Human granulocytic ehrlichiosis in pancreas transplant recipients

Challenges of Diagnosing Severe Ehrlichiosis in Orthotopic Liver Transplant Recipients

In recent solid organ transplant recipients, acute febrile illness is usually a source of grave concern and a diagnostic dilemma, especially if no response is noted after initiation of broad antimicrobial therapy. Human Monocytic Ehrlichiosis (HME) is a tick-borne illness caused by Ehrlichia chaffeensis and is not considered an opportunistic infection in immunocompromised patients such as solid organ transplant patients. Ehrlichiosis in immunocompromised patients can be life-threatening, and a strong index of suspicion is needed, especially in patients who live in endemic areas, for proper treatment initiation with doxycycline. We report a case of a 40-year-old male who received an orthotopic liver transplant six months earlier secondary to primary sclerosing cholangitis, on chronic immunosuppressive medication, who presented with complaints of sudden onset fever associated with nausea, vomiting, and diarrhea. Initial extensive infectious workup was negative and no response to empiric antimicrobials. There was suspicion for ehrlichiosis prompting empiric doxycycline use. Subsequently, E. chaffeensis polymerase chain reaction (PCR) was positive, and the antibiotic regimen was de-escalated to only doxycycline with complete resolution of his symptoms and progressive improvement in previously abnormal biochemical indices.

Ehrlichiosis and Anaplasmosis among Transfusion and Transplant Recipients in the United States

Physicians should be aware that these infections are rare but can have severe outcomes.

Ehrlichiosis and anaplasmosis are emerging tickborne diseases that can also be transmitted through blood transfusions or organ transplants. Since 2000, ehrlichiosis and anaplasmosis cases in the United States have increased substantially, resulting in potential risk to transplant and transfusion recipients. We reviewed ehrlichiosis and anaplasmosis cases among blood transfusion and solid organ transplant recipients in the United States from peer-reviewed literature and Centers for Disease Control and Prevention investigations. We identified 132 cases during 1997–2020, 12 transfusion-associated cases and 120 cases in transplant recipients; 8 cases were donor-derived, and in 13 cases illness occurred <1 year after transplant. Disease in the remaining 99 cases occurred ≥1 year after transplant, suggesting donor-derived disease was unlikely. Severe illness or death were reported among 15 transfusion and transplant recipients. Clinicians should be alert for these possible infections among transfusion and transplant recipients to prevent severe complications or death by quickly treating them.

Emerging and neglected zoonoses in transplant population

Zoonoses represent a problem of rising importance in the transplant population. A close relationship and changes between human, animal and environmental health (“One Health” concept) significantly influence the transmission and distribution of zoonotic diseases. The aim of this manuscript is to perform a narrative review of the published literature on emerging and neglected zoonoses in the transplant population. Many reports on donor-derived or naturally acquired (re-)emerging arboviral infections such as dengue, chikungunya, West Nile, tick-borne encephalitis and Zika virus infection have demonstrated atypical or more complicated clinical course in immunocompromised hosts. Hepatitis E virus has emerged as a serious problem after solid organ transplantation (SOT), leading to diverse extrahepatic manifestations and chronic hepatitis with unfavorable outcomes. Some neglected pathogens such as lymphocytic choriomeningitis virus can cause severe infection with multi-organ failure and high mortality. In addition, ehrlichiosis may be more severe with higher case-fatality rates in SOT recipients. Some unusual or severe presentations of borreliosis, anaplasmosis and rickettsioses were also reported among transplant patients. Moreover, toxoplasmosis as infectious complication is a well-recognized zoonosis in this population. Although rabies transmission through SOT transplantation has rarely been reported, it has become a notable problem in some countries. Since the spreading trends of zoonoses are likely to continue, the awareness, recognition and treatment of zoonotic infections among transplant professionals should be imperative.

Anaplasma phagocytophilum presenting with orchitis in a renal transplant recipient

Human granulocytic anaplasmosis (HGA), caused by Anaplasma phagocytophilum, is an emerging tick-borne disease. It is spread by the black-legged deer tick Ixodes scapularis that serves as the vector for six human pathogens. HGA is still rarely reported in solid organ transplant recipients. In solid organ transplant recipients, orchitis has been reported secondary to chickenpox, tuberculosis and infections due to Listeria monocytogenes and Nocardia asteroides. Orchitis as a presenting feature of HGA infection has only been reported in animals. We present a unique case of a renal transplant recipient with HGA that presented as orchitis. We also compare the clinical presentation and laboratory findings of our patient with other cases of HGA in transplant recipients. To the best of our knowledge, our patient is one of the first cases of A phagocytophilum mono-infection causing a classical presentation of orchitis in a transplant patient.

Human ehrlichiosis at a tertiary-care academic medical center: Clinical associations and outcomes of transplant patients and patients with hemophagocytic lymphohistiocytosis

BACKGROUND

Ehrlichiosis is an acute febrile tick-borne disease which can rarely be a trigger for secondary hemophagocytic lymphohistiocytosis (HLH).

METHODS

We reviewed our experience with Ehrlichia infections at a tertiary-care academic medical center.

RESULTS

Over 10 years, 157 cases of ehrlichiosis were identified. Ten patients (6.4%) had infection with E. ewingii, 7(4.5%) of whom were transplant patients as compared to 3(1.9%) non-transplant patients (p = .035). Transplant patients were more likely to have leukopenia and elevated creatinine compared to immunocompetent patients; length of hospital stay and early mortality were not different between the two groups. Ten patients met the HLH-2004 diagnosis criteria, which could be an underestimation of HLH occurrence as most patients were not completely evaluated for these criteria. We calculated the H-Score to find the probability of HLH; 25 patients scored high making the occurrence rate of HLH at least 16%. Ehrlichia-induced HLH patients (N = 25) had more anemia, thrombocytopenia, elevated creatinine and AST. Moreover, they had a significantly longer hospital stay (median 9 days) compared to patients without HLH (median 4 days) (p = .006).

CONCLUSIONS

Ehrlichia-induced HLH is a potential serious complication with relatively high occurrence rate; patients manifest severe disease with end-organ damage requiring longer hospital stay.

Murine typhus in a liver transplant recipient: report of a first case

Zoonoses, especially rickettsial diseases, are rarely reported in solid organ transplant recipients. We report here a case of murine typhus in a 69-year-old liver transplant recipient, who presented with acute febrile illness 5 years post transplantation. Although receiving treatment with broad-spectrum antibiotics, he was still febrile and developed progressive dyspnea. Laboratory results showed elevated transaminases and his chest radiograph revealed bilateral interstitial infiltration. The diagnosis of murine typhus was made by a 4-fold rise in specific Rickettsia typhi antibody, using indirect immunofluorescent assay. He dramatically improved after treatment with doxycycline for 7 days. To our knowledge, this is the first case report of murine typhus in a liver transplant recipient.

Chronic coinfections in patients diagnosed with chronic lyme disease: a systematic review

PURPOSE

Often, the controversial diagnosis of chronic Lyme disease is given to patients with prolonged, medically unexplained physical symptoms. Many such patients also are treated for chronic coinfections with Babesia, Anaplasma, or Bartonella in the absence of typical presentations, objective clinical findings, or laboratory confirmation of active infection. We have undertaken a systematic review of the literature to evaluate several aspects of this practice.

METHODS

Five systematic literature searches were performed using Boolean operators and the PubMed search engine.

RESULTS

The literature searches did not demonstrate convincing evidence of: 1) chronic anaplasmosis infection; 2) treatment-responsive symptomatic chronic babesiosis in immunocompetent persons in the absence of fever, laboratory abnormalities, and detectable parasitemia; 3) either geographically widespread or treatment-responsive symptomatic chronic infection with Babesia duncani in the absence of fever, laboratory abnormalities, and detectable parasitemia; 4) tick-borne transmission of Bartonella species; or 5) simultaneous Lyme disease and Bartonella infection.

CONCLUSIONS

The medical literature does not support the diagnosis of chronic, atypical tick-borne coinfections in patients with chronic, nonspecific illnesses.

Severe life-threatening Ehrlichia chaffeensis infections transmitted through solid organ transplantation

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.

Increasing incidence of Ehrlichia chaffeensis and Anaplasma phagocytophilum in the United States, 2000-2007

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.

The natural history of Anaplasma phagocytophilum

Anaplasma phagocytophilum is the recently designated name replacing three species of granulocytic bacteria, Ehrlichia phagocytophila, Ehrlichia equi and the agent of human granulocytic ehrlichiosis, after the recent reorganization of the families Rickettsiaceae and Anaplasmataceae in the order Rickettsiales. Tick-borne fever (TBF), which is caused by the prototype of A. phagocytophilum, was first described in 1932 in Scotland. A similar disease caused by a related granulocytic agent was first described in horses in the USA in 1969; this was followed by the description of two distinct granulocytic agents causing similar diseases in dogs in the USA in 1971 and 1982. Until the discovery of human granulocytic anaplasmosis (HGA) in the USA in 1994, these organisms were thought to be distinct species of bacteria infecting specific domestic animals and free-living reservoirs. It is now widely accepted that the agents affecting different animal hosts are variants of the same Gram-negative obligatory intracellular bacterium, which is transmitted by hard ticks belonging to the Ixodes persulcatus complex. One of its fascinating features is that it infects and actively grows in neutrophils by employing an array of mechanisms to subvert their bactericidal activity. It is also able to survive within an apparently immune host by employing a complex mechanism of antigenic variation. Ruminants with TBF and humans with HGA develop severe febrile reaction, bacteraemia and leukopenia due to neutropenia, lymphocytopenia and thrombocytopenia within a week of exposure to a tick bite. Because of the severe haematological disorders lasting for several days and other adverse effects on the host's immune functions, infected animals and humans are more susceptible to other infections.

Clinical outcomes of solid organ transplant recipients with ehrlichiosis

Because of our experience with severe Ehrlichia infections in lung transplant recipients, we reviewed all cases of ehrlichiosis in solid organ transplant recipients at Barnes-Jewish Hospital in St. Louis, Missouri. Between 1996 and 2007, 25 cases of ehrlichiosis were identified. We retrospectively collected demographic, clinical, laboratory, and outcomes data, and we compared the 5 cases in lung transplant recipients with 20 cases in other solid organ transplant recipients (heart, 2; kidney, 13; liver, 5). The presenting symptoms in the majority of both groups consisted of fever and headache. Clinical outcomes were worse in the lung transplant group and included a greater need for intensive care unit treatment (80% vs. 20%, P=0.02), longer length of hospital stay (21 vs. 5 days, P=0.02), and propensity to develop acute lung injury or acute respiratory distress syndrome (60% vs. 10%, P=0.04). No mortalities occurred in either group of patients. In an endemic area, ehrlichiosis is not unusual in solid organ transplant recipients, and lung transplant recipients tend to have a more severe illness.

Lyme disease followed by human granulocytic anaplasmosis in a kidney transplant recipient

We report the case of a kidney transplant recipient who developed Lyme disease, followed by human granulocytic anaplasmosis (HGA) 3 years later. A review of all previously published cases of Lyme disease (3 cases), HGA (5 cases), and human monocytic ehrlichiosis (HME) (5 cases) in transplant recipients is presented. Manifestations of the cases reviewed were similar to those of non-transplant patients. There appeared to be no obvious correlation between immunosuppression and the occurrence of the illness in the transplant recipients. Serologic testing failed to make a diagnosis in 1 patient with HME in the literature and in our patient with HGA, but molecular tests established the diagnosis in both cases. Tandem infection was observed in 1 patient with two episodes of HME 2 years apart. A high index of suspicion for tick-borne illnesses and appropriate prevention measures are needed for transplant patients with epidemiologic risk factors.

Zoonoses in Solid-Organ and Hematopoietic Stem Cell Transplant Recipients

Numerous reports exist of the transmission of zoonoses to humans during and after solid-organ and hematopoietic stem cell transplantation. Donor-derived infections of numerous etiologies, including West Nile virus infection, Chagas disease, toxoplasmosis, rabies, lymphocytic choriomeningitis virus infection, and infection due to Brucella species have been reported. Most zoonoses occur as a primary infection after transplantation, and immunocompromised patients are more likely to experience significant morbidity and mortality from these infections. Risks of zoonotic infection in the posttransplantation period could be reduced by patient education. Increased recognition of the risks of zoonoses, as well as the advent of molecular biology-based testing, will potentially augment diagnostic aptitude. Documented zoonotic infection as it affects transplantation will be the primary focus of this review.

Ehrlichia infection of the central nervous system

Ehrlichiosis in the United States is caused by three closely related bacterial species (Ehrlichia chaffeensis, Ehrlichia ewingii, and Anaplasma phagocytophilum), all transmitted through tick bite. Although there is variation with respect to geography and tick vector, the clinical manifestations are similar, and treatment of these infections is identical. Ehrlichiosis can present with a spectrum of neurologic manifestations, ranging in severity from headache to meningoencephalitis. Treatment is straightforward if the diagnosis is suspected, but antibiotic therapy should not be delayed pending laboratory confirmation. Doxycycline, the treatment of choice for adults and children with suspected ehrlichiosis, has high bioavailability and can be administered orally in most cases. Therapy is typically continued at least 3 days after the last documented fever. Although there have been no studies specifically evaluating duration or dosing of doxycycline for Ehrlichia meningoencephalitis, anecdotal reports suggest 100 mg doxycycline administered twice daily is effective, despite limited penetration into the cerebrospinal fluid. Because doxycycline interacts with CYP3A4 enzymes, there is potential for drug interactions with a number of medications. In endemic areas, documentation of coinfection with Borrelia burgdorferi, the etiologic agent of Lyme disease, may require prolonging the duration of doxycycline therapy.

Repression of rac2 mRNA expression by Anaplasma phagocytophila is essential to the inhibition of superoxide production and bacterial proliferation

Anaplasma phagocytophila, the etiologic agent of human granulocytic ehrlichiosis, is an emerging bacterial pathogen that invades neutrophils and can be cultivated in HL-60 cells. Infected neutrophils and HL-60 cells fail to produce superoxide anion (O(2)(-)), which is partially attributable to the fact that A. phagocytophila inhibits transcription of gp91(phox), an integral component of NADPH oxidase. cDNA microarray and RT-PCR analyses demonstrated that transcription of the gene encoding Rac2, a key component in NADPH oxidase activation, was down-regulated in infected HL-60 cells. Quantitative RT-PCR demonstrated that rac2 mRNA expression was reduced 7-fold in retinoic acid-differentiated HL-60 cells and 50-fold in neutrophils following A. phagocytophila infection. Rac2 protein expression was absent in infected HL-60 cells. Rac1 and Rac2 are interchangeable in their abilities to activate NADPH oxidase. HL-60 cells transfected to express myc-tagged rac1 and gp91(phox) from the CMV immediate early promoter maintained the ability to generate O(2)(-) 120 h postinfection. A. phagocytophila proliferation was severely inhibited in these cells. These results directly attribute the inhibition of rac2 and gp91(phox) transcription to the loss of NADPH oxidase activity in A. phagocytophila-infected cells and demonstrate its importance to bacterial intracellular survival.

Ehrlichiosis in children

Ehrlichia are obligate intracellular bacteria that belong to the family Rickettsiaceae. Human monocytic ehrlichiosis (HME) and human granulocytic ehrlichiosis (HGE) are the 2 ehrlichial diseases that are of greatest health concern in the United States. The agents causing HME and HGE are zoonotic pathogens requiring a mammalian reservoir and an arthropod vector. Differences in the geographic distribution of their tick vectors account for the concentration of HME in the South and southeastern United States and HGE in the Northeast and northern Midwest. Both infections have been reported in coastal regions from Rhode Island to Florida. HME and HGE are flulike illnesses that usually are self-limited but may be fatal. Diagnosis is confirmed by identification of the microorganism on blood smear or polymerase chain reaction or by detection of anti-ehrlichial antibody. Doxycycline is the antibiotic of choice for treatment of ehrlichiosis.