseases, 2008Co-Authors: Michael J. Yabsley, Amanda D. Loftis, Susan E. LittleAbstract:An Ehrlichia sp. (Panola Mountain [PM] Ehrlichia sp.) closely related to Ehrlichia ruminantium was recently detected in a domestic goat experimentally infested with lone star ticks (LSTs, Amblyomma americanum) collected from Georgia, USA. The infected goat exhibited pyrexia and mild clinical pathologic abnormalities consistent with ehrlichiosis. At least two other Ehrlichia species (Ehrlichia chaffeensis and Ehrlichia ewingii) are maintained in nature by a cycle involving LSTs as the primary vector and white-tailed deer (Odocoileus virginanus) as a known or suspected reservoir. To investigate the possibility that white-tailed deer are potential hosts of the PM Ehrlichia sp., whole blood samples collected from 87 wild deer from 2000 to 2002 were screened with a species-specific nested PCR assay targeting the citrate synthase gene. In addition, two laboratory-raised white-tailed deer fawns were each infested with 120 wild-caught LST adults from Missouri, USA, and blood samples were periodically collected an...
Michael J. Yabsley - One of the best experts on this subject based on the ideXlab platform.
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Experimental primary and secondary infections of domestic dogs with Ehrlichia ewingii.
Veterinary microbiology, 2011Co-Authors: Michael J. Yabsley, Ramaswamy Chandrashekar, Thomas P O'connor, Dustin S Adams, Susan E. LittleAbstract:In this study, the infection dynamics of Ehrlichia ewingii, causative agent of granulocytotropic ehrlichiosis in dogs and humans, was examined in experimentally infected dogs by using a combination of physical examination, hematologic and biochemical analyses, and molecular and serologic assays. For the experimental trials, blood from an E. ewingii-infected dog was inoculated intravenously into two naïve dogs and two dogs with prior experimental exposure to E. ewingii (both were negative for E. ewingii DNA by polymerase chain reaction (PCR) assay, but seropositive from initial infection 8 and 10 months prior to challenge). A negative control dog was inoculated with blood from a negative dog. The two primary infection dogs were positive for E. ewingii DNA on DPI 4, remained consistently positive until DPI 60, and were intermittently positive until the end of the study (DPI 144). The two primary infection dogs developed antibodies reactive to E. ewingii by DPI 28 and remained seropositive for the duration of the study. Primary infected dogs had intermittent fever, thrombocytopenia, and leukopenia and some dogs were hyperphosphatemic and/or had elevated ALP levels. The two challenge dogs were positive for E. ewingii DNA on DPI 4 and 18, which was similar to the primary infection dogs, but the duration of E. ewingii DNA detection was shorter. Also, the two challenged dogs did not develop pyrexia or show any hematologic or biochemical abnormalities. E. ewingii was successfully transmitted between dogs by Amblyomma americanum, but not Rhipicephalus sanguineus. This study provides data on the infection dynamics of E. ewingii in dogs during primary and challenge infections and suggests that prior exposure may lessen clinical disease during subsequent infections.
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Evaluation of peptide- and recombinant protein-based assays for detection of anti-Ehrlichia ewingii antibodies in experimentally and naturally infected dogs
American journal of veterinary research, 2010Co-Authors: Thomas P O'connor, Michael J. Yabsley, Yasuko Rikihisa, Qingming Xiong, Jill Saucier, Dustin S Adams, Daryn Daniluk, Brett A. Stillman, Regis Krah, Pedro Paulo Vissotto De Paiva DinizAbstract:Objective—To evaluate microtiter-plate format ELISAs constructed by use of different diagnostic targets derived from the Ehrlichia ewingii p28 outer membrane protein for detection of E ewingii antibodies in experimentally and naturally infected dogs. Sample Population—Serum samples from 87 kenneled dogs, 9 dogs experimentally infected with anti-E ewingii, and 180 potentially naturally exposed dogs from Missouri. Procedures—The capacities of the synthetic peptide and truncated recombinant protein to function as detection reagents in ELISAs were compared by use of PCR assay, western blot analysis, and a full-length recombinant protein ELISA. Diagnostic targets included an E ewingii synthetic peptide (EESP) and 2 recombinant proteins: a full-length E ewingii outer membrane protein (EEp28) and a truncated E ewingii outer membrane protein (EETp28) Results—A subset of Ehrlichia canis-positive samples cross-reacted in the EEp28 ELISA; none were reactive in the EESP and EETp28 ELISAs. The EESP- and EETp28-based E...
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NATURAL AND EXPERIMENTAL INFECTION OF WHITE-TAILED DEER (ODOCOILEUS VIRGINIANUS) FROM THE UNITED STATES WITH AN Ehrlichia SP. CLOSELY RELATED TO Ehrlichia RUMINANTIUM
Journal of wildlife diseases, 2008Co-Authors: Michael J. Yabsley, Amanda D. Loftis, Susan E. LittleAbstract:An Ehrlichia sp. (Panola Mountain [PM] Ehrlichia sp.) closely related to Ehrlichia ruminantium was recently detected in a domestic goat experimentally infested with lone star ticks (LSTs, Amblyomma americanum) collected from Georgia, USA. The infected goat exhibited pyrexia and mild clinical pathologic abnormalities consistent with ehrlichiosis. At least two other Ehrlichia species (Ehrlichia chaffeensis and Ehrlichia ewingii) are maintained in nature by a cycle involving LSTs as the primary vector and white-tailed deer (Odocoileus virginanus) as a known or suspected reservoir. To investigate the possibility that white-tailed deer are potential hosts of the PM Ehrlichia sp., whole blood samples collected from 87 wild deer from 2000 to 2002 were screened with a species-specific nested PCR assay targeting the citrate synthase gene. In addition, two laboratory-raised white-tailed deer fawns were each infested with 120 wild-caught LST adults from Missouri, USA, and blood samples were periodically collected an...
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ecological havoc the rise of white tailed deer and the emergence of amblyomma americanum associated zoonoses in the united states
Current Topics in Microbiology and Immunology, 2007Co-Authors: Christopher D. Paddock, Michael J. YabsleyAbstract:Two infectious diseases, and one presumably infectious disease, each vectored by or associated with the bite of the lone star tick ( Amblyomma americanum ), were identified and characterized by clinicians and scientists in the United States during the 1980s and 1990s. These three conditions—human monocytic (or monocytotropic) ehrlichiosis (HME), Ehrlichia ewingii ehrlichiosis, and southern tick-associated rash illness (STARI)—undoubtedly existed in the United States prior to this time. However,
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Ehrlichia ewingii infection in white tailed deer odocoileus virginianus
Emerging Infectious Diseases, 2002Co-Authors: Michael J. Yabsley, Vivien G Dugan, David E Stallknecht, Susan E. Little, Andrea S Varela, Cynthia M Tate, William R. DavidsonAbstract:Two closely related zoonotic Ehrlichiae, Ehrlichia chaffeensis and E. ewingii, are transmitted by Amblyomma americanum, the lone star tick. Because white-tailed deer (Odocoileus virginianus) are critical hosts for all mobile stages of A. americanum and are important vertebrate reservoirs of E. chaffeensis, we investigated whether deer may be infected with E. ewingii, a cause of granulocytotropic ehrlichiosis in humans and dogs. To test for E. ewingii infection, we used polymerase chain reaction and inoculation of fawns with whole blood from wild deer. Of 110 deer tested from 20 locations in 8 U.S. states, 6 (5.5%) were positive for E. ewingii. In addition, natural E. ewingii infection was confirmed through infection of captive fawns. These findings expand the geographic distribution of E. ewingii, along with risk for human infection, to include areas of Kentucky, Georgia, and South Carolina. These data suggest that white-tailed deer may be an important reservoir for E. ewingii.
Edward B Breitschwerdt - One of the best experts on this subject based on the ideXlab platform.
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Evidence for vertical transmission of Mycoplasma haemocanis, but not Ehrlichia ewingii, in a dog
Journal of veterinary internal medicine, 2019Co-Authors: Erin Lashnits, Sandra Grant, Brittany Thomas, Barbara A. Qurollo, Edward B BreitschwerdtAbstract:A 2-year-old female intact pregnant Beagle was evaluated after the owner surrendered her to a shelter. Prepartum and 2 months postpartum at the time of routine spay, the dam was whole-blood polymerase chain reaction (PCR) positive for Ehrlichia ewingii. She was also whole-blood PCR positive for Mycoplasma haemocanis prepartum and continuously for 5 months thereafter. The dam delivered 5 healthy puppies, 1 of which was whole-blood PCR positive for M. haemocanis. All 5 puppies had antibodies against Ehrlichia spp. at 1 month of age but not thereafter, and all puppies were Ehrlichia spp. PCR negative for 5 months of follow-up. Therefore, this study supports a potential role for vertical transmission in the maintenance of M. haemocanis in dogs as reservoir hosts. In contrast, in this case there was no evidence that E. ewingii was transmitted transplacentally or during the perinatal period.
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Clinicopathological findings in 41 dogs (2008-2018) naturally infected with Ehrlichia ewingii.
Journal of veterinary internal medicine, 2019Co-Authors: Barbara A. Qurollo, Edward B Breitschwerdt, Melissa J Beall, Ramaswamy Chandrashekar, Jesse Buch, Caroline B. Yancey, Alexander H. Caudill, Alaire ComynAbstract:Background Ehrlichia ewingii is the most seroprevalent Ehrlichia-infecting dogs in the southern and mid-western United States. Fever, lameness, and polyarthritis are commonly reported findings in dogs naturally infected with E. ewingii. Objectives To evaluate clinicopathologic findings in a population of dogs naturally infected with E. ewingii. Animals Forty-one dogs PCR positive for E. ewingii and PCR negative for other targeted vector-borne organisms. Methods Retrospective study. Clinical and clinicopathologic data including physical examination findings, CBC, serum biochemistry, urinalysis (UA), symmetric dimethylarginine (SDMA), and vector-borne disease diagnostic results were reviewed. Results Frequent clinical diagnoses other than ehrlichiosis (28/41; 68.3%) were renal disease (7/41; 17.1%) and immune-mediated hemolytic anemia (IMHA) (6/41; 14.6%). The most frequent physical examination finding was joint pain (14/41; 34.1%). Prominent hematologic and biochemical abnormalities included abnormal lymphocyte counts (22/36; 61.1%); neutrophilia (21/37; 56.8%); increased alkaline phosphatase (20/35; 57.1%) and alanine transaminase (14/35; 40%) activities; and increased SDMA concentration (11/34; 32.4%). Urinalysis abnormalities included proteinuria (20/27; 74%), most with inactive sediments (16/20; 80%). Dogs were seroreactive by Ehrlichia canis immunofluorescence assay (IFA; 17/39; 43.6%) and Ehrlichia ELISA (34/41; 82.9%). Seroreactivity by IFA for other vector-borne pathogens included Bartonella (1/39; 2.6%), Rickettsia rickettsii (spotted-fever group rickettsiae) (12/39; 30.8%), and Borrelia burgdorferi by ELISA (1/41; 2.4%). Conclusions and clinical importance Renal disease, IMHA, proteinuria, neutrophilia, abnormal lymphocytes, and increased liver enzyme activities were common in this group of E. ewingii-infected dogs. Studies are needed to determine if E. ewingii contributes to comorbidities or is a precipitating factor in clinical syndromes in persistently infected dogs.
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intravascular persistence of anaplasma platys Ehrlichia chaffeensis and Ehrlichia ewingii dna in the blood of a dog and two family members
Parasites & Vectors, 2014Co-Authors: Edward B Breitschwerdt, Barbara C Hegarty, Barbara A. Qurollo, Tais B Saito, Ricardo G Maggi, Lucas S Blanton, Donald H BouyerAbstract:Background: Anaplasmosis, caused by Anaplasma phagocytophilum and Anaplasma platys, and ehrlichiosis, caused by Ehrlichia chaffeensis, Ehrlichia ewingii, the "Panola Mountain Ehrlichia" and Ehrlichia muris-like pathogens have been identified as emerging tick borne infectious diseases in dogs and human patients. Persistent intravascular infection with these bacteria is well documented in dogs, but is less well documented in human beings. Methods: Serology and PCR targeting multiple microbial genes, followed by DNA sequencing, was used to test sequential blood samples. Tissue culture isolation was attempted in two laboratories. Results: A. platys, E. chaffeensis, and E. ewingii DNA was amplified from two Anaplasma and Ehrlichia seronegative family members and their dog, all lacking typical symptoms of anaplasmosis or ehrlichiosis. Following treatment with doxycycline, the dog and mother were Anaplasma and Ehrlichia spp. PCR negative. Conclusions: Sequential PCR testing provided molecular evidence supporting intravascular persistence of A. platys and Ehrlichia spp. in two humans and their dog. Diagnosticians and clinicians should consider the potential for co-infections due to these tick borne organisms.
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performance of a commercially available in clinic elisa for detection of antibodies against anaplasma phagocytophilum anaplasma platys borrelia burgdorferi Ehrlichia canis and Ehrlichia ewingii and dirofilaria immitis antigen in dogs
Javma-journal of The American Veterinary Medical Association, 2014Co-Authors: Brett A. Stillman, Edward B Breitschwerdt, Melissa J Beall, Brendon Thatcher, Blaine Andrews, Michael Monn, Paulette Foster, Susan J Little, Matt Eberts, Ramaswamy ChandrashekarAbstract:Objective—To evaluate the performance of an in-clinic ELISA designed for detection of heartworm antigen and antibodies against 5 tick-borne pathogens. Design—Validation study. Sample—1,601 serum or matched serum, plasma, and blood samples from dogs. Procedures—Samples were tested for Dirofilaria immitis (heartworm) antigen and antibodies against Anaplasma phagocytophilum, Anaplasma platys, Borrelia burgdorferi, Ehrlichia canis, and Ehrlichia ewingii by means of an in-clinic ELISA. Evaluation of assay sensitivity and specificity, agreement of results among sample types, and cross-reactivity of E canis antigens in the assay with anti–Ehrlichia chaffeensis antibodies in stored samples from experimentally infected dogs were performed at a reference laboratory. Field tests of the in-clinic ELISA were performed at 6 veterinary facilities. Results were compared with confirmatory test results. Results—Sensitivity and specificity of the in-clinic ELISA were > 89% for detection of antibodies against A phagocytophil...
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seroprevalence of Ehrlichia canis Ehrlichia chaffeensis and Ehrlichia ewingii in dogs in north america
Parasites & Vectors, 2012Co-Authors: Melissa J Beall, Edward B Breitschwerdt, Rick A Alleman, Leah A Cohn, Guillermo C Couto, Michael W Dryden, Lynn C Guptill, Cristina Iazbik, Stephen A Kania, Patty LathanAbstract:Background This study evaluated the exposure of dogs to three different Ehrlichia spp. in the south and central regions of the United States where vector-borne disease prevalence has been previously difficult to ascertain, particularly beyond the metropolitan areas.
William R. Davidson - One of the best experts on this subject based on the ideXlab platform.
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Ehrlichia ewingii infection in white tailed deer odocoileus virginianus
Emerging Infectious Diseases, 2002Co-Authors: Michael J. Yabsley, Vivien G Dugan, David E Stallknecht, Susan E. Little, Andrea S Varela, Cynthia M Tate, William R. DavidsonAbstract:Two closely related zoonotic Ehrlichiae, Ehrlichia chaffeensis and E. ewingii, are transmitted by Amblyomma americanum, the lone star tick. Because white-tailed deer (Odocoileus virginianus) are critical hosts for all mobile stages of A. americanum and are important vertebrate reservoirs of E. chaffeensis, we investigated whether deer may be infected with E. ewingii, a cause of granulocytotropic ehrlichiosis in humans and dogs. To test for E. ewingii infection, we used polymerase chain reaction and inoculation of fawns with whole blood from wild deer. Of 110 deer tested from 20 locations in 8 U.S. states, 6 (5.5%) were positive for E. ewingii. In addition, natural E. ewingii infection was confirmed through infection of captive fawns. These findings expand the geographic distribution of E. ewingii, along with risk for human infection, to include areas of Kentucky, Georgia, and South Carolina. These data suggest that white-tailed deer may be an important reservoir for E. ewingii.