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Ehrlichiosis is a tickborne illness that can lead to an increased risk of death without appropriate treatment. According to Centers for Disease Control and Prevention, there has been a rise in incidence. We present a case of an immunocompetent patient who reported tick removal after hiking. Chest imaging showed pulmonary vascular congestion, extensive bilateral airspace and bibasilar moderate-dependent pleural effusions. Transthoracic echocardiography showed moderate pulmonary hypertension with right ventricular systolic pressure of 56.3 mm Hg. Ehrlichia chaffeensis PCR testing came back positive. Doxycycline was started in the emergency department and continued for 14 days. The patient had a resolution of the pulmonary hypertension and decrease in tricuspid regurgitation. However, mild mitral regurgitation was persistent. The pulmonary hypertension may be caused by the patient's response to ehrlichiosis infection, but it may also be explained by the development of acute respiratory distress syndrome, which has been documented in multiple studies., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Ehrlichia chaffeensis is a bacterium belonging to the Anaplasmataceae family. In Mexico, only 2 species have been recorded in association with tick species and humans. The objective of the present study was to detect the presence of bacteria of the genus Ehrlichia in ticks collected from the Chamela-Cuixmala Biosphere Reserve, Jalisco, Mexico. The collected ticks were identified and analyzed individually by polymerase chain reaction to amplify a fragment of the Anaplasmataceae 16S rRNA gene and the Ehrlichia-specific dsb gene. A total of 204 ticks, corresponding to 5 species of Ixodidae and 1 of Argasidae, were collected from 147 mammals of 6 species and 4 orders; 57 ticks collected from vegetation were also included. Among the total ticks collected, 1.47% (3/204) was positive for Ehrlichia sp. DNA was obtained using the primers EHR 16SD and EHR 16SR for 16S rRNA and DSB-330 and DSB-728 for dsb. The positive samples corresponded to a larva (Amblyomma sp.) associated with Didelphis virginiana and 2 nymphs (Amblyomma cf. oblongoguttatum) infesting Nasua narica. None of the ticks collected from the vegetation tested positive for Ehrlichia sp. DNA on the basis of the 16S rRNA and dsb genes. The sequences from the larvae of Amblyomma sp. and the nymphs of A. cf. oblongoguttatum were similar to those of E. chaffeensis. The phylogenetic analysis inferred with maximum likelihood corroborated the identity as E. chaffeensis. Although the role of these tick species as vectors of E. chaffeensis is still undetermined, the presence of infected ticks in the area indicates a potential zoonotic risk., (© The Author(s) 2024. Published by Oxford University Press on behalf of Entomological Society of America.)

Ehrlichiosis, caused by Gram-negative bacteria of the genus Ehrlichia, is considered an emerging infectious disease due to the increasing number of reported cases. Symptoms are non-specific and occur within 1 to 2 weeks following the bite of an infected tick. Confirmatory laboratory diagnostic methods vary in sensitivity and specimen requirements, which can lead to delayed diagnosis. PCR testing serves as an efficient approach to Ehrlichia confirmation in the acute stage of illness. Published assays have been effectively used to detect human ehrlichiosis at limit of detections ranging from 10 to 50 genomic copies (GC) of Ehrlichia DNA. With the discovery of new species capable of human infection, we wanted to develop assays that are sensitive and encompass a wide range of Ehrlichia. Here we developed and validated two sensitive and specific real-time PCR assays (PanE1 and PanE2) for the detection of Ehrlichia species, as well as two real-time PCR assays (ECh2 and ECh4) for the detection of Ehrlichia chaffeensis, specifically. The limit of detection was determined to be 10 GC per reaction with 100% confidence, and as little as 1 GC with lower efficiencies. Accuracy was assessed at 100% correlation. Specificity from exclusivity testing demonstrated that neither the Ehrlichia species assays (n = 60), nor the E. chaffeensis specific assays (n = 64) had cross reactivity with near neighbors or environmental bacteria. A positive predictive value of 100% and a negative predictive value of ≥93% was determined by evaluating banked clinical specimens from 62 patients with the assays. These real-time PCR assays are effective tools to detect human Ehrlichia species during the acute stage of illness. Early detection of Ehrlichia infection by these real-time PCR assays can facilitate diagnosis and treatment., (Copyright © 2021. Published by Elsevier B.V.)

We report a large cohort of pediatric patients with human monocytic ehrlichiosis (HME), enabling an estimated incidence of secondary hemophagocytic lymphohistiocytosis (HLH) in hospitalized children with HME. Among 49 children with PCR-confirmed Ehrlichia infection, 8 (16%) met current criteria for HLH. Those with HLH had more significant hematologic abnormalities and longer durations from symptom onset to admission and definitive anti-infective therapy. Among these eight, three received chemotherapy plus doxycycline, one of whom died; the other five were treated with doxycycline without chemotherapy, and all survived without HLH recurrence. Our findings demonstrate that antimicrobial therapy alone can successfully resolve Ehrlichia-associated HLH., (© 2020 Wiley Periodicals, Inc.)

Increasing amount of data attest that (in the context of vector-borne infections) birds are not only important as hosts of blood-sucking arthropod vectors, but also as reservoirs of vector-borne pathogens. From 2015 to 2019 cadavers of 100 birds (from 45 species, nine orders) were collected in Hungary, and their organs were screened for DNA from a broad range of vector-borne bacteria with PCR and sequencing. Molecular analyses revealed the presence of Anaplasmataceae, and sequencing identified bacteria closely related to Neorickettsia helminthoeca and Ehrlichia chaffeensis in a Eurasian teal (Anas crecca) and a song thrush (Turdus philomelos), respectively. All samples were PCR negative for rickettsiae, borreliae, Francisella and Coxiella spp., as well as for piroplasms. To our knowledge, this is the first report of a Neorickettsia and an Ehrlichia sp., which belong to the phylogenetic groups of N. helminthoeca and E. chaffeensis, respectively, from Europe. The potential presence of these two vector-borne bacteria needs to be taken into account during future studies on the eco-epidemiology of Anaplasmataceae in Europe.

Tick-borne illness has been increasingly on the rise, since the first human case was reported in the late 1980s. Ehrlichia chaffeensis is one of the most common reported causes of tick-borne illness, particularly in the southern states of the United States. The clinical picture presents as a paradigm to the clinician, often missing the diagnosis without an appropriate history being taken and sometimes mistreated for other conditions. With the number of cases on the rise, new manifestations and clinical presentations due to E chaffeensis continue to be reported. Our case report is one such case in a 46-year-old male from Arkansas, with known exposure to multiple tick bites who presented with classical symptoms and laboratory values of tick-borne illness leading to atrial flutter. This unusual manifestation of atrial flutter due to tick-borne illness is rare and poorly understood. Further studies on tick-borne illness due to E chaffeensis may be needed to understand the systemic causes of the bacteria. In addition, in our case report, we bring to attention the standard presentation (symptoms, signs, and laboratory values) of tick-borne illness due to E chaffeensis along with the current standard for diagnosis and treatment.

Ehrlichiosis is a disease transmitted by tick's bite that affect dogs and humans caused by the species Ehrlichia canis and E. chaffeensis, respectively. These bacteria are obligated intracellular gram negatives, with a cocoid to pleomorph aspect and can infect monocytes and trigger symptoms such as high fever, anorexia, thrombocytopenia, hemorrhages, anemia, and some serious problems such as splenomegaly, hepatomegaly and meningitis. There are several diagnostic tests for ehrlichiosis such as the hematological ones that evaluate the morphology of the monocytes in search of morulae; serological tests that includes the search of anti-Ehrlichia antibodies, although they might be limited due to cross reaction with other species. In other hand, the culture of Ehrlichia species is an effective method to obtain antigens and even develop indirect immunofluorescence assays (IFA). The polymerase chain reaction offers a definitive diagnosis associated to the use of genus-specific and species-specific primers, as well as its increased sensibility and specificity, compared to the others methods. Thus, in this review, we will discuss various methods applied to the diagnosis of this disease, as well as the advantages and disadvantages that these present.

Twenty-five white-tailed deer (Odocoileus virginianus yucatanensis) (WTD), 4 mazama deer (Mazama temama) (MD), and the ticks they host in Yucatan, Mexico were sampled to run a molecular survey for tick-borne rickettsial agents. The prevalence of rickettsial agents was 20% in WTD (5/25) and 50% in MD (2/4). When sequencing the nested PCR products, E. chaffeensis, A. phagocytophilum and A. odocoilei, were identified as single infection or coinfecting cervids. None of the cervid samples were positive for E. ewingii, E. canis, nor Rickettsia spp. Overall, 355 individual ticks were collected. Species identified based on adult stages infesting cervids included Amblyomma mixtum, A. parvum, A. cf. oblongoguttatum, Ixodes affinis, Rhipicephalus microplus, R. sanguineus sensu lato, and Haemaphysalis juxtakochi. Rhipicephalus microplus was the tick species most commonly found infesting cervids with a frequency of 28.4%, and intensity of 25.2 ticks per animal. A pool of Amblyomma cf. oblongoguttatum adults and one of Amblyomma spp. nymphs were positive for E. canis and E. chaffeensis, respectively. None of the studied tick pools were positive for E. ewingii, A. phagocytophilum, nor R. rickettsii. To the best of our knowledge, this study is the first to report the prevalence of rickettsial agents in WTD and MD in Mexico. Our molecular study is the first to report the detection of E. chaffeensis, A. phagocytophilum, and A. odocoilei in MD in Mexico. The molecular detection of E. chaffeensis, A. phagocytophilum, and A. odocoilei in deer, and E. chaffeensis in Amblyomma spp. nymphs reported here raises the concern for the risk of human exposure to tick-borne rickettsial pathogens. Our findings highlight the need to apply the "One Health" approach to study ticks and tick-borne diseases. This science-based information could be used by state public-health programs to assess the risk for exposure to tick-borne Anaplasmataceae in Yucatan, Mexico., (Copyright © 2018 Elsevier GmbH. All rights reserved.)

Ehrlichia chaffeensis (Rickettsiales: Anaplasmatacae), an understudied bacterial pathogen emerging in the eastern United States, is increasing throughout the range of its vector, the lone star tick [Amblyomma americanum, L. (Acari: Ixodidae)]. To mitigate human disease risk, we must understand what factors drive E. chaffeensis prevalence. Here, we report patterns of E. chaffeensis prevalence in southeastern Virginia across 4 yr and ask how seasonal weather patterns affect variation in rates of E. chaffeensis occurrence. We collected A. americanum nymphs at 130 plots across southeastern Virginia in 2012, 2013, 2015, and 2016, and used polymerase chain reaction and gel electrophoresis to test for the presence of E. chaffeensis DNA. Prevalence estimates varied among years, ranging from 0.9% to 3.7%, and persistence of E. chaffeensis occurrence varied across space, with some sites never testing positive, and one site testing positive every year. Using generalized linear mixed-effects models, we related E. chaffeensis occurrence to temperature, humidity, vapor-pressure deficit, and precipitation during seasons up to 21 mo prior to sampling. Surprisingly, all support was lent to a positive effect of temperature during the previous fall and winter (i.e., prior to the nymphs' hatching), which we hypothesize to influence reservoir host population dynamics through changes to mortality or natality. Although further work is necessary to truly elucidate the mechanisms at play, our study shows E. chaffeensis distribution to be very dynamic across multiple dimensions, demanding broad concerted monitoring efforts that can consider both space and time.

The growing risk of transmission of tick-borne zoonotic pathogens to humans in Ontario, Canada, warrants investigations into regional tick distribution, tick burdens of local peridomestic animals, and prevalence of tick-borne pathogens. The objectives of this study were to investigate the geographic distribution and magnitude of tick infestations in opportunistically sampled mammalian wildlife and companion animals (i.e., dogs) in southern Ontario and to test these ticks for evidence of zoonotic tick-borne pathogens. Ticks collected from wildlife carcasses, live-trapped wildlife and companion animals (2015-2016), as well as wildlife diagnostic cases (2011-2013), were identified to species and life stage. Ixodes scapularis ticks were tested by real-time PCR for Anaplasma phagocytophilum, Babesia microti, Borrelia miyamotoi and Borrelia burgdorferi sensu stricto (s.s.). Amblyomma americanum ticks were tested for Ehrlichia chaffeensis. A total of 1687 ticks of six species were collected from 334 animals, including 224 raccoons (n = 1381 ticks) and 50 dogs (n = 67 ticks). The most common tick species collected from parasitized raccoons were Ixodes texanus (n = 666 ticks) and Dermacentor variabilis (n = 600 ticks), which were removed from 58.5% (median: 2 ticks; range: 1-36) and 49.1% (median: 2 ticks; range: 1-64) of raccoons, respectively. Of I. scapularis tested, 9.3% (4/43) were positive for Bo. burgdorferi s.s. and 2.3% (1/43) for A. phagocytophilum. These results reveal that numerous tick species parasitize common, peridomestic wildlife and that at least two zoonotic, tick-borne pathogens circulate in southern Ontario. Host-tick vector-pathogen dynamics should continue to be monitored in the face of global climate change, landscape alterations and expanding human populations., (Crown Copyright © 2018. Published by Elsevier GmbH. All rights reserved.)

Ehrlichiosis is a rare tickborne illness that can manifest from an asymptomatic, self-limiting disease to a severe presentation with encephalopathy and renal failure. Ehrlichiosis is diagnosed largely based on patient history with confirmatory tests including peripheral blood smear, serology and PCR. Empiric treatment is warranted in patients with suspected tick bites as a delay in treatment can result in multiorgan failure. We discuss a case of ehrlichiosis that presented with the classic pentad of thrombotic thrombocytopenic purpura (TTP). A history of a tick bite was elicited and intravenous doxycycline 100 mg two times a day was initiated. Tick panel results revealed a positive Ehrlichia chaffeensis IgG and IgM titres, consistent with human monocytic ehrlichiosis. Autoimmune workup and antibodies to Borreliaburgdorferi were negative, and ADAMTS13 activity assay results were inconsistent with TTP. The patient completed 14 days of intravenous doxycycline and had an uneventful recovery., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2018. No commercial re-use. See rights and permissions. Published by BMJ.)

We present a case of possible transfusion-transmitted Ehrlichia chaffeensis infection in a heavily transfused cord blood transplant recipient, resulting in severe infection and graft loss. Transfusion-transmitted, vector-borne infections in immunocompromised individuals can have severe consequences, and should be considered in hospitalized patients receiving blood products with unexplained fever or sepsis., (© 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Ticks are an important but under recognized parasitic threat to cats in many areas of the United States. To characterize the species and stages of ticks most commonly recovered from cats and determine the prevalence of disease agents in the ticks, we conducted a survey of ticks removed from cats at veterinary practices in 18 states from April 2016-June 2017. A total of 796 ticks were submitted from 332 cats from 41 different veterinary practices. A single tick was submitted from the majority of cats, with a mean infestation intensity of 2.4 (range 1-46). The most common tick was Ixodes scapularis, accounting for 422/796 (53.0%) ticks submitted, followed by Amblyomma americanum (224/796; 28.1%) and Dermacentor variabilis (131/796; 16.5%); a few I. pacificus, I. banksi, D. occidentalis, A. maculatum, Rhipicephalus sanguineus, and Otobius megnini were also submitted. A majority of ticks were adults (593/796; 74.5%); females predominated in all adult tick submissions including I. scapularis (277/327; 84.7% female), A. americanum (66/128; 51.6% female), and D. variabilis (75/126; 59.5% female). Immature ticks included 186 nymphs and 17 larvae and were primarily I. scapularis and A. americanum. Adult I. scapularis were most reported to be attached to the dorsal head and neck; A. americanum to the abdomen and perianal region; and D. variabilis to the back and ear. Ticks were collected in every month; the largest number of submissions were in May and June (42.5% of ticks) and October and November (35.9% of ticks). Adults of I. scapularis were most commonly submitted October through December, A. americanum March through June, and D. variabilis May through July. Cats with ticks were predominantly male (58.8%) and altered (76.2%), and most reportedly spent >30% of time outdoors, although 64/294 (21.8%) for which lifestyle estimates were provided were reported to live primarily (≤30% of time outside; n = 54) or entirely (100%; n = 10) indoors. Assay of ticks removed from cats revealed I. scapularis were infected with Borrelia burgdorferi (25.7%) and Anaplasma phagocytophilum (4.4%); A. americanum were infected with Ehrlichia chaffeensis (1.3%); and D. variabilis were infected with spotted fever group Rickettsia spp. (3.1%). No ticks in this study tested positive for Cytauxzoon felis. Pet cats, including those that live primarily indoors, are at risk of tick infestation, potentially exposed to tick-borne disease agents, and would benefit from routine tick control., (Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.)

The aim of this work was to describe two novel strains of Ehrlichia associated to Amblyomma tigrinum from Argentina. Molecular detection of agents belonging to the family Anaplasmataceae was performed targeting three different loci: 16S rRNA gene, dsb gene and a fragment of groESL heat shock operon. The results have shown that two different strains of Ehrlichia sp. associated to A. tigrinum are circulating in peri-urban areas of Argentina. The Ehrlichia strain detected in ticks from San Luis Province, named as Ehrlichia sp. strain San Luis, is closely related to the Ehrlichia chaffeensis. The novel Ehrlichia strain detected in Córdoba Province, named as Ehrlichia sp. strain Córdoba, is phylogenetically related to three Ehrlichia strains from Brazil, two of them isolated from wild carnivorous and the third one isolated from horse. Even though Ehrlichia sp. strain Córdoba was clustered with the three Ehrlichia strains from Brazil, the genetic similarity was too low to consider them as the same taxonomic entity. Blood samples of dogs were positive to Anaplasma platys. The association of these two novel strains with A. tigrinum has epidemiological relevance because adult stages of this tick species are common parasite of dogs in rural and peri-urban areas and they are aggressive to humans. The presence of these two novel Ehrlichia strains implies a potential epidemiological risk in Argentina because the species of the genus Ehrlichia are known to be pathogenic to both domestic mammals and humans., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Borrelia miyamotoi (Bm) is a recently emerging bacterial agent transmitted by several species of ixodid ticks. Diagnosis of Bm infection can be challenging, as the organism is not easily cultivable. We have developed and validated a multiplex real-time PCR to simultaneously identify Bm infection and the agents causing human granulocytic anaplasmosis and human monocytic ehrlichiosis, Anaplasma phagocytophilum and Ehrlichia chaffeensis, respectively. The assay is 100% specific; highly sensitive, detecting 11 gene copies of Bm DNA in both whole blood and cerebral spinal fluid; and provides rapid results in less than two hours. A retrospective study of 796 clinical specimens collected between the years 2012 and 2014 and a prospective study of 366 clinical specimens were performed utilizing this novel assay to evaluate the frequency of Bm infection in New York State (NYS). Eight clinical specimens (1%) were found to be positive for Bm, 216 were positive for A. phagocytophilum, and 10 were positive for E. chaffeensis. Additionally, we tested 411 I. scapularis ticks collected in NYS during 2013 and 2014 in a separate multiplex real-time PCR to determine the prevalence of Bm, A. phagocytophilum, Borrelia burgdorferi s.s., and Borrelia species. Our results indicated rates of 1.5%, 27%, 19.7%, and 8.8% respectively. The ability to monitor both the frequency and geographic distribution of Bm cases and the prevalence and geographic distribution of Bm in ticks will help create a better understanding of this emerging tick-borne pathogen., (Published by Elsevier GmbH.)

During infection, some intracellular pathogenic bacteria use a dedicated multiprotein complex known as the type IV secretion system to deliver type IV effector (T4E) proteins inside the host cell. These T4Es allow the bacteria to evade host defenses and to subvert host cell processes to their own advantage. Ehrlichia chaffeensis is a tick-transmitted obligate intracellular pathogenic bacterium, which causes human monocytic ehrlichiosis. Using comparative whole genome analysis, we identified the relationship between eight available E. chaffeensis genomes isolated from humans and show that these genomes are highly conserved. We identified the candidate core type IV effectome of E. chaffeensis and some conserved intracellular adaptive strategies. We assigned the West Paces strain to genetic group II and predicted the repertoires of T4Es encoded by E. chaffeensis genomes, as well as some putative host cell targets. We demonstrated that predicted T4Es are preferentially distributed in gene sparse regions of the genome. In addition to the identification of the two known type IV effectors of Anaplasmataceae , we identified two novel candidates T4Es, ECHLIB_RS02720 and ECHLIB_RS04640, which are not present in all E. chaffeensis strains and could explain some variations in inter-strain virulence. We also identified another novel candidate T4E, ECHLIB_RS02720, a hypothetical protein exhibiting EPIYA, and NLS domains as well as a classical type IV secretion signal, suggesting an important role inside the host cell. Overall, our results agree with current knowledge of Ehrlichia molecular pathogenesis, and reveal novel candidate T4Es that require experimental validation. This work demonstrates that comparative effectomics enables identification of important host pathways targeted by the bacterial pathogen. Our study, which focuses on the type IV effector repertoires among several strains of E. chaffeensis species, is an original approach and provides rational putative targets for the design of alternative therapeutics against intracellular pathogens. The collection of putative effectors of E. chaffeensis described in our paper could serve as a roadmap for future studies of the function and evolution of effectors.

Tick-borne bacteria, Ehrlichia canis, Anaplasma platys, and Ehrlichia chaffeensis are significant pathogens of dogs worldwide, and coinfections of E. canis and A. platys are common in dogs on the Caribbean islands. We developed and evaluated the performance of a multiplex bead-based assay to detect antibodies to E. canis, A. platys, and E. chaffeensis peptides in dogs from Grenada, West Indies, where E. canis and A. platys infections are endemic. Peptides from outer membrane proteins of P30 of E. canis, OMP-1X of A. platys, and P28-19/P28-14 of E. chaffeensis were coupled to magnetic beads. The multiplex peptide assay detected antibodies in dogs experimentally infected with E. canis and E. chaffeensis, but not in an A. platys experimentally infected dog. In contrast, the multiplex assay and an in-house enzyme-linked immunosorbent assay (ELISA) detected A. platys antibodies in naturally infected Grenadian dogs. Following testing of 104 Grenadian canine samples, multiplex assay results had good agreement with commercially available ELISA and immunofluorescent assay for E. canis antibody-positive dogs ( K values of 0.73 and 0.84), whereas A. platys multiplex results had poor agreement with these commercial assays ( K values of -0.02 and 0.01). Prevalence of seropositive E. canis and A. platys Grenadian dogs detected by the multiplex and commercial antibody assays were similar to previous reports. Although the multiplex peptide assay performed well in detecting the seropositive status of dogs to E. canis and had good agreement with commercial assays, better antigen targets are necessary for the antibody detection of A. platys.

We evaluated Amblyomma americanum (lone star tick) and Dermacentor variabilis (American dog tick) in northeast Missouri for the presence of Borrelia, Ehrlichia, and Rickettsia bacteria. We collected actively questing ticks from four sites within Adair County, Missouri. A total of 15,162 ticks were collected, of which 13,980 were grouped in 308 pools (lone star ticks, 288 pools; American dog ticks, 20 pools) and tested for presence/absence of bacteria using polymerase chain reaction. Infection rates were calculated as the maximum likelihood estimation (MLE) with 95% confidence intervals (CI). Of the 308 pools tested, 229 (74.4%) were infected with bacteria and the overall MLE of the infection rate per 100 ticks was calculated as 2.9% (CI 2.61-3.21). Infection rates varied among life stages, 28.6% (CI 23.89-33.97) in adults, 7.0% (CI 5.10-9.86) in nymphs, and 1.0% (CI 0.75-1.20) in larvae. In the 116 adult lone star pools, infection rates were calculated for Borrelia lonestari (1.4%), Borrelia spp. (2.7%), Ehrlichia chaffeensis (6.1%), Ehrlichia ewingii (3.3%), Rickettsia amblyommii (18.3%), and Rickettsia montanensis (0.4%). Infection rates for the 52 nymphal lone star pools were calculated as B. lonestari (1.03%), Borrelia spp. (0.40%), E. chaffeensis (2.02%), E. ewingii (0.24%), and R. amblyommii (2.70%). In the 20 adult American dog tick pools, infection rates were determined as E. chaffeensis (9.47%), E. ewingii (5.47%), and R. montanensis (8.06%). Eight Borrelia samples were sequenced with five 99-100% identical to B. burgdorferi (s.l.) and three 99% identical to B. lonestari. Eight samples were sequenced for E. chaffeensis (all 99-100% identical) and one sample was sequenced for E. ewingii (99% identical). Seven samples were sequenced for Rickettsia and three were 99% identical to R. montanensis and four were 100% identical to R. amblyommii. This study demonstrates B. lonestari, E. chaffeensis, E. ewingii, R. amblyommii, and R. montanensis in northeast Missouri ticks for the first time. Understanding the presence and epidemiology of these causative (E. chaffeensis and E. ewingii) and suspected (B. lonestari and R. amblyommii) agents in Missouri should increase awareness of potential tick-borne disease in the medical community., (Copyright © 2016 Elsevier GmbH. All rights reserved.)

We present a previously healthy 16-year-old male with ehrlichiosis-induced aseptic meningitis and subsequent second-degree heart block.

Panola Mountain Ehrlichia (PME) has been suggested as an emerging pathogen of humans and dogs. Domestic goats and white-tailed deer (Odocoileus virginianus) are also susceptible and likely serve as reservoirs. Experimentally, both the lone star tick (Amblyomma americanum (L.)) and the Gulf Coast tick (Amblyomma maculatum Koch) can transmit PME among deer and goats. In the current study, we detected PME in adult wild-caught A. maculatum from the United States and Amblyomma variegatum (F.) from the Caribbean and Africa. This significantly expands the range, potential tick vectors, and risk for exposure to PME., (© The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Tick-borne diseases cause substantial morbidity throughout the United States, and North Carolina has a high incidence of spotted fever rickettsioses and ehrlichiosis, with sporadic cases of Lyme disease. The occupational risk of tick-borne infections among outdoor workers is high, particularly those working on publicly managed lands. This study identified incident tick-borne infections and examined seroconversion risk factors among a cohort of North Carolina outdoor workers. Workers from the North Carolina State Divisions of Forestry, Parks and Recreation, and Wildlife (n = 159) were followed for 2 years in a randomized controlled trial evaluating the effectiveness of long-lasting permethrin-impregnated clothing. Antibody titers against Rickettsia parkeri, Rickettsia rickettsii, "Rickettsia amblyommii," and Ehrlichia chaffeensis were measured at baseline (n = 130), after 1 year (n = 82), and after 2 years (n = 73). Titers against Borrelia burgdorferi were measured at baseline and after 2 years (n = 90). Baseline seroprevalence, defined as indirect immunofluorescence antibody titers of 1/128 or greater, was R. parkeri (24%), R. rickettsii (19%), "R. amblyommii" (12%), and E. chaffeensis (4%). Incident infection was defined as a fourfold increase in titer over a 1-year period. There were 40 total seroconversions to at least one pathogen, including R. parkeri (n = 19), "R. amblyommii" (n = 14), R. rickettsii (n = 9), and E. chaffeensis (n = 8). There were no subjects whose sera were reactive to B. burgdorferi C6 antigen. Thirty-eight of the 40 incident infections were subclinical. The overall risk of infection by any pathogen during the study period was 0.26, and the risk among the NC Division of Forest Resources workers was 1.73 times that of workers in other divisions (95% confidence interval [CI]: 1.02, 2.92). The risk of infection was lower in subjects wearing permethrin-impregnated clothing, but not significantly (risk ratio = 0.81; 95% CI: 0.47, 1.39). In summary, outdoor workers in North Carolina are at high risk of incident tick-borne infections, most of which appear to be asymptomatic.

The lone star tick, Amblyomma americanum (L.) (Acari: Ixodidae), is established in southeastern Nebraska yet the prevalence of tick-associated microorganisms is not known. An initial PCR-based analysis for Ehrlichia chaffeensis, Ehrlichia ewingii, and Borrelia infection in host-seeking adult ticks collected in southeast Nebraska was conducted. A total of 251 adult ticks collected in six sites in southeast Nebraska were tested. E. chaffeensis, E. ewingii, and Borrelia spp. were present, and the prevalence of each was approximately 1.6%. This study demonstrates that Ehrlichia spp. are present in Nebraska lone star tick populations., (Copyright © 2015 Elsevier GmbH. All rights reserved.)

Little data are available on the prevalence and transmission of vector-borne diseases in stray dogs in Peninsular Malaysia. This study was designed to determine the occurrence of vector-borne pathogens in Malaysian stray dogs using serological and molecular approaches. In total, 48 dog blood samples were subjected to serological analysis using SNAP 4Dx kit (IDEXX Laboratories, Westbrook, ME). The presence of Ehrlichia and Anaplasma DNA in the dog blood samples and Rhipicephalus sanguineus (Latreille) ticks was detected using nested polymerase chain reaction assays. Positive serological findings against Ehrlichia canis and Anaplasma phagocytophilum were obtained in 17 (39.5%) and four (9.3%) of 43 dog samples, respectively. None of the dog blood samples were positive for Borrelia burgdorferi and Dirofilaria immitis. DNA of E. canis and A. phagocytophilum was detected in 12 (25.5%) and two (4.3%) of 47 dog blood samples, and 17 (51.5%) and one (3.0%) of 33 R. sanguineus ticks, respectively. Additionally, DNA of Ehrlichia spp. closely related to Ehrlichia chaffeensis was detected in two (6.1%) R. sanguineus ticks. This study highlights the prevalence of anaplasmosis and ehrlichiosis in dogs in Malaysia. Due to the zoonotic potential of Ehrlichia and Anaplasma spp., appropriate measures should be instituted for prevention and control of vector-borne diseases in dogs., (© The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Background: Wildlife is an important natural reservoir of many tick-borne pathogens. These agents have an impact on the health of humans and other animals throughout the world. This study was conducted to determine whether and what species of tick-borne agents had infected wild birds collected from Guangxi, in southwest China., Findings: Liver samples obtained from wild birds were tested for the presence of tick-borne pathogens by PCR assays and sequencing of the flagellin and 16S rRNA genes. Borrelia garinii was detected in Eurasian collared doves (2/57, 3.5%) from among the 95 wild birds. Anaplasma phagocytophilum was detected in Eurasian collared doves (2/57, 3.5%) and Eurasian eagle owls (2/13, 15.4%). Ehrlichia chaffeensis and a potential novel Anaplasma sp. were identified in Common pheasant (1/12, 8.3%). These results suggest the involvement of birds in the cycle of tick-borne diseases. To our knowledge, this is the first study to document infection of birds with B. garinii, A. phagocytophilum, E. chaffeensis and the novel Anaplasma sp. in China., Conclusions: Tick-borne zoonotic bacteria B. garinii, A. phagocytophilum and E. chaffeensis, and a potential novel Anaplasma sp., were identified in wild birds in southwest China. The presence of these agents in birds increases the potential spread over long distances and the risk of transmission of infection from birds to new hosts, including humans.

Although scrub typhus and murine typhus are well-described tropical rickettsial illnesses, especially in Southeast Asia, only limited evidence is available for rickettsia-like pathogens contributing to the burden of undifferentiated febrile illness. Using commercially available kits, this study measured immunoglobulin G (IgG) antibody seroprevalence for Coxiella burnetii, Ehrlichia chaffeensis, Bartonella henselae, Anaplasma phagocytophilum, and spotted fever group rickettsiae (SFGR) in 375 patients enrolled in undifferentiated febrile illness studies at Chiangrai (northern Thailand) and Mae Sot (Thai-Myanmar border). Ehrlichia and SFGR were the most common causes of IgG seropositivity. A distinct relationship between age and seropositivity was found in Chiangrai with acquisition of IgG titers against Ehrlichia, Bartonella, Anaplasma, and SFGR in young adulthood, suggesting cumulative exposure to these pathogens. At Mae Sot, high early IgG titers against Ehrlichia and SFGR were common, whereas Anaplasma and Bartonella IgG titers increased at 50-60 years. Q fever associated with low IgG positivity at both study sites, with significantly higher prevalence at 30 years of age in Chiangrai. These data suggest that other rickettsial illnesses could contribute to the burden of febrile illness in Thailand and possibly adjacent regions. Improved diagnostics and better understanding of antibody longevity and cross-reactivity will improve identification and management of these easily treatable infectious diseases.

The current status of tick-borne diseases in the southeastern United States is challenging to define due to emerging pathogens, uncertain tick/host relationships, and changing disease case definitions. A golf-oriented retirement community on the Cumberland Plateau in Tennessee experienced an ehrlichiosis outbreak in 1993, prompting efforts to reduce the local tick population using '4-Poster' acaricide devices targeting white-tailed deer (Odocoileus virginianus). In 2009, the prevalence of Ehrlichia spp. in questing ticks was surveyed in the area and compared to a Tennessee state park where acaricide had not been applied. The range of wildlife hosts that immature Amblyomma americanum fed upon and the role that these hosts may play in pathogen dynamics were investigated using a reverse line blot (RLB) bloodmeal analysis technique. Amblyomma americanum was by far the most common tick species in both study areas (>99% of ticks collected). Of 303 adult and nymphal A. americanum tested at the retirement community, six were positive for Ehrlichia chaffeensis (2.0%), 16 were positive for E. ewingii (5.3%), and six were positive for Panola Mountain Ehrlichia (2.0%). This is the first confirmation of Panola Mountain Ehrlichia in A. americanum from the state of Tennessee. The 9.3% prevalence of Ehrlichia spp. in ticks from the retirement community was similar to that detected at the state park site (5.5%), suggesting that the 4-Poster treatment had not been sufficient to reduce Ehrlichia spp. cycling in the tick population. At both study sites, A. americanum fed on a wide range of mammal and bird species, with a minority of detectable bloodmeals coming from deer. Of the Ehrlichia-infected nymphs with positive bloodmeal identification, none fed on deer, indicating that multiple vertebrate species are contributing to sylvatic maintenance of Ehrlichia spp. at these sites. This highlights the difficulty of attempting to reduce the risk of tick-borne disease through host-targeted interventions alone., (Copyright © 2015 Elsevier GmbH. All rights reserved.)

Ehrlichia chaffeensis, transmitted from Amblyomma americanum ticks, causes human monocytic ehrlichiosis. It also infects white-tailed deer, dogs and several other vertebrates. Deer are its reservoir hosts, while humans and dogs are incidental hosts. E. chaffeensis protein expression is influenced by its growth in macrophages and tick cells. We report here infection progression in deer or dogs infected intravenously with macrophage- or tick cell-grown E. chaffeensis or by tick transmission in deer. Deer and dogs developed mild fever and persistent rickettsemia; the infection was detected more frequently in the blood of infected animals with macrophage inoculum compared to tick cell inoculum or tick transmission. Tick cell inoculum and tick transmission caused a drop in tick infection acquisition rates compared to infection rates in ticks fed on deer receiving macrophage inoculum. Independent of deer or dogs, IgG antibody response was higher in animals receiving macrophage inoculum against macrophage-derived Ehrlichia antigens, while it was significantly lower in the same animals against tick cell-derived Ehrlichia antigens. Deer infected with tick cell inoculum and tick transmission caused a higher antibody response to tick cell cultured bacterial antigens compared to the antibody response for macrophage cultured antigens for the same animals. The data demonstrate that the host cell-specific E. chaffeensis protein expression influences rickettsemia in a host and its acquisition by ticks. The data also reveal that tick cell-derived inoculum is similar to tick transmission with reduced rickettsemia, IgG response and tick acquisition of E. chaffeensis.

Amblyomma americanum is the most commonly encountered tick species in southeastern Virginia, representing approximately 95% of the human-biting tick population in this area. Here we investigated the prevalence of Ehrlichia chaffeensis and Ehrlichia ewingii in questing Amblyomma americanum and Dermacentor variabilis ticks collected from multiple sites in southeastern Virginia from 2010 to 2011. Although both Ehrlichia species were detected in Amblyomma americanum, no evidence of either pathogen was found in Dermacentor variabilis. Prevalence of E. chaffeensis varied by location, ranging from 0 to 5.08% among Amblyomma americanum populations. Ehrlichia ewingii prevalence was slightly higher, ranging from 0 to 8.20% among A. americanum populations. We conclude that both pathogens are established in southeastern Virginia A. americanum populations, and that although there are no apparent temporal trends in Ehrlichia prevalence, there is variation among locations, suggesting the potential for disease hotspots., (Copyright © 2014 Elsevier GmbH. All rights reserved.)

Ehrlichia chaffeensis, the etiologic agent of human monocytic ehrlichiosis, is a tick-borne rickettsial pathogen that is infective to a wide range of mammals, including dogs and people. Amblyomma americanum, the lone star tick, is considered the primary vector of E. chaffeensis, but this pathogen has been detected in other tick species, including the brown dog tick, Rhipicephalus sanguineus. We hypothesized that the Arkansas strain of E. chaffeensis is infective to R. sanguineus, and used a novel PCR assay to test for acquisition of this pathogen by R. sanguineus and A. americanum ticks that were simultaneously fed on experimentally infected dogs. Although E. chaffeensis was not frequently detected in peripheral blood of these dogs, the pathogen was detected in both tick species and in canine lung, kidney, lymph node, bone marrow and frontal lobe samples. One dog (AFL) was maintained for several years, and ticks again acquired E. chaffeensis from this dog 566 days after intradermal inoculation with E. chaffeensis, but the pathogen was not detected in ticks fed on the same dog at 764 or 1086 days after the intradermal inoculation., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Amblyomma americanum, the lone star tick, is the most common and most aggressive human biting tick in the Southeastern United States. It is known to transmit the agents of human ehrlichioses, Ehrlichia chaffeensis and Ehrlichia ewingii. In addition, it carries agents of unspecified pathogenicity to humans, including Rickettsia amblyommii, Borrelia lonestari, and the newly emerging Panola Mountain Ehrlichia (PME). Surveillance of these ticks for recognized or emerging pathogens is necessary for assessing the risk of human infection. From 2005 to 2009, we surveyed A. americanum ticks from four locations in the state of Georgia. Ticks (1,183 adults, 2,954 nymphs, and 99 larval batches) were tested using a multiplex real-time polymerase chain reaction (PCR) assay designed to detect and discriminate DNA from Rickettsia spp., E. chaffeensis, and E. ewingii. This assay was capable of detecting as few as 10 gene copies of the aforementioned agents. Ticks were also tested for PME and B. lonestari by nested PCR. The prevalence of infection ranged from 0 to 2.5% for E. chaffeensis, 0 to 3.9% for E. ewingii, 0 to 2.2% for PME, 17 to 83.1% for R. amblyommii, and 0 to 3.1% for B. lonestari. There were 46 (4.1%) individual adults positive for two agents, and two females that were each positive for three agents. Two larval batches were positive for both B. lonestari and R. amblyommii, indicating the potential for transovarial transmission of both agents from a single female. Although infrequent in occurrence, the dynamics of coinfections in individual ticks should be explored further, given the potential implications for differential diagnosis and severity of human illness.

Background: Donor-derived infections from organ transplantation are rare occurrences with preoperative screening practices. Ehrlichia chaffeensis, a tick-borne illness, transmitted through solid organ transplantation has not been reported previously to our knowledge. We present cases of 2 renal allograft recipients who developed severe E. chaffeensis infection after receipt of organs from a common deceased donor., Methods: The 2 renal transplant patients who developed E. chaffeensis infection are reported in case study format with review of the literature., Results: Approximately 3 weeks after renal transplantation, both patients developed an acute febrile illness and rapid clinical decline. Recipient A underwent an extensive infectious workup that revealed positive E. chaffeensis DNA from polymerase chain reaction on peripheral blood. Recipient B's clinical team obtained acute and convalescent antibody titers for E. chaffeensis, which demonstrated acute infection. Recipients A and B were treated with doxycycline and tigecycline, respectively, with clinical cure., Conclusions: These cases demonstrate that tick-borne pathogens, such as E. chaffeensis, can be transmitted through renal transplantation. E. chaffeensis can be associated with excessive morbidity and mortality, commonly owing to delay in diagnosis and poor response to non-tetracycline antibiotics. In populations with endemic tick-borne illness, donors should be questioned about tick exposure, and appropriate antibiotics can be administered if indicated., (© 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Human monocytotropic ehrlichios is a tick borne illness caused by Ehrlichia chaffeensis. Ehrlichiosis presenting with septic shock and severe azotemia is rare, and may be seen in immunocompromised individuals. We present a case of ehrlichia induced toxic shock like syndrome in a patient with rheumatoid arthritis on disease modifying agents. He also had oliguric renal failure requiring dialysis on presentation and later found to have Hemophagocytic Lymphohistiocytosis secondary to severe ehrlichia sepsis.

In 2006, an unusual nosocomial outbreak of anaplasmosis occurred in Anhui Province, China. To follow these emerging tickborne-rickettsioses, a larger survey of Ehrlichia chaffeensis and Anaplasma phagocytophilum seroprevalence among farm worker populations, and the divergence of the partial 16S rRNA gene sequences of A. phagocytophilum among domestic animals, were conducted in Yanqing, Miyun, and Tongzhou Counties in Beijing from March to April, 2009. Blood samples from 562 farmers, 90 goats, 73 cattle, and 2 dogs were collected. IgG antibodies against E. chaffeensis and A. phagocytophilum were assayed by micro-indirect immunofluorescence assay (IFA). Partial fragments of 16S rRNA genes of A. phagocytophilum were amplified from blood DNA from domestic animals and their sequences analyzed. The total E. chaffeensis and A. phagocytophilum seroprevalence among the farm worker population was 16.4% and 14.1%, respectively. For domestic animals, the seropositive rates of A. phagocytophilum for goats, cattle, and dogs, were 2.3%, 0%, and 0%, respectively. The PCR-positive rates for A. phagocytophilum in goats and cattle were 48.9% and 23.9%, respectively. Three dominant genetic groups of Chinese A. phagocytophilum isolates were determined for goats and cattle, and these isolate varieties were broadly identified in China, Japan, and Korea. The prevalence of E. chaffeensis and A. phagocytophilum among farmers and domestic animals in Beijing rural areas was also demonstrated. The diagnoses and differential diagnoses of these emerging infectious diseases should be emphasized in clinics, and further ecological investigation of E. chaffeensis and A. phagocytophilum vectors and hosts is needed.

Bilateral anterior thigh pain may indicate bacteremia (Louria's Sign). We present a case of Ehrlichiosis due to Ehrlichia chaffeensis whose predominant presenting symptom was localized bilateral anterior thigh pain., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

In order to investigate new hosts for Anaplasmataceae agents in Brazil, we collected blood samples from 21 wild birds. Using molecular techniques, we detected the presence of Anaplasma phagocytophilum, Ehrlichia chaffeensis, and an Ehrlichia species closely related to Ehrlichia canis in carnivorous avian blood samples. In addition, an Ehrlichia species closely related to an Ehrlichia species found in wild felines in Brazil was also detected in a goose blood sample. Wild birds may play a role as carriers of Anaplasmataceae agents in Brazil.

Anaplasmataceae organisms comprise a group of obligate intracellular gram-negative, tick-borne bacteria that can infect both animals and humans. In the present work we investigate the presence of Ehrlichia, Anaplasma, and Neorickettsia species in blood samples from Brazilian marsh deer (Blastocerus dichotomus), using both molecular and serologic techniques. Blood was collected from 143 deer captured along floodplains of the Paraná River, near the Porto Primavera hydroelectric power plant. Before and after flooding, marsh deer were captured for a wide range research program under the financial support of São Paulo State Energy Company (CESP), between 1998 and 2001. Samples were divided into four groups according to time and location of capture and named MS01 (n=99), MS02 (n=18) (Mato Grosso do Sul, before and after flooding, respectively), PX (n=9; Peixe River, after flooding), and AGUA (n=17; Aguapeí River, after flooding). The seroprevalences for Ehrlichia chaffeensis and Anaplasma phagocytophilum were 76.76% and 20.2% in MS01, 88.88% and 5.55% in MS02, 88.88% and 22.22% in PX, and 94.12% and 5.88% in AGUA, respectively. Sixty-one animals (42.65% of the total population) were PCR-positive for E. chaffeensis PCR (100.0% identity based on 16S rRNA, dsb, and groESL genes). Seventy deer (48.95% of the total population) were PCR-positive for Anaplasma spp. (99.0% of identity with A. platys, and in the same clade as A. phagocytophilum, A. bovis, and A. platys based on 16S rRNA phylogenetic analysis). Our results demonstrate that Brazilian marsh deer are exposed to E. chaffeensis and Anaplasma spp. and may act as reservoirs for these rickettsial agents, playing a role in disease transmission to humans and other animals., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Objective: To investigate the status of Ehrlichia (E.) chaffeensis and Anaplasma (A.) phagocytophilum infection among farming populations and domestic animals in the rural area of Beijing, China., Methods: Blood samples from 562 farmers and 163 blood samples including 90 goats, 71 ox and 2 dogs, were collected. Specificity of IgG antibodies against E. chaffeensis and A. phagocytophilum were tested by micro-indirect immunofluorescent assay (mIFA). 16S rRNA genes of A. phagocytophilum were amplified from the domestic animal blood samples and products were sequenced and analyzed by nested PCR., Results: The positive rates of E. chaffeensis and A. phagocytophilum antibody were 16.5% and 14.0% respectively for farmers. The total positive rates of A. phagocytophilum were 2.3% and 0 for both goats and oxen respectively. No antibody was found for the 2 tested dogs. The PCR positive rates were 48.9% and 23.9% for goats and oxen respectively. Three dominant varieties of A. phagocytophilum were demonstrated in goats and oxen., Conclusion: The prevalence rates of E. chaffeensis and A. phagocytophilum were identified in the rural areas of Beijing.

Ehrlichial myocarditis is an unusual finding in nonimmunosuppressed patients. A case of fatal ehrlichiosis with rapidly progressive myocarditis and multiorgan failure from Ehrlichia chaffeensis in a previously healthy adolescent is described.

Human ehrlichiosis is the term for a collection of tick-borne diseases caused primarily by obligate intracellular bacteria of the Ehrlichia species. Ehrlichiosis is characterized by a mild to severe illness, with approximately 3-5% of cases proving fatal despite receiving appropriate care. This report presents the case of a 60 year-old woman who was found collapsed and unresponsive in her home after an indeterminate time; possibly for up to 48 h. Despite rigorous resuscitative care and antibiotic treatment, the patient lapsed into multi-organ failure and died. Subsequent analysis by microscopic examination, PCR and immunohistochemistry revealed the patient died from an infection of Ehrlichia chaffeensis. Clinicians and pathologists must be aware of this emergent disease in order to make a timely and appropriate diagnosis. Discussion of the patient's clinical, laboratory and autopsy findings as well as treatment of Ehrlichia chaffeensis infections is presented.

Ehrlichia chaffeensis causes human monocytic ehrlichiosis, and Anaplasma phagocytophilum causes human granulocytic anaplasmosis. These related tick-borne rickettsial organisms can cause severe and fatal illness. During 2000-2007, the reported incidence rate of E. chaffeensis increased from 0.80 to 3.0 cases/million persons/year. The case-fatality rate was 1.9%, and the hospitalization rate was 49%. During 2000-2007, the reported incidence of A. phagocytophilum increased from 1.4 to 3.0 cases/million persons/year. The case-fatality rate was 0.6%, and the hospitalization rate was 36%. Rates among female patients were lower than among male patients for ehrlichiosis (rate ratio = 0.68) and anaplasmosis (rate ratio = 0.70). Most (80%) ehrlichiosis and anaplasmosis cases met only a probable case definition, although, use of a polymerase chain reaction to confirm infections increased during 2000-2007. Heightened reporting of these diseases will likely continue with improving recognition, changing surveillance practices, and appropriate application of diagnostic assays.

Infection by Anaplasma and Ehrlichia in feral raccoons (Procyon lotor) in Hokkaido, Japan, was examined by molecular methods. A polymerase chain reaction (PCR) screen for Anaplasmataceae, based on 16S rRNA, showed that 38 (5.4%) of 699 raccoons examined were positive. These 38 positive samples were examined for Anaplasma phagocytophilum, Anaplasma bovis, Ehrlichia chaffeensis, and Ehrlichia canis infection by species-specific nested PCR. Nested PCR results indicated that 36 of the 38 samples were positive for A. bovis. All 38 samples were PCR negative for A. phagocytophilum, E. chaffeensis, and E. canis. This is the first report of the detection of A. bovis in the peripheral blood of raccoons. A total of 124 raccoons were infested with ticks, including Ixodes ovatus, Ixodes persulcatus, and Haemaphysalis spp. The rate of A. bovis infection in raccoons infested with Haemaphysalis spp. (46.7%, 7/15) was significantly higher than that in raccoons without Haemaphysalis spp. infestation (3.7%, 4/109, p < 0.001). No significant differences were observed in A. bovis infection rates between raccoons infested with I. ovatus or I. persulcatus and those not so infested. A total of four ticks (two males and two nymphs) and one larval pools from four raccoons showed positive for A. bovis-specific nested PCR. This results support the correlation between the A. bovis infection of raccoons and Haemaphysalis infestation. In conclusion, raccoons could be possible reservoir animals for A. bovis, and A. bovis infection in raccoons may be related to infestation with Haemaphysalis spp.

The salivary gland (SG) of tick plays an important role as a route in the dissemination of tick-borne pathogens to their hosts. We evaluated the presence of these pathogens in the SGs of Haemaphysalis longicornis ticks, and these ticks were collected from grazing cattle in Jeju Island, Korea. Of total 463 one-side SGs, 56 (12.1%) SGs were positive for Ehrlichia chaffeensis and 11 (2.4%) were positive for Anaplasma bovis. In addition, two (0.4%) SGs were co-infected with both E. chaffeensis and A. bovis. In conclusion, we specifically describe the presence of E. chaffeensis and A. bovis in the SGs of H. longicornis ticks in Korea.

Rhipicephalus sanguineus ticks (n = 63) collected from five dogs (two adults and three puppies) housed in a kennel were screened for Ehrlichial agents (Ehrlichia canis, E. chaffeensis, and E. ewingii) using a species-specific multicolor real-time TaqMan PCR amplification of the disulphide bond formation protein (dsb) gene. Ehrlichia chaffeensis DNA was detected in 33 (56%) ticks, E. canis DNA was detected in four (6%) ticks, and one tick was coinfected. The E. chaffeensis and E. canis nucleotide sequences of the amplified dsb gene (374 bp) obtained from the Cameroonian R. sanguineus ticks were identical to the North American genotypes.

To determine whether Ehrlichia chaffeensis exists in Japan, we used PCR to examine blood from sika deer in Nara, Japan. Of 117 deer, 36 (31%) were infected with E. chaffeensis. The E. chaffeensis 16S rRNA base and GroEL amino acid sequences from Japan were most closely related to those of E. chaffeensis Arkansas.

Rates of infection of Amblyomma americanum (L.) by Ehrlichia chaffeensis were compared in 100 ticks collected from sites in each of four states: Indiana, North Carolina, Kentucky, and Mississippi. The overall infection rates were similar among sites, ranging from 1 to 4%. Because pathogenic differences may exist between E. chaffeensis strains, nested polymerase chain reaction (PCR) amplification of the variable-length PCR target (VLPT), and sequencing of the amplicons were performed to differentiate between strains. The most common infecting strains at all sites exhibited a repeat profile of 1,2,3,4 (corresponding to the Arkansas/Jax/Osceola and Liberty strains). To determine whether the minimum infection rates (MIRs) or the most common infecting strain were changing over time in southern Indiana sites, 2765 ticks from six counties in 2000 and 837 ticks from seven counties in 2004 also were examined in pools of five ticks per pool. The MIRs for 2000 and 2004 were 3.5 and 4.2% respectively, suggesting that the overall MIRs remained low. At two sites, in Pike and Harrison counties, however, infection rates more than doubled from 2000 to 2004 (7 to 16% and 0.3 to 2.7% respectively). Across all sites, the most common infecting strains (Arkansas/Jax/Osceola and Liberty) did not significantly change (68% in 2000; 79% in 2004).

Ticks were collected from 38 black bears (Ursus americanus floridanus) from northwestern Florida (n = 18) from 2003 to 2005 and southern Georgia (n = 20) in 2006. Five species (Amblyomma americanum, A. maculatum, Dermacentor variabilis, Ixodes scapularis, and I. affinis) were collected from Florida bears, and 4 species (A. americanum, A. maculatum, D. variabilis, I. scapularis) were collected from bears in Georgia. Ixodes scapularis was the most frequently collected tick, followed by D. variabilis, A. americanum, A. maculatum, and I. affinis. The collection of I. affinis from a Florida bear represents a new host record. A subset of ticks was screened for pathogens and putative symbionts by polymerase chain reaction (PCR). The zoonotic tick-borne pathogens Ehrlichia chaffeensis and Rickettsia parkeri were detected in 1 of 23 (4.3%) A. americanum and 1 of 12 (8.3%) A. maculatum, respectively. The putative zoonotic pathogen "Rickettsia amblyommii" was detected in 4 (17.4%) A. americanum and 1 (8.3%) A. maculatum. Other putative symbiotic rickettsiae detected included R. bellii and R. montanensis in D. variabilis, a Rickettsia cooleyi-like sp. and Rickettsia sp. Is-1 in I. scapularis, and Rickettsia TR39-like sp. in I. scapularis and A. americanum. All ticks were PCR-negative for Anaplasma phagocytophilum, Panola Mountain Ehrlichia sp., E. ewingii, Francisella tularensis, and Borrelia spp.