Autoimmune haemolytic anaemia triggered by Bartonella henselae infection: a case report

"Let the Cat Out of the Heart": Clinical Characteristics of Patients Presenting With Blood Culture-Negative Endocarditis Due to Bartonella Species

Patients with blood culture-negative endocarditis due to Bartonella infection frequently presented with fever, cytopenias, kidney failure, and positive PR3-ANCA. Bartonella IgG titers were variable. Patients commonly underwent surgery with overall low mortality.

Autoimmune Thyroiditis Induced by <b><i>Bartonella henselae</i></b> (Cat-Scratch Disease) Might Be Reversible

<b><i>Introduction:</i></b> <i>Bartonella henselae</i> infection leads to development of cat-scratch disease (CSD) but may also trigger of autoimmune thyroiditis (AIT). <b><i>Case Presentation:</i></b> We describe a 4-year-old boy with a severe fever of unknown etiology, disseminated neck lymphadenopathy, and a headache. Treatment with antibiotics was employed, but finally a left tonsillectomy, selective left lymphadenectomy, and immunophenotyping were performed to exclude lymphoma. Histologic examination excluded lymphoma but revealed CSD. IgG against <i>B</i>. <i>henselae</i> and <i>Bartonella quintana</i> was positive. A goiter was also found and positive anti-thyroid antibodies confirmed AIT. Two months later, the thyroid was not palpable, normal on ultrasound, and both anti-thyroid antibodies were negative. The full reversibility was documented, and 6-year follow-up showed that the patient remains disease free. <b><i>Conclusion:</i></b> This is the first report that AIT triggered by <i>B</i>. <i>henselae</i>/<i>B</i>. <i>qunitana</i> might be reversible if the pathogenetic factor is eliminated at an early stage of disease.

Treatment of a cat with presumed Bartonella henselae-associated immune-mediated hemolytic anemia, fever, and lymphadenitis

A 2.5‐year‐old castrated male cat presented with fever and marked generalized lymphadenopathy of 4‐months duration, despite treatment with amoxicillin‐clavulanate/marbofloxacin. Abnormalities were not detected on complete blood count, serum chemistry, and FIV/FeLV test apart from a borderline, non‐regenerative anemia. Peripheral lymph node fine needle aspirations revealed a marked increase in the percentage of intermediate‐ and lymphoblastic‐lymphocytes in addition to reactive macrophages. Three weeks after presentation, the cat developed a severe, regenerative, immune‐mediated hemolytic anemia (IMHA) which responded to immunosuppressive therapy. Fever and lymphadenopathy persisted. Peripheral lymph nodes tested positive for Bartonella henselae DNA in real‐time PCR assay and sequencing. Treatment with pradofloxacin and doxycycline resulted in resolution of clinical signs, and negative PCR tests. Despite its reported low pathogenicity, B. henselae infection should also be considered in cats with protracted unexplained fever, lymphadenitis, and IMHA. Furthermore, a combination of pradofloxacin and doxycycline might be considered in cats with bartonellosis given its apparent clinical efficacy.

Associations between presence of Bartonella species deoxyribonucleic acid and complete blood cell count and serum biochemical changes in client-owned cats

Background

Infection with Bartonella species is common in cats but reported effects of bacteremia on laboratory variables differ.

Objectives

Evaluate for associations between Bartonella bacteremia and CBC and serum biochemical changes in sick and healthy cats throughout the United States.

Animals

A total of 3964 client‐owned cats.

Methods

Retrospective cohort study using submissions to a commercial laboratory between 2011 and 2017. Serum biochemistry and CBC abnormalities (categorized as above or below reference intervals), age, and location (high‐ or low‐risk state for Ctenocephalides felis) in presumed healthy and sick cats were evaluated for associations with presence of Bartonella spp. DNA, detected by PCR. Univariate and multivariable logistic regression analyses were performed.

Results

Bartonella spp. DNA was amplified from 127 (3.2%) of 3964 cats; 126 (99.2%) of 127 were from high flea risk states and 121 (95.3%) of 127 were presumed sick. Fever of unknown origin was the most common PCR panel requested. In the multivariable analysis, neutrophilia, decreased ALP activity, clinical status (presumed sick), and young age (≤2 years) each were positively associated whereas neutropenia and hyperproteinemia both were negatively associated with Bartonella spp. bacteremia. Presence of Bartonella spp. DNA had no association with test results for other infectious disease agents.

Conclusions and Clinical Importance

In both healthy and sick cats, active Bartonella infections had minimal association with clinically relevant laboratory abnormalities. However, based on these results, in areas considered high risk for C. felis, active infection with Bartonella spp. is a reasonable differential diagnosis for cats presented with unexplained fever and neutrophilia, particularly if the cat is young.

Anorexia Nervosa Caused by Polymicrobial Tick-Borne Infections: A Case Study

The etiology of anorexia nervosa (AN) is multifactorial, and infections may play a contributory and possibly a prominent role. A case is presented which is indicative of a causal association between tick-borne infections and AN. This adolescent female was diagnosed with AN at an eating disorder clinic after excessive food restriction and an irrational fear of weight gain necessitating nasogastric tube feeding. Her history was consistent with systemic infections and she tested serologically positive to Borrelia burgdorferi, Babesia microti, and Mycoplasma pneumoniae; in addition, her clinical presentation was consistent with a Bartonella infection. After treatment with oral and intravenous antimicrobials, she stopped food restriction and no longer had body image concerns. Physicians should be aware of the possibility that tick-borne infections could underly a diagnosis of AN. The role of tick-borne infections in the etiology of AN warrants further study.

Is Bartonella a Cause of Primary Sclerosing Cholangitis? A Case Study

The etiology of primary sclerosing cholangitis (PSC) is unknown. I present a case which may be indicative of a causal link between Bartonella infection and PSC. The patient presented with complaints of abdominal pain and bloody diarrhea. A colonoscopy demonstrated chronic inflammation and changes consistent with ulcerative colitis. Routine laboratory studies revealed elevated liver function tests (LFTs); ultrasound and magnetic resonance imaging (MRI) confirmed the diagnosis of PSC. Bartonella serology was positive. It is established that Bartonella infection is associated with both gastrointestinal inflammation and autoimmunity; indeed, there is an animal model for Bartonella-induced PSC. Bartonella is susceptible to treatment with vancomycin and there are case reports and small series that demonstrate that PSC responds to treatment with oral vancomycin. Because of this, it is postulated that at least some cases of PSC may be associated with Bartonella infection. The patient in this report was treated with oral vancomycin and, since then, has been in remission for both colitis and PSC. Since vancomycin is not systemically absorbed, the premise is that he suffered from Bartonella colitis and an autoimmune reaction to Bartonella causing PSC. This premise warrants further study.

Bartonella endocarditis in a child with tetralogy of Fallot complicated by PR3-ANCA positive serology, autoimmune hemolytic anemia, and acute kidney injury

Although the role of ANCA in infective endocarditis is unclear, Bartonella henselae has been implicated as the culprit in cases of PR3-ANCA positive subacute bacterial endocarditis (SBE) with glomerulonephritis. In this case, a Coombs-positive autoimmune hemolytic anemia and glomerulonephritis accompanied a PR3-ANCA positive SBE caused by Bartonella henselae.

Bartonella Species, an Emerging Cause of Blood-Culture-Negative Endocarditis

Since the reclassification of the genus Bartonella in 1993, the number of species has grown from 1 to 45 currently designated members. Likewise, the association of different Bartonella species with human disease continues to grow, as does the range of clinical presentations associated with these bacteria. Among these, blood-culture-negative endocarditis stands out as a common, often undiagnosed, clinical presentation of infection with several different Bartonella species. The limitations of laboratory tests resulting in this underdiagnosis of Bartonella endocarditis are discussed. The varied clinical picture of Bartonella infection and a review of clinical aspects of endocarditis caused by Bartonella are presented. We also summarize the current knowledge of the molecular basis of Bartonella pathogenesis, focusing on surface adhesins in the two Bartonella species that most commonly cause endocarditis, B. henselae and B. quintana. We discuss evidence that surface adhesins are important factors for autoaggregation and biofilm formation by Bartonella species. Finally, we propose that biofilm formation is a critical step in the formation of vegetative masses during Bartonella-mediated endocarditis and represents a potential reservoir for persistence by these bacteria.

Bartonella henselae infection presenting with a picture of adult-onset Still's disease

We report a patient with a clinical picture of suggestive for adult-onset Still's Disease (ASOD) due to Bartonella infection. A 42-year-old immunocompetent man was admitted with fever, rash, arthralgia and sore throat. As his clinical picture suggested ASOD except unusual skin manifestation, we treated him on steroid and ibuprofen. His fever and constitutional symptoms responded immediately within 24hrs of commencing therapy, yet rash and leukocytosis remained. Meanwhile, Bartonella infection was proved by culture of bone marrow. Minocyclin treatment started combined with hydroxychloroquine sulfate and the patient discharged with overall improvement.

Bartonella henselae initial infection of mature human erythrocytes observed in real time using bacterial endogenous fluorescence

Bartonella henselae is a causative agent of anemia, cat scratch disease, bacillary angiomatosis, recurrent fever, hepatitis, endocarditis, chronic lymphadenopathy, joint and neurological disorders. B. henselae are intra-erythrocytic bacteria. The goal of this study was to visualize the B. henselae invasion into enucleated human red blood cells in real time using bacterium endogenous fluorescence. We took advantage of the unique fluorescence emission spectral profile of the bacteria. We used a linear unmixing approach to separate the fluorescence emission spectra of human erythrocytes from native B. henselae when excited at 488nm. Human blood samples were inoculated with B. henselae and incubated for 60 hours. 3-D live images were captured at select intervals using multi-photon laser scanning microscopy. Uninfected blood samples were also analyzed. This study revealed bacteria entering mature erythrocytes over a 60 hour time period.

Atypical manifestation of cat‐scratch disease: isolated epigastric pain in an immunocompetent, 12‐year‐old child

We present a 12-year-old immunocompetent girl with hepato splenic cat-scratch disease (CSD). Her sole inaugural complaint was isolated epigastric pain. She fully recovered, with normalized abdominal CT scan following 2 weeks course of Azythromycin®. CSD should be included in differential diagnosis in children with epigastric pain, especially in those with domestic pets.

Bartonella henselae infection associated with autoimmune thyroiditis in a child

BACKGROUND

Bartonella henselae was discovered a quarter of a century ago as the causative agent of cat-scratch disease. More recently, Bartonella has been found to be responsible for a broad range of clinical syndromes (prolonged fever, hepatosplenic disease, encephalopathies, ocular disease) and associated with autoimmune conditions.

CASE

This is the first report of autoimmune thyroiditis related to B. henselae infection. We describe an 11-year-old boy who presented with goiter and weight loss. At the time of admission a 2 × 1 cm mildly tender right supraclavicular lymph node was noted in association with an erythematous papule at the same side of the neck. We describe an association of autoimmune hyperthyroidism (Hashitoxicosis) with B. henselae infection (cat-scratch disease) in a pediatric patient.

CONCLUSION

Different types of infections are implicated in the pathogenesis of autoimmune thyroid disease through molecular mimicry or other mechanisms, despite their role is disputed. We speculated that autoimmune thyroiditis should be added to the spectrum of clinical syndromes that can be triggered by B. henselae.

Bartonella henselae infection in a family experiencing neurological and neurocognitive abnormalities after woodlouse hunter spider bites

BACKGROUND

Bartonella species comprise a group of zoonotic pathogens that are usually acquired by vector transmission or by animal bites or scratches.

METHODS

PCR targeting the Bartonella 16S-23S intergenic spacer (ITS) region was used in conjunction with BAPGM (Bartonella alpha Proteobacteria growth medium) enrichment blood culture to determine the infection status of the family members and to amplify DNA from spiders and woodlice. Antibody titers to B. vinsonii subsp. berkhoffii (Bvb) genotypes I-III, B. henselae (Bh) and B. koehlerae (Bk) were determined using an IFA test. Management of the medical problems reported by these patients was provided by their respective physicians.

RESULTS

In this investigation, immediately prior to the onset of symptoms two children in a family experienced puncture-like skin lesions after exposure to and presumptive bites from woodlouse hunter spiders. Shortly thereafter, the mother and both children developed hive-like lesions. Over the ensuing months, the youngest son was diagnosed with Guillain-Barre (GBS) syndrome followed by Chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP). The older son developed intermittent disorientation and irritability, and the mother experienced fatigue, headaches, joint pain and memory loss. When tested approximately three years after the woodlouse hunter spider infestation, all three family members were Bartonella henselae seroreactive and B. henselae DNA was amplified and sequenced from blood, serum or Bartonella alpha-proteobacteria (BAPGM) enrichment blood cultures from the mother and oldest son. Also, B. henselae DNA was PCR amplified and sequenced from a woodlouse and from woodlouse hunter spiders collected adjacent to the family's home.

CONCLUSIONS

Although it was not possible to determine whether the family's B. henselae infections were acquired by spider bites or whether the spiders and woodlice were merely accidental hosts, physicians should consider the possibility that B. henselae represents an antecedent infection for GBS, CIDP, and non-specific neurocognitive abnormalities.

Intruders below the radar: molecular pathogenesis of Bartonella spp

Bartonella spp. are facultative intracellular pathogens that employ a unique stealth infection strategy comprising immune evasion and modulation, intimate interaction with nucleated cells, and intraerythrocytic persistence. Infections with Bartonella are ubiquitous among mammals, and many species can infect humans either as their natural host or incidentally as zoonotic pathogens. Upon inoculation into a naive host, the bartonellae first colonize a primary niche that is widely accepted to involve the manipulation of nucleated host cells, e.g., in the microvasculature. Consistently, in vitro research showed that Bartonella harbors an ample arsenal of virulence factors to modulate the response of such cells, gain entrance, and establish an intracellular niche. Subsequently, the bacteria are seeded into the bloodstream where they invade erythrocytes and give rise to a typically asymptomatic intraerythrocytic bacteremia. While this course of infection is characteristic for natural hosts, zoonotic infections or the infection of immunocompromised patients may alter the path of Bartonella and result in considerable morbidity. In this review we compile current knowledge on the molecular processes underlying both the infection strategy and pathogenesis of Bartonella and discuss their connection to the clinical presentation of human patients, which ranges from minor complaints to life-threatening disease.

Beyond cat scratch disease: widening spectrum of Bartonella henselae infection

Bartonella henselae was discovered a quarter of a century ago as the causative agent of cat scratch disease, a clinical entity described in the literature for more than half a century. As diagnostic techniques improve, our knowledge of the spectrum of clinical disease resulting from infection with Bartonella is expanding. This review summarizes current knowledge regarding the microbiology, clinical manifestations, diagnostic techniques, and treatment of B. henselae infection.

Bone marrow and skin granulomatosis in a patient with Bartonella infection

This report describes a case of granulomatous inflammation, involving the bone marrow and skin, due to Bartonella infection in an immunocompetent patient. The clinical presentation included prolonged fever, pancytopenia, rash and hepatitis. Bartonella infection should thus be added to the growing list of entities that produce marrow granulomas and fever.

Prevalence of Mycoplasma haemofelis, 'Candidatus Mycoplasma haemominutum', Bartonella species, Ehrlichia species, and Anaplasma phagocytophilum DNA in the blood of cats with anemia

Hemoplasmas are known causes of anemia in some cats and some Bartonella species have been associated with anemia in people and in dogs. In this retrospective study, we used polymerase chain reaction (PCR) assays to determine the prevalence rates of Mycoplasma haemofelis, ‘Candidatus M haemominutum’, A phagocytophilum, Ehrlichia species, and Bartonella species DNA in the blood of cats with anemia and a control group of healthy cats. DNA of the organisms was amplified from 22 of 89 cats with anemia (24.7%) and 20 of 87 healthy cats (23.0%). DNA of a hemoplasma was amplified from 18 of 89 cats with anemia (20.2%) and 13 of 87 healthy cats (14.9%); DNA of a Bartonella species was amplified from five of 89 cats with anemia (5.6%) and seven of 87 healthy cats (8.0%). There were no statistically significant differences detected between groups.

The Expanded Spectrum of Bartonellosis in Children

Bartonella spp cause various clinical syndromes immunocompetent and immunocompromised hosts. Domestic cats are the natural reservoir, and vectors of B henselae. B henselae infection usually occurs early in childhood, is generally asymptomatic, and in most cases revolves spontaneously. It may, however, produce a wide spectrum of clinical symptoms, the most frequent feature being cat-scratch disease. Disseminated atypical B. henselae infection may follow cat-scratch disease alter a symptom-free period or may present de novo mimicking a wide range of clinical disorders. A careful clinical history researching an intimate contact with a kitten associated with a specific serology and an abdominal ultrasound for typical hepatosplenic involvement may follow a rapid and accurate diagnosis.

Enfermedades producidas por Bartonella spp

The genus Bartonella is cause of a broad number of emerging and re-emerging infectious diseases. Clinical manifestations depend on the implicated Bartonella sp. and the immunity of the host. Because there is not a universal therapy for this infection, treatment should be chosen individually. Bartonella sp. is responsible of potentially serious clinical pictures (endocarditis, chronic bacteremia, bacillary angiomatosis, Carrion's disease, etc.), so clinical suspicion, a quick diagnosis and an early treatment provide a better resolution.