Cat-scratch disease: a rare cause of osteomyelitis.

Cat-scratch disease is a zoonosis caused by Bartonella henselae, characterised by regional lymphadenopathy. Rarer presentations, such as osteomyelitis, can occur.We present an adolescent girl with severe right lumbar pain and fever, without animal contacts or recent travels. On examination, pain on flexion of torso, movement limitation and marked lordosis were noted, but there were no inflammatory signs, palpable masses or lymph nodes. Serological investigations revealed elevated inflammatory markers. Imaging revealed a paravertebral abscess with bone erosion. Several microbiological agents were ruled out. After a second CT-guided biopsy, PCR for Bartonella spp was positive. At this point, the family recalled having a young cat some time before. Cat-scratch disease was diagnosed, and complete recovery achieved after treatment with doxycycline and rifampicin.Cat-scratch disease is a challenging diagnosis in the absence of typical features. However, B. henselae must be investigated if common pathogens are ruled out and response to therapy is poor.

Post-COVID reactivation of latent Bartonella henselae infection: a case report and literature review.

Cat scratch disease (CSD) is caused by Bartonella henselae (B. henselae) and presents as lymphadenopathy following close contact with cats. However, in context of the global COVID-19 pandemic, clinical manifestations of CSD may vary, posing new challenges for healthcare professionals. Here we describe a case of a 54-year-old male with painful left upper arm mass, which gradually resolved until he was infected with COVID-19. The mass then rapidly progressed before admission. Meanwhile, pulmonary symptoms including pleural effusion emerged simultaneously. The cause was undetermined with routine blood culture and pathological test until the next generation sequencing (NGS) confirmed the presence of B. henselae. We believe this case is the first to report localized aggravation of CSD after COVID-19 infection and hopefully, offers treatment experience for clinicians worldwide.

Variantes en la presentación clínica de la enfermedad por arañazo de gato en niños del hospital Garrahan / Variants in the clinical presentation of cat scratch disease in children at Garrahan Hospital

La infección por Bartonella henselae (BH) adopta diversas formas de presentación clínica en pediatría. Según la bibliografía la forma de presentación más frecuente en pacientes inmunocompetentes es la linfadenopatía única asociada a fiebre. En el 85 % de los casos se compromete un solo ganglio siendo los axilares y los epitrocleares los más frecuentemente involucrados. Existen otras formas de presentación menos frecuentes que debemos tener en consideración, para poder realizar un diagnóstico precoz e indicar un tratamiento adecuado si así lo requiere. El diagnóstico requiere de la sospecha clínica del equipo de salud tratante, junto al antecedente epidemiológico, los hallazgos clínicos del examen físico y la realización de serologías que incluyan el dosaje de inmunoglobulina M y G. Los objetivos del presente trabajo fueron reconocer las manifestaciones clínicas típicas y atípicas de la EAG por Bartonella henselae, describir la epidemiología, características clínicas y evolución de esta enfermedad que se presentaron en nuestro hospital. Se estudiaron un total de 187 pacientes. La media de edad fue de 7.6 años (rango 1-14); siendo 53.5% de género masculino. Las formas de presentación más frecuentes en nuestro trabajo fueron la adenitis y la fiebre. La mayoría recibió diversos esquemas de tratamiento antibiótico, secundario al retraso en el diagnóstico. La tasa de hospitalización fue muy baja, remitió con tratamiento ambulatorio con antibióticos o sin ellos (AU)

Bartonella henselae infection has different clinical presentations in pediatrics. According to the literature, the most common form of presentation in immunocompetent patients is single lymphadenopathy associated with fever. In 85 % of the cases a single lymph node is involved, with the axillary and epitrochlear nodes being the most commonly involved. There are other, less frequent, forms of presentation that should be taken into consideration in order to make an early diagnosis and indicate appropriate treatment if required. Diagnosis relies on clinical suspicion by the treating healthcare team, together with the epidemiological history, clinical findings on physical examination, and serology including immunoglobulin M and G dosage. The objectives of this study were to identify both the typical and atypical clinical manifestations of Bartonella henselae cat scratch disease, to describe the epidemiology, clinical characteristics, and outcomes of cases presenting at our hospital. A total of 187 patients were studied. The mean age was 7.6 years (range 1-14); 53.5% were male. The most frequent forms of presentation in our study were adenitis and fever. Most of them received different antibiotic treatment regimens due to delayed diagnosis. The hospitalization rate was very low and the disease typically resolved with outpatient treatment, with or without antibiotics (AU)

SEROLOGY NEGATIVE BARTONELLA NEURORETINITIS IN AN IMMUNOCOMPROMISED PATIENT.

BACKGROUND/PURPOSE: To report a case of serology-negative severe disseminated Bartonella neuroretinitis in an immunocompromised patient in which diagnosis was made by detection of B. henselae DNA by universal polymerase chain reaction of brain tissue. METHODS: Case report. RESULTS: A 57-year-old man with immunoglobulin A vasculitis on immunosuppressive therapy presented with lethargy, weight loss, and bilateral decreased vision. Fundus examination revealed bilateral mild vitritis, marked optic disc edema, vascular sheathing, and numerous white inner retinal and preretinal lesions. Brain magnetic resonance imaging revealed multiple foci of restricted diffusion and a ring-enhancing focus in the left parietal lobe. Serologies, cerebrospinal fluid, and vitreous biopsies were all negative for Bartonella. A brain biopsy was performed and B. henselae DNA was detected by universal polymerase chain reaction of the specimen. The patient demonstrated resolution of fundus findings with antibiotic treatment. Repeat serological testing demonstrated seroconversion. CONCLUSION: In immunocompromised patients, infection by Bartonella henselae can present as severe disseminated disease. Establishing the diagnosis can be challenging as serologic testing is often unrevealing in the setting of a blunted immune response. Polymerase chain reaction has been used in select cases to establish the diagnosis.

Bartonella infections diagnosed in the French reference center, 2014-2019, and focus on infections in the immunocompromised.

We studied retrospectively 651 PCR-confirmed Bartonella infections diagnosed at the French reference center for bartonellosis from 2014 to 2019. The most common form was cat-scratch disease (89%) followed by endocarditis (9%). Disseminated forms (2%) mainly presented as bacillary angiomatosis or peliosis hepatis in solid organ transplant recipients.

Systemic Cat-Scratch Disease: a "Troublesome" Diagnosis.

Diagnosis of systemic cat scratch disease may be challenging. Here, we describe a case of an immunocompetent girl exhibiting fever and multifocal hepatosplenic abscesses. Diagnostic tests for Bartonella henselae infection (enzyme immunoassay and polymerase chain reaction) were found steadily negative and the diagnosis, suspected on the basis of the Margilet's criteria, was finally confirmed by indirect immunofluorescent antibodies.

Bartonella osteomyelitis versus vertebral sarcoidosis: A tale of two cases.

BACKGROUND: Osteomyelitis is an uncommon manifestation of Bartonella henselae. Similarly, bony involvement may occur with sarcoidosis. Even though these are pathologically distinct entities, they can have overlapping imaging manifestations and therefore mimic one another. This is further complicated by the fact that both entities show non-caseating granulomatous inflammation on histopathology. We present two cases with similar imaging findings, with one case eventually diagnosed as Bartonella osteomyelitis, while the other proved to be vertebral sarcoidosis. Both patients exhibited vertebral involvement in common, and improved clinically and radiographically following antibiotics and steroids treatment, respectively. Given the overlapping pathological and imaging manifestations, and the non-specific clinical presentation, these entities may be considered in the differential consideration of each other. The presence of associated findings in such cases may be helpful.

Molecular and Serological Survey of the Cat-Scratch Disease Agent (Bartonella henselae) in Free-Ranging Leopardus geoffroyi and Leopardus wiedii (Carnivora: Felidae) From Pampa Biome, Brazil.

The genus Bartonella comprises emerging bacteria that affect humans and other mammals worldwide. Felids represent an important reservoir for several Bartonella species. Domestic cats are the main reservoir of Bartonella henselae, the agent of cat scratch disease (CSD). It can be transmitted directly by scratches and bites from infected cats and via cat fleas. This study aims to investigate the circulation of Bartonella spp. in free-ranging Neotropical wild felids from Southern Brazil using serological and molecular methods. In this study, 53 live-trapped free-ranging wild felids were sampled, 39 Leopardus geoffroyi and 14 Leopardus wiedii, from five municipalities in the Rio Grande, do Sul state, southern Brazil. All captured animals were clinically healthy. Two blood samples of L. geoffroyi were positive, by PCR, for the presence of B. henselae DNA. Conversely, none of L. wiedii blood samples were positive when tested using PCR. Indirect immunofluorescence assay (IFA) showed that 28% of serum samples of wild felids were reactive (seropositive) for B. henselae by immunofluorescence, with titers ranging from 64 to 256. The results presented here provide the first evidence of a Bartonella-enzootic cycle involving L. geoffroyi and L. wiedii, which may account for the spillover of the emerging zoonotic pathogen B. henselae for the indigenous fauna in Southern Brazil.

Molecular detection of Bartonella henselae, Bartonella clarridgeiae and Rickettsia felis in cat and dog fleas in Tenerife, Canary Islands, Spain.

The cat flea Ctenocephalides felis is the main vector of Bartonella henselae and Bartonella clarridgeiae, the causative agents of cat-scratch disease (CSD) and the spotted-fever agent Rickettsia felis. In spite of their worldwide distribution, there are no data on the occurrence of CSD-causing Bartonella species or the prevalence of Rickettsia species in the Canary Islands, Spain. Therefore, the aim of our study was to screen cat and dog fleas for both pathogens. A total of 128 C. felis from cats and dogs were screened for Bartonella and Rickettsia by PCR. Bartonella henselae (2.3%) and B. clarridgeiae (3.9%) were found in fleas infesting cats, whereas R. felis was identified in both cat (36.6%) and dog (40.7%) fleas. Further, co-infections were observed. This work constitutes the first finding of CSD-causing Bartonella species and the first study on the prevalence of R. felis in fleas from domestic animals in the Canary Islands. These results indicate public health importance, as associated infections could be misdiagnosed in the Archipelago despite their clinical relevance. Establishing human and animal routine diagnosis procedures for these pathogens along with improving vector control in shelters is necessary in order to prevent the spread of the infections among animals.

Analytical and clinical evaluation of new automated chemiluminescent immunoassays for the detection of IgG and IgM anti-Bartonella henselae antibodies.

Serological diagnosis of Bartonella henselae infection mainly rely on microscopic immunofluorescence assays (IFA), which are however time-consuming and poorly standardized. The aim of the study was to assess the use of the new fully automated VirClia® chemiluminescent immunoassays for the detection of IgG and IgM anti-B. henselae antibodies. Eighty-one patients with a well-defined B. henselae infection as well as 80 patients with an alternative disease were included. The VirClia® IgG antibody assay showed a sensitivity of 79.0% and a specificity of 93.8% for the diagnosis of B. henselae infection. For the VirClia® IgM assay, results were more conflicting with a sensitivity of 42.0% and a specificity of 98.2% to predict IFA IgM results. In 11 additional patients with uninterpretable IFA due to autoimmune antibodies, VirClia® assays were able to deliver valuable quantitative results. The VirClia® IgG assay shows good analytical and clinical performances and could be easily integrated in the diagnostic workflow of B. henselae infection.

A cat's scratch or a wolf's bite?

Bartonella henselae endocarditis mimicking systemic vasculitis has been reported in patients with valvulopathy. Herein, we describe a patient with B. henselae endocarditis involving a prosthetic pulmonic valve with positive anti-dsDNA antibodies misdiagnosed with systemic lupus erythematosus (SLE) based on the revised classification SLE criteria.

Scratching Past Lymphadenopathy: A Case of Bartonella henselae Encephalitis.

A previously healthy 6-year-old boy presented with new onset seizure activity and altered mental status. His prehospital course included prolonged fever, vague abdominal complaints, and unusual behavior. Neurological testing was unrevealing, and his symptoms slowly improved without intervention. His primary pediatrician had ordered serum antibody titers to Bartonella henselae for testing of prolonged fever in the setting of exposure to a kitten; these were found to be positive for both immunoglobulin G and immunoglobulin M. Further examination for organ involvement revealed splenic and liver micro-abscesses. After completion of his antibiotic course, the patient returned to his cognitive and neurologic baseline with resolution of his abdominal abscesses. This case emphasizes the importance of obtaining a thorough exposure history when evaluating for infectious causes of encephalitis. [Pediatr Ann. 2020;49(8):e359-e362.].

A case of Bartonella neuroretinitis with macular star diagnosed by clinical, epidemiological, serological, and molecular data: resolution after initiation of antimicrobial therapy.

The differential diagnosis of optic neuritis is broad and varied. We report the case of a 24-year-old Brazilian man who presented with five-week history of fever, malaise, myalgia, severe fatigue, tender right preauricular lymphadenopathy, and acute vision blurring associated with right optic disc swelling and exudates in a macular star pattern. His illness developed soon after an infestation of fleas broke out among his cats. Diagnosis of ocular bartonellosis was confirmed by serological and molecular analyses targeting amplification of Bartonella spp. htrA gene. Signs and symptoms only improved after initiation of antimicrobial therapy.

Hemophagocytic lymphohistiocytosis is associated with Bartonella henselae infection in a patient with multiple susceptibility genes.

BACKGROUND: Adult-onset hemophagocytic lymphohistiocytosis (HLH) is a rare and life-threatening condition, which is often triggered by certain types of infection, cancer and numerous autoimmune diseases; however, of the numerous infectious triggers associated with HLH, the consequences of Bartonella henselae infection have been rarely reported. CASE PRESENTATION: A 48-year-old female presented with a 20-day history of intermittent fever accompanied by systemic rash, fatigue, anorexia and weight loss later she developed shock and unconsciousness. Blood tests showed a reduction of leukocyte, anemia and thrombocytopenia, and pathological results of a bone marrow biopsy confirmed hemophagocytic activity. Metagenomic next-generation sequencing (mNGS) analysis of the lymph node detected the presence of B. henselae. Whole exome sequencing revealed two gene variants, STXBP2 and IRF5, in this adult patient with secondary HLH. Then, she received minocycline and rifampin combination anti-infective therapy. Intravenous immunoglobulin for 5 days followed by a high dose of methylprednisolone were also administered. The patient was successfully discharged from the intensive care unit and remained in good condition after 2 months of follow-up. CONCLUSIONS: mNGS served crucial roles in obtaining an etiological diagnosis, which suggested that screening for B. henselae should be considered in patients with HLH, especially those with a cat at home. In addition, the genetic defects were discovered to not only be present in primary HLH, but also in secondary HLH, even in the elderly.