Anaplasma phagocytophilum infection associated with strong inflammatory response in 3 cats.

Anaplasmosis is a vector-borne disease caused by Anaplasma (A.) spp. which currently is still rarely diagnosed in cats. This article describes 3 independent cases of anaplasmosis in cats from different regions of Germany presented to veterinarians in 2021. All cats showed unspecific clinical signs, such as fever, reduced general condition, and decreased appetite. One cat additionally had generalized limb pain, another showed reluctance to move as well as vomiting. On complete blood cell count, only 1 of 3 cats showed mild thrombocytopenia. A. phagocytophilum was detected in blood samples of all 3 cats by polymerase chain reaction. Additionally, in 2 cats (in which blood smears were evaluated) morulae could be detected within neutrophilic granulocytes. Initially, all 3 cats had highly elevated serum amyloid A (SAA) concentrations. Treatment with doxycycline caused a rapid improvement of clinical signs, followed by a decrease of SAA concentrations to normal levels as well as negative PCR results after a treatment duration of at least 28 days. In cats with fever, otherwise unspecific clinical signs with only mild or no hematological changes, elevated SAA concentrations, and previous exposure to ticks, attending veterinarians should consider anaplasmosis as differential diagnosis.

Homeopatia em trombocitopenia canina: relato de caso / Homeopathy in canine thrombocytopenia: case report

Hemoparasitoses constituem-se de enfermidades cosmopolitas que são causadas por parasitos intracelulares obrigatórios de células sanguínea. Os mais frequentemente encontrados nos cães são a babesiose, erliquiose e anaplasmose. O tratamento consiste no uso de antibiótico do grupo das tetraciclinas, sendo a doxiciclina o medicamento mais indicado. O objetivo deste relato de caso é descrever o tratamento homeopático em um cão da raça shih-tzu, senil (8 anos de idade), cardiopata com trombocitopenia discreta secundário a hemoparasitose ­ ehrlichiose. O medicamento homeopático repertorizado foi Phosphorus 30 cH 3 glóbulos 2x ao dia por 3 dias. Foi administrado também a Calcarea Carbonica 6 cH 3 glóbulos 2x ao dia por 7 dias. Tal sucesso terapêutico foi atingido em 3 dias de tratamento, com melhora laboratorial da trombocitopenia e do quadro de dispnéia. Este estudo contribui com pesquisas existentes a caráter de novos tratamentos para a ehrlichiose canina.

Hemoparasitoses are cosmopolitan diseases that are caused by obligate intracellular parasites of blood cells. The most frequently found in dogs are babesiosis, ehrlichiosis and anaplasmosis. Treatment consists of the use of antibiotics from the tetracycline group, with doxycycline being the most indicated medication. The objective of this case report is to describe the homeopathic treatment in a dog of the shih-tzu breed, senile (8 years old), heart disease with mild thrombocytopenia secondary to hemoparasitosis - ehrlichiosis. The repertorized homeopathic medicine was Phosphorus 30 cH 3 globules 2x a day for 3 days. Calcarea Carbonica 6 cH 3 globules was also administered twice a day for 7 days. Such therapeutic success was achieved in 3 days of treatment, with laboratory improvement of thrombocytopenia and dyspnea. This study contributes to existing research on new treatments for canine ehrlichiosis.

Impact of tick-borne Anaplasma phagocytophilum infections in calves of moose (Alces alces) in southern Norway.

The Gram-negative, obligate intracellular tick-transmitted pathogen Anaplasma phagocytophilum can cause acute febrile diseases in humans and domestic animals. The expansion of the tick Ixodes ricinus (Linnaeus, 1758) in northern Europe due to climate change is of serious concern for animal and human health. The aim of the present study was to investigate the impact of A. phagocytophilum infection in moose Alces alces (Linnaeus) calves by evaluating the carcass weights of infected and non-infected animals and examining animal tissues samples for co-infections with either species of Babesia Starcovici, 1893 or bacteria of the genus Bartonella. The carcasses of 68 free-ranging moose calves were weighed by hunters during the hunting seasons from 2014 to 2017 in two regions in southern Norway and spleen samples were collected. Anaplasma phagocytophilum was detected in moose sampled from locations infected with ticks with a prevalence of 82% (n = 46). The carcass weights of A. phagocytophilum-infected calves (n = 46) and non-infected (n = 22) calves were compared. Although the average weight of infected calves (45.6 kg) was lower than that of non-infected calves (46.5 kg), the difference was not statistically significant. Three different variants of the bacterium 16S rRNA gene were identified. The average weight of animals infected with variant I was 49.9 kg, whereas that of animals infected with variant III was 42.0 kg, but the difference was not statistically significant (p = 0.077). Co-infections of A. phagocytophilum with Bartonella spp. or with Babesia spp. were found in 20 and two calves, respectively. A triple infection was found in two calves. Sequence analysis of the 18S rRNA gene of Babesia-positive samples revealed the presence of Babesia cf. odocoilei (Emerson et Wright, 1970). Strains of Bartonella closely related to Bartonella bovis (Bermond, Boulouis, Heller, Laere, Monteil, Chomel, Sander, Dehio et Piemont, 2002) were identified based on phylogenetic analysis of the gltA and rpoB genes. The loss of body mass in moose calves in the tick-infected site was probably influenced by multiple factors.

Dal-induced red blood cell incompatibilities in a Doberman Pinscher with von Willebrand factor deficiency and ehrlichiosis.

OBJECTIVE: To describe a complex case involving the management of a dog with von Willebrand disease (vWD), active ehrlichiosis infection, nonregenerative anemia, and blood type incompatibility related to the Dal antigen. CASE SUMMARY: A 13-week-oldintact male Doberman Pinscher weighing 7.2 kg was presented to the emergency service for a previous hemorrhaging event and progressive nonregenerative anemia. The dog had received a fresh whole blood transfusion 8 days prior to presentation due to severe anemia. Upon presentation, the puppy was tachycardic, and his mucous membranes were pale. A CBC revealed a nonregenerative anemia with a PCV of 0.11 L/L (11%). von Willebrand factor deficiency was suspected and later confirmed. The dog's blood type was dog erythrocyte antigen (DEA) 1 positive, but cross-matching to 4 RBC units, both DEA 1 positive and negative, failed to yield any compatible units. Antibody against a possible Dal RBC antigen was suspected, and 11 blood donors (Dalmatians and Dobermans) were cross-matched to find 2 compatible donors. After an uneventful fresh whole blood transfusion, a bone marrow biopsy revealed a hypocellular bone marrow and erythroid hypoplasia. A SNAP4DxPlus test and subsequent polymerase chain reaction (PCR) testing were positive for Ehrlichia ewingii and E. canis. Treatment with doxycycline was started, and the PCV was 0.17 L/L (17%) at discharge. At the 1-week follow-up, the PCV was 0.24 L/L (24%), and the puppy was doing well. NEW OR UNIQUE INFORMATION PROVIDED: This is a unique case of a dog presenting with several challenging disorders, including vWD resulting in hemorrhage, ehrlichiosis potentially contributing to a nonregenerative anemia, and a blood type incompatibility due to the Dal antigen. Doberman Pinschers have a high prevalence of vWD- and Dal-negative phenotype, which emphasizes the value of cross-matching and the recognition of antigen prevalence in specific breeds.

Hemophagocytic Lymphohistiocytosis Secondary to Ehrlichia Chaffeensis in Adults: A Case Series From Oklahoma.

Hemophagocytic lymphohistiocytosis (HLH) is a syndrome of pathologic immune activation that occurs as either a familial disorder or as a sporadic condition in association with a variety of triggers. Infections are the most common cause of HLH in adults and should be searched for as early treatment usually results in a favorable outcome. Human monocytotropic ehrlichiosis (HME) is a very rare cause of HLH. Failure to consider ehrlichiosis can result in misdiagnosis and an increased length of hospitalization and healthcare cost as described in our report. Treatment for secondary HLH is aimed at reducing hypercytokinemia and eradicating inflammatory and infected cells. It is important to promptly initiate doxycycline when tick-borne diseases are being entertained as a possible trigger, as the antibiotic is effective, safe and inexpensive.

A 58-Year-Old Man With Acute Encephalopathy, Fever, and Multi-Organ Dysfunction.

CASE PRESENTATION: A 58-year-old man with a medical history of type 2 diabetes mellitus and COPD presented with fever, chills, nausea, vomiting, left upper quadrant abdominal pain, and altered mental status for the past week. His mental status rapidly deteriorated and work of breathing increased, which required intubation and mechanical ventilation. The patient's wife reported recent exposure to tick bites after finding several ticks while changing the sheets in their bedroom.

Gastrointestinal and hepatic symptoms of tickborne diseases.

While investigating patients with gastrointestinal (GI) and/or hepatic symptoms, tickborne diseases are only rarely considered to be the cause. However, the Czech Republic is an endemic region for several of tickborne diseases and, therefore, they should be a part of differential diagnosis of GI symptoms of unknown origin. This article describes GI and hepatic symptoms of several tickborne diseases - Lyme disease, ehrlichiosis, Rocky mountain spotted fever, tularemia, Colorado tick fever, tickborne relapsing fever, Q fever and babesiosis. GI and hepatic symptoms are quite common in Lyme disease patients. The prognosis is generally favourable with antibiotics treatment, however, serious courses have been described. Lyme disease should be a part of differential diagnosis of liver tests elevation and GI symptoms in patients from endemic regions regardless erythema migrans presence. Ehrlichiosis should be a part of differential diagnosis of acute febrile illness with GI symptoms especially in the presence of leukopenia/thrombocytopenia and/or liver tests elevation. Tularemia should be considered as a rare etiology of cholestatic hepatopathy and a history of a tick bite. In general, the importance of careful patient interviewing, including the history of a tick bite, can be highlighted also as a part of investigation of patients with seemingly unrelated GI and/or hepatic symptoms.

Case Report: Anaplasmosis in Canada: Locally Acquired Anaplasma phagocytophilum Infection in Alberta.

Human granulocytic anaplasmosis is an obligate intra-granulocytic parasite that is transmitted by Ixodes scapularis and Ixodes pacificus in North America. We report on the second laboratory-confirmed case of Anaplasma phagocytophilum acquired within the province of Alberta, Canada. A 67-year-old woman from the Edmonton health zone developed nonspecific systemic symptoms including fatigue, night sweats, myalgia, headaches, and fever 6 days after noticing a tick on her left upper arm in May of 2017 (day 0). On day 13, she was found to have thrombocytopenia. Her symptoms progressed until day 16 when she was treated empirically with doxycycline, at which time she slowly improved over the subsequent 2 months. The tick was later identified as a partially engorged female blacklegged tick, I. scapularis, and it was positive for A. phagocytophilum DNA by PCR. Anaplasma serology performed retrospectively on blood samples collected on days 13, 31, and 52 showed a greater than 4-fold increase in A. phagocytophilum (IgG titers from less than 1:64 on day 13 to 1:2048 on days 31 and 52), consistent with an acute infection. Although populations of blacklegged ticks are not yet established in Alberta, suspicion should remain for tick-borne diseases because infected ticks are introduced into the province by migrating birds. This case report highlights the need to remind physicians and other public health professionals that rare, non-endemic tick-borne diseases can occasionally occur in low-risk jurisdictions.

The co-infection with Ehrlichia minasensis, Anaplasma marginale and Anaplasma platys is not associated with anemia in beef cattle in the Brazilian Pantanal.

The Anaplasmataceae family is composed of obligatory intracellular Gram-negative bacteria transmitted by arthropod vectors. In Brazil, with the exception of Anaplasma marginale, little is known about the occurrence of other Anaplasma and Ehrlichia species infecting cattle. The present study aimed at investigating the occurrence of Anaplasma spp. and Ehrlichia spp. in beef cattle (Bos indicus) sampled in the Brazilian Pantanal, an area prone to periodic flooding and endemic for bovine trypanosomiasis. Blood samples from 400 cattle were collected and screened by PCR assays based on rrs and dsb genes from Anaplasma spp. and Ehrlichia spp., respectively. Positive samples for Anaplasma spp. were subjected to qPCR assays based on the msp-2 gene and nPCR based on the groEL gene. As a result, 4.75% (19/400) and 48.12% (167/347) were positive for Anaplasma platys and Ehrlichia minasensis, respectively. Besides, positivity of 56.75% (227/400) for A. marginale and seropositivity of 90.75% (363/400) for Trypanosoma vivax were found. A high rate of co-infection was observed (67.25%), from which the co-infection by A. marginale and E. minasensis was more frequently found in calves than cows. Interestingly, none of the animals presenting co-infection showed anemia or other clinical signs. The present study showed, for the first time, the occurrence of A. platys and E. minasensis in beef cattle in the southern Pantanal, as well as a high rate of co-infection by A. marginale, E. minasensis and T. vivax in the sampled animals.

Incidence and treatment of hemophagocytic lymphohistiocytosis in hospitalized children with Ehrlichia infection.

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.

Association Between Exposure to Ehrlichia spp. and Risk of Developing Chronic Kidney Disease in Dogs.

Ehrlichiosis is a common vector-borne disease caused by Ehrlichia spp. This retrospective matched cohort study was performed to determine if dogs with Ehrlichia spp. antibodies had an increased incidence of chronic kidney disease (CKD). Exposure to Ehrlichia spp. was defined as having an Ehrlichia spp. antibody-positive result recorded at any point in their available patient history. The outcome of CKD was defined as concurrent increased symmetric dimethylarginine (>14 µg/dL) and creatinine (>1.5 mg/dL) for a minimum of 25 days with inappropriate urine specific gravity (<1.030). Patients were matched using propensity score matching to control for age, geography, and breed. A total of 22,440 patients and controls in E canis-endemic regions of the United States were used in this analysis. Contingency tables were used to compare dogs with and without exposure to Ehrlichia spp.-infected ticks and CKD outcome. The relative risk of CKD for patients exposed to ticks carrying Ehrlichia spp. was found to be 2.12 (95% confidence interval [1.35-3.15], p < 0.0006). This study identified that testing positive for Ehrlichia spp. antibodies in E canis-endemic regions is associated with higher incidence of CKD in dogs.

Evaluation of heart rate variability and behavior of electrocardiographic parameters in dogs affected by chronic Monocytic Ehrlichiosis.

Canine Monocytic Ehrlichiosis (CME) is a systemic disease prevalent in the entire world caused by the obligate intracellular bacteria Ehrlichia canis. The occurrence of myocarditis with a high prevalence of arrhythmias in dogs affected by this disease in the cytopenic phase has already been proven. This study aims to evaluate the concentrations of CK MB, cTnI and NT-proBNP in dogs affected by Ehrlichia canis in the chronic phase since the intense stimulation of the immune system can lead to myocarditis; to evaluate if the condition can lead to arrhythmic events and, if so, define their frequency and classification through conventional and ambulatory electrocardiogram tests (Holter method) for a period of 24 hours; to analyze heart rate variability in the time domain and whether the condition can lead to autonomic imbalance; and to determine the survival rate of affected dogs, identifying possible risk factors for mortality at this stage of the disease. For this purposes, we evaluated clinical, hematological and biochemical data, as well as the concentrations of cardiac biomarkers Creatine Kinase-MB (CK MB), Cardiac Troponin I (cTnI) and N-terminal pro-peptide natriuretic type B (NT-proBNP). We also analyzed conventional and ambulatory electrocardiography (24-hour Holter) and heart rate variability (HRV) in 20 dogs afflicted by cytopenic CME in the chronic phase of the disease (G1) and compared the results with a control group comprised of ten healthy dogs (G2). G1 was monitored during the treatment for 28 days, during which eight (8) of the 20 infected dogs died (40%). Anorexia, vomiting, fatigue, hypoalbuminemia, heart murmurs and increased concentrations of alanine aminotransferase (ALT) and alkaline phosphatase (ALP) were common clinical signs. The mean concentrations of cTnI and CKMB were significant (0.24 ng / mL ± 0.5, 229 ± 205 IU / mL) in comparison to the control group (0.042 ± 0.07 ng / mL, 126 ± 46.12 IU / mL). No significant differences were observed between NT-proBNP concentrations in G1 (135.46 ± 29.7) and G2 (138.28 ± 19.77). Nine of the twenty dogs (45%) presented a high frequency of arrhythmias during 24-hour recording, ranging from first and second-degree atrioventricular block, ventricular and supraventricular ectopic events and sinus tachycardia. No sinus pause was observed. One dog had 120 episodes of unsustained ventricular tachycardia and two episodes of sustained ventricular tachycardia. The short-term and long-term HRV data, represented by SDNN (ms), SDANN (ms) and pnn50 (%) were also significant lower (83 ± 65, 56.05 ± 37.3 and 14.56 ± 20, respectively) in comparison to the healthy animals (268 ± 74.6, 168.3 ± 39.14 and 55.87 ± 12.8, respectively). These results suggest that cytopenic CME is characterized by an arrhythmogenic component and intense stimulation of the sympathetic autonomic nervous system in the heart, reflecting an imbalance in the activity of the ANS.

Conventional and Holter Electrocardiographic Assessment of Dogs Infected Naturally With Acute Canine Monocytic Ehrlichiosis.

Canine Monocytic Ehrlichiosis (CME) is a disease of worldwide distribution caused by the bacteria Ehrlichia canis, appearing primarily in hot climates due to the massive prevalence of its vector, the tick Rhipicephalus sanguineus. Previous studies have shown that dogs afflicted by CME in the chronic phase can develop infectious myocarditis, arrhythmias, and alterations in heart rate variability (HRV), but there are few studies correlating cardiac diseases with the acute phase of CME. This study aims at assessing electric cardiac alterations and HRV in the time and frequency domains during the acute phase of CME. This study assessed 22 animals divided into 2 distinct groups: the control group, comprised by 10 healthy dogs, and the sick group, comprised of 12 dogs infected naturally with ehrlichiosis which presented clinical and hematological signs compatible with the acute phase of the disease. The animals underwent conventional and Holter electrocardiographic evaluations, systolic blood pressure measurement, complete blood count and biochemical assays (urea, creatinine, alanine aminotransferase (ALT), alkaline phosphatase (AP), and gamma glutamyl transferase (GGT)). The sick group presented higher activity in the sympathetic nervous system than in the parasympathetic nervous system, manifest as a significant increase in mean heart rate and a reduction in the HRV indexes for the time and frequency domains. The frequency-domain HRV indexes presented sympathetic prevalence during the sleep and vigilance states. Sinus tachycardia was the predominant heart rhythm in 58.33% of the animals. The mean systolic blood pressure diverged between the groups and no significant arrhythmias were observed during monitoring. The serum concentrations of urea, creatinine, AP, ALT, and GGT were within the established reference values for the species. We observed no indication that there was enough time during the acute phase for the disease to evolve in a way that resulted in arrhythmias, as is common in the chronic phase, but we observed that animals in the acute phase already present reduced HRV indexes.

An update on the treatment of canine monocytic ehrlichiosis (Ehrlichia canis).

Canine monocytic ehrlichiosis (CME), caused by Ehrlichia canis, a gram-negative, obligate intracellular bacterium, is a tick-borne disease of worldwide distribution. Experimentally, the course of E. canis infection can be sequentially divided into acute, subclinical and chronic phases, although distinction of these phases is challenging in the clinical setting. Spontaneous clinical recovery of acutely infected dogs is common; however, dogs at this stage require medical treatment in order to hasten their clinical recovery, and to prevent clinical exacerbation or death. An unpredictable proportion of subclinically infected dogs will eventually develop the chronic, severe form of ehrlichiosis, characterized by aplastic pancytopenia and high mortality. The aims of antimicrobial treatment in CME include the achievement of clinical remission, resolution of the clinicopathologic abnormalities, and eradication of the infection, although the latter is not always feasible or diagnostically confirmable. Treatment of dogs with aplastic pancytopenia should be undertaken with the clear understanding that medical management will require long-term care, will be expensive, and may eventually prove ineffective. This manuscript reviews the current state of knowledge regarding treatment of ehrlichiosis, caused by E. canis infection in dogs, provides expert opinion guidelines for the management of the CME-associated aplastic pancytopenia, and outlines methods for evaluation of treatment outcomes.

First report of human ehrlichiosis in Turkey.

Emiroglu M, Çelebi B. First report of human ehrlichiosis in Turkey. Turk J Pediatr 2019; 61: 267-270. Ehrlichiosis, a tick-borne infection, can cause severe and fatal disease. A 6-year-old boy was admitted with fever, chills, malaise, headache, anorexia, rhinorrhoea, and cough lasting two days. He had had contact with a dog 10 days prior, and a tick had been removed the day before. Fever, minimal conjunctival injection, oropharyngeal hyperemia and cracked, hyperemic lips were observed. Laboratory tests were normal except for lymphopenia and hyponatremia. Cytoplasmic morulae in the monocytes and granulocytes were seen on peripheral blood smear. Doxycycline was started immediately, and the fever subsided within 48 hours. Given the Ehrlichia was positive but Anaplasma negative by real-time PCR, he was diagnosed as ehrlichiosis, subspecies identification could not be performed. This is the first human ehrlichiosis case in Turkey.

The relationship between ehrlichiosis and the development of hematologic malignancies.

Viral and bacterial infections cause chronic inflammation and produce bacterial metabolites that may lead to carcinogenesis. Ehrlichiosis is an intracellular infection that primarily infects white blood cells. Given that infections can lead to cancer, and that Ehrlichia has tropism for white blood cells, it can be deduced that Ehrlichia may cause hematologic malignancies, such as acute leukemia. A prospective study was performed that tested the blood of ten patients with acute leukemia for prior exposure to Ehrlichia. The RT-PCR that was performed did not detect Ehrlichia DNA in any of the ten samples. Therefore, based on this small study, one cannot conclude that Ehrlichia can lead to hematologic malignancies.

Role of mustelids in the life-cycle of ixodid ticks and transmission cycles of four tick-borne pathogens.

BACKGROUND: Elucidating which wildlife species significantly contribute to the maintenance of Ixodes ricinus populations and the enzootic cycles of the pathogens they transmit is imperative in understanding the driving forces behind the emergence of tick-borne diseases. Here, we aimed to quantify the relative contribution of four mustelid species in the life-cycles of I. ricinus and Borrelia burgdorferi (sensu lato) in forested areas and to investigate their role in the transmission of other tick-borne pathogens. Road-killed badgers, pine martens, stone martens and polecats were collected in Belgium and the Netherlands. Their organs and feeding ticks were tested for the presence of tick-borne pathogens. RESULTS: Ixodes hexagonus and I. ricinus were found on half of the screened animals (n = 637). Pine martens had the highest I. ricinus burden, whereas polecats had the highest I. hexagonus burden. We detected DNA from B. burgdorferi (s.l.) and Anaplasma phagocytophilum in organs of all four mustelid species (n = 789), and Neoehrlichia mikurensis DNA was detected in all species, except badgers. DNA from B. miyamotoi was not detected in any of the investigated mustelids. From the 15 larvae of I. ricinus feeding on pine martens (n = 44), only one was positive for B. miyamotoi DNA, and all tested negative for B. burgdorferi (s.l.), N. mikurensis and A. phagocytophilum. The two feeding larvae from the investigated polecats (n = 364) and stone martens (n = 39) were negative for all four pathogens. The infection rate of N. mikurensis was higher in feeding nymphs collected from mustelids compared to questing nymphs, but not for B. burgdorferi (s.l.), B. miyamotoi or A. phagocytophilum. CONCLUSIONS: Although all stages of I. ricinus can be found on badgers, polecats, pine and stone martens, their relative contribution to the life-cycle of I. ricinus in forested areas is less than 1%. Consequently, the relative contribution of mustelids to the enzootic cycles of I. ricinus-borne pathogens is negligible, despite the presence of these pathogens in organs and feeding ticks. Interestingly, all four mustelid species carried all stages of I. hexagonus, potentially maintaining enzootic cycles of this tick species apart from the cycle involving hedgehogs as main host species.

Ehrlichiosis masquerading as thrombotic thrombocytopenic purpura.

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.