Sequence typing of Bartonella henselae in small Indian mongooses (Urva auropunctata).

This study aimed to determine the sequence type (ST) of Bartonella henselae infecting small Indian mongooses from Saint Kitts via multi-locus sequence typing (MLST). This investigation used stored EDTA blood (n = 22) samples from mongooses previously identified as positive for B. henselae. Chocolate agar plates were enriched with Bartonella alpha-Proteobacteria growth medium (BAPGM) to culture and isolate Bartonella from the blood samples. To perform MLST, DNA was extracted and purified from isolates followed by amplification by conventional PCR (300-500 bp) for eight genes (16S rDNA, batR, gltA, groEL, ftsZ, nlpD, ribC, and rpoB). Bartonella henselae STs were deposited in the PubMLST repository. Out of 22 B. henselae-positive blood samples, isolates were obtained from 12 mongooses (54.5%; 12/22). Each mongoose was infected with one ST. The studied mongoose population was infected with sequence types ST2, ST3, ST8, and a novel ST represented by ST38. Bartonella henselae ST2, ST3 and ST8 infecting mongooses are known to circulate in humans and cats, with ST2 and ST8 associated with Cat Scratch Disease (bartonellosis) in humans. The results presented herein denote the circulation of B. henselae STs with zoonotic potential in mongooses with risk of B. henselae transmission to humans.

Seroprevalence of zoonotic pathogens in stray cats in an urban area of northeast Spain.

The feline population is extensive in urban areas worldwide, comprising stray and domestic cats. Cats, acting as reservoirs, can transmit various zoonotic organisms to humans, which can cause significant public health issues. We evaluated the seroprevalence of zoonotic pathogens in stray cats in an urban area of northeast Spain (the city of Zaragoza) to assess potential risks to human health. A total of 88 sampled cats (52 females and 36 males) underwent antibody evaluation using the indirect immunofluorescence technique. Seroprevalence rates were determined for IgG antibodies to Bartonella henselae (36.3%), Toxoplasma gondii (31.8%), Rickettsia felis (14.7%), Rickettsia typhi (9%), and Leishmania infantum (10.2%). Our results confirmed the presence in stray cats of antibodies against all those pathogens, indicating that they all circulate in the feline population in Zaragoza. Male cats exhibited a higher predisposition to T. gondii, whereas females showed an increased likelihood of contracting B. henselae. This difference may be attributed to distinct behaviors according to sex. Our findings underscore the importance of maintaining and intensifying surveillance coupled with preventive measures against zoonotic pathogens in cats. They highlight the need for comprehensive control strategies designed to mitigate public health risks associated with feline populations.

Paws and Pathogens: A Multidisciplinary Approach Through Bartonella henselae Endocarditis and Hepatosplenic T-Cell Lymphoma.

Bartonella species are gram-negative coccobacilli that are globally recognized as significant pathogens causing zoonotic infections. Among Bartonella species, B. henselae, B. quintana, and B. bacilliformis are prominent pathogens causing infections in humans, often manifesting as infective endocarditis. Bartonella endocarditis can pose diagnostic challenges due to its indolent presentation and limitations of standard microbiological culture techniques to identify the organism. We report a case of a 23-year-old male, who initially presented with the manifestations of hepatosplenic T-cell lymphoma, later diagnosed with blood culture-negative endocarditis caused by B. henselae. The patient had a complicated clinical course including pancytopenia, hepatosplenomegaly, and severe aortic valve regurgitation. Despite negative blood cultures, diagnostic clues included persistent fevers and bicuspid aortic valve with abscess. High Bartonella IgG titers (>1:800) supported the diagnosis. This case underscores the importance of considering Bartonella species in patients with suspected endocarditis, particularly in those with predisposing factors and negative blood cultures. Diagnosis relies heavily on serologic assays due to low sensitivity of conventional culture methods. Treatment involves a multidisciplinary approach with antibiotics and surgical intervention for optimal outcomes. Timely recognition and management are crucial to mitigate the high mortality associated with Bartonella endocarditis, and we hope this article offers insight for clinicians.

[Cat-scratch disease, clinical features in adults]. / Características clínicas de pacientes adultos con enfermedad por arañazo de gato.

INTRODUCTION: Cat-scratch disease (CSD) is caused by Bartonella henselae and it is under-recognized in adults because it mainly affects children. Clinical course is commonly benign and self-limited; occasionally, there may be systemic involvement. METHODS: Case-series study carried out in a tertiary care hospital in Buenos Aires suburbs. Patients older than 15 years diagnosed with CSD over a 5-year period were included (2016-2021). RESULTS: 30 adult patients were analyzed, with a median age of 20.5 years (IQR 17-29), 73% (n = 22) were male; 96% (n = 27) had history of exposure to cats. The most common clinical presentation of CSD was peripheral lymphadenopathy (90%), the average complication rate was 33% (n = 10), 86.7% (n = 26) received antimicrobial therapy, with a median duration of 5 days (IQR 5-10). Outcome was favorable in 83% (n = 25), 16% (n = 5) were lost to follow-up. DISCUSSION: Clinical features of CSD in adults are poorly described in the worldwide literature. Diagnosis can be challenging because the clinical hallmark is regional lymphadenopathy.

Introducción: La enfermedad por arañazo de gato (EAG) es producida por Bartonella henselae y debido a que afecta principalmente niños, es poco reconocida en adultos. El cuadro evolutivo es generalmente benigno y autolimitado, aunque ocasionalmente puede haber compromiso sistémico. Métodos: Estudio observacional, descriptivo y retrospectivo realizado en un hospital de tercer nivel del conurbano bonaerense. Se incluyeron pacientes mayores de 15 años con diagnóstico de EAG en un período de 5 años (2016-2021). Resultados: Se analizaron 30 pacientes adultos, con una mediana de edad de 20.5 años (17-29), el 73% (n = 22) fueron varones. El 96% (n = 27) presentó contacto estrecho con gatos. La presentación clínica más frecuente fue adenopatías periféricas (90%); el porcentaje de complicaciones fue de 33% (n = 10). La indicación de antibioticoterapia fue de 86.7% (n = 26), con una mediana de duración de 5 días (5-10). La evolución fue favorable en el 83% (n = 25), en el 16% (n = 5) se perdió seguimiento. Discusión: La EAG es poco reconocida en adultos; las características clínicas de este grupo etario se encuentran poco descriptas en la literatura. Es un desafío diagnóstico debido a que su forma de presentación más frecuente es la adenopatía localizada.

Parinaud's oculoglandular syndrome: Coinfection by Bartonella henselae and Sporothrix brasiliensis.

A 26-year-old woman presented an eyelid lesion, after being scratched by a cat that had a similar skin lesion. It evolved into a cervical lymph node enlargement. With a hypothesis of Parinaud´s oculoglandular syndrome (POS) due to cat scratch disease (CSD), doxycycline was prescribed. After two weeks of treatment without improvement, a biopsy and blood sample were obtained. Itraconazole was prescribed and the skin lesion improved, but not the lymph node enlargement. A Sporothrix schenckii complex was isolated from the skin sample. Also, a specie-specific polymerase chain reaction detected Bartonella henselae DNA in her blood sample. Azithromycin was included to treat the bacterial infection, whereupon the lymph node also receded successfully. Sporotrichosis and CSD are zoonoses that can be transmitted to humans by traumatic inoculation due to scratches or bites from cats. Both can evolve with POS. Patients who present skin lesions and/or POS after being wounded by a cat should be investigated for both diseases.

Development and Diagnostic Potential of a Novel Bartonella henselae-Specific Immunoglobulin.

Bartonella henselae is a gram-negative rod-shaped bacterium and is the primary causative agent of Cat Scratch Disease (CSD). Although the prevalence of CSD is low in the human population, the possibility of developing multi-organ complications, especially in vulnerable individuals, remains a serious cause for concern. The immunofluorescent assay (IFA) is currently one of the most common laboratory tests for the detection of antibodies to B. henselae in serum, however, it has several disadvantages. The enzyme-linked immunosorbent assay (ELISA) technique offers a more quantitative, sensitive, and cost-effective alternative to conventional IFAs. Here, we report the purification of a novel bioidentical polyclonal antibody from discarded human serum for use as a standard in ELISAs against B. henselae. This novel method of antibody production overcomes the many limitations of animal-derived antibodies while also offering a more robust, reproducible, and scalable antibody production alternative for the diagnosis of CSD.

First report of Bartonella henselae and Bartonella clarridgeiae carriage in stray cats from Ecuador and its link to a cat scratch disease outbreak in 2022.

INTRODUCTION: The genus Bartonella includes species and subspecies of fastidious, facultative intracellular Gram-negative bacilli that infect a wide variety of mammalian reservoirs including cats and humans. In 2022, the Ecuadorian Ministry of Health reported an outbreak of cat scratch disease caused by B. henselae in the city of Guayaquil. Therefore, we aimed to characterize the presence of Bartonella spp. in domestic and stray cats from the area of Guayaquil where the outbreak happened in 2022. METHODS: Whole blood samples of 100 domestic and stray cats were collected. Riboflavin synthase (ribC) and 16S rRNA genes detection was performed by PCR using Bartonella spp. specific primers, followed by Sanger sequencing and phylogenetic analysis. RESULTS: 14 cats were positive for Bartonella spp. carriage. Phylogenetic analysis confirmed the presence of 12 cats infected with B. henselae and 2 cats with B. clarridgeiae. CONCLUSIONS: There is a high prevalence of Bartonella spp. carriage in cats in the city of Guayaquil within the area where a recent cat scratch disease outbreak happened. Considering the high presence of cats and other domestic and stray animals in the city of Guayaquil, a One Health approach for surveillance and prevention of zoonotic diseases like cat scratch disease is needed.

Unusual presentation of cat scratch disease: case report.

Cat scratch disease (CSD) is an infection caused by Bartonella henselae, presents with non-specific symptoms like lymphadenopathy, fever, and fatigue. It can progress to disseminated disease, leading to complications such as liver and splenic micro abscesses, osteomyelitis, encephalitis, and uveitis. Diagnosis is challenging due to varied presentations and limited tests. Treatment involves supportive care, with severe cases requiring antimicrobial therapy. In this report, we present a case of Cat scratch disease characterized by an atypical clinical manifestation, hepatosplenic and paravertebral involvement.

Bartonella henselae DNA detection in patients with type 1 leprosy reactions for more than six months.

Leprosy reactions are among the main causes of physical disability resulting from an infectious disease and can culminate in irreversible physical disabilities, therefore they should be considered a clinical emergency, as well as the elucidation of its cause. Co-infections are considered one of the main triggering causes of leprosy reactions, aggravating and maintaining these reactions for longer in these patients. After reporting a high rate of Bartonella henselae infection in patients with chronic type 2 leprosy reaction, 19/47 (40.4 %) compared to the control group, 9/50 (18.0 %), p = 0.0149, we conducted this study to observe the rate of infection by Bartonella sp. in a group of patients with chronic type 1 leprosy reactions. Blood samples from 14 patients with chronic type 1 leprosy reactions were analyzed by molecular and microbiological tests and compared. The results showed that, like patients with chronic type 2 leprosy reactions, this group of patients has a high proportion of B. henselae infection 6/14 (42.9 %), p = 0.88. We conclude that these bacteria can trigger chronic leprosy reactions and should be investigated in all chronic leprosy reactions patients. Summary Line: Our results showed that, like patients with chronic type 2 leprosy reactions, this group of patients has the same proportion of B. henselae DNA detection 6/14 (42.9 %), p = 0.88.

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.

Unmasking Bartonella henselae infection in the shadows of long COVID thanks to clinical metagenomics.

The diagnosis of long COVID often relies on symptoms post-COVID-19, occasionally lacking biological evidence. This case study illustrates how investigating long COVID uncovered an underlying bartonellosis through clinical metagenomics. Following mild COVID-19, a 26-year-old woman experienced persistent symptoms during 5 months, including axillary adenopathy. Pathological examination, 16 S rRNA PCR, and clinical metagenomic analysis were done on an adenopathy biopsy. The latter revealed Bartonella henselae DNA and RNA. Treatment with clarithromycin improved symptoms. This case underscores the relevance of clinical metagenomics in diagnosing hidden infections. Post-COVID symptoms warrant thorough investigation, and bartonellosis should be considered in polyadenopathy cases, regardless of a recent history of cat or flea exposures.

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)

Endocarditis por bartonella asociada a glomerulonefritis y neurorretinitis / Bartonella endocarditis associated with glomerulonephritis and neuroretinitis

La endocarditis bacteriana con hemocultivo negativo constituye un dilema diagnóstico. Tanto Bartonella como Coxiella pueden causarla, con presentaciones clínicas similares que pueden simular una vasculitis sistémica no infecciosa. Sin embargo, difieren en el tipo y la duración del tratamiento, por lo que es fundamental identificar el agente etiológico. Presentamos un caso de endocarditis por Bartonella henselae asociada a glomerulonefritis y neurorretinitis, con hemocultivo negativo, anticuerpos anticitoplasma de neutrófilos y antiproteinasa 3 positivos, y serología positiva para Bartonella con reacción cruzada para Coxiella burnetti. El diagnóstico etiológico fue confirmado a posteriori mediante amplificación y secuenciación parcial del gen ribC a partir de tejido de la válvula cardíaca. El paciente recibió tratamiento antibiótico e inmunosupresor seguido de recambio valvular aórtico y presentó evolución favorable.

Blood-culture negative endocarditis is a diagnostic challenge. Both Bartonella and Coxiella can cause it with similar clinical presentations mimicking a systemic vasculitis. The identification of the etiologic agent is essential because they differ in treatment type and duration. We present a case of blood-culture negative endocarditis caused by Bartonella henselae, associated with glomerulonephritis and neuroretinitis, with negative blood culture, positive anti-neutrophil cytoplasmic and antiproteinase 3 antibodies. The serology was positive for Bartonella with cross-reactivity to Coxiella burnetti. The etiological diagnosis was achieved by polymerase chain reaction amplification and sequencing of a ribC gene fragment. The patient received antibiotic and immunosuppressive treatment followed by replacement of the aortic valve with favorable medium-term evolution.

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

Abstract 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.

Infectious endocarditis by Bartonella species: report of two cases / Endocarditis infecciosa por Bartonella: descripción de dos casos en Chile

ABSTRACT Infectious endocarditis (IE) by Bartonella species is an emerging problem worldwide. We report two cases of native valve Bartonella-associated IE events, both affecting adult male patients with a history of alcohol abuse and a low socioeconomic status. Admissions were due to pancytopenia and bleeding in one case and embolic stroke in the other. Blood cultures were negative and IgG indirect immunofluorescence assays (IFA) were positive for B. henselae/B. quintana in high titers (1/16,384-1/16,384, and 1/32,768 -1/16,384, respectively). Cases were classified as definitive IE events according to modified Duke criteria due to the presence of valve vegetations with at least three minor criteria. One patient required aortic mechanical valve replacement and survived, and the other died after a massive hemorrhagic transformation of his stroke. PCR amplification and sequencing of the 16S ribosomal bacterial DNA from a valve tissue sample obtained at surgery in the patient who survived, confirmed B. quintana as the etiological agent. Bartonella-associated IE is an emerging problem in Chile, present in disadvantaged populations. It should be suspected in patients with culture-negative IE. IFA does not discriminate between B. henselae and B. quintana infection, but high titers suggest IE. Complementary PCR techniques may help to elucidate the final causative agent.

La endocarditis infecciosa(EI) asociada a Bartonella es un problema emergente a nivel mundial. Publicamos los 2 primeros casos de EI en válvula nativa asociados a Bartonella en Chile, los que afectaron a pacientes masculinos con historia de consumo de alcohol y bajos ingresos. La hospitalización fue provocada por pancitopenia y hemorragias en un caso y por un evento cerebrovascular en el otro. Se solicitó serología para Bartonella por inmunofluorescencia indirecta (IFI) para ampliar el estudio ante hemocultivos negativos y en ambos casos se reportaron resultados intensamente positivos para B. henselae y B. quintana1/16.384-1/16.384 y 1/32.768 -1/16.384, respectivamente). Los casos se clasificaron como eventos definitivos de EI según los criterios modificados de Duke debido a la presencia de vegetaciones valvulares con al menos 3 criterios menores. Un paciente requirió reemplazo valvular aórtico y sobrevivió, y el otro falleció tras una transformación hemorrágica masiva del infarto cerebral. La amplificación del ADN ribosomal 16S por RCP y posterior secuenciación de una muestra de tejido valvular confirmó la presencia de B. quintana. La EI por Bartonella sp. es un problema emergente en Chile, probablemente asociada a poblaciones desfavorecidas, la que debe ser sospechada en pacientes con cultivos negativos. La IFI no permite discriminar infecciones por B. henselae o B. quintana pero los títulos altos sugieren EI. Técnicas complementarias por RCP pueden ayudar a dilucidar el diagnóstico.

Cat scratch disease presenting as axillary lymphadenopathy and a palpable benign mammary nodule mimicking a carcinoma

Abstract We present a case involving a 74-year-old woman with cat scratch disease characterized by an enlarged and hard axillary lymph node as well as a palpable breast nodule mimicking a carcinoma. The lymph node and the breast nodule were excised. The pathologic examinations revealed granulomatous lymphadenitis with gram-negative bacilli and an intraductal papilloma. Antibiotic therapy (azithromycin) was prescribed and the patient's clinical evolution was excellent.

Prevalencia de Bartonella henselae en donantes de sangre y riesgo de transmisión sanguínea en Chile / Prevalence of Bartonella henselae in blood donors and risk of blood transmission in Chile

Resumen Introducción: Bartonella henselae es el agente causal de la enfermedad del arañazo del gato en personas inmunocompetentes y de la angiomatosis bacilar y peliosis hepatis en inmunocomprometidos. En Chile la prevalencia de anticuerpos contra B. henselae en niños y adolescentes sanos es de 13,3%, en personas con riesgo ocupacional 60,5% y en gatos 85,6%. No existen datos publicados respecto de la seroprevalencia en donantes de sangre en nuestro país, por lo que determinar si B. henselae se encuentra presente en la sangre de los donantes al momento de la donación es muy importante, ya que este microorganismo puede sobrevivir hasta 35 días en los eritrocitos almacenados en banco de sangre a 4 °C. Objetivo: Determinar la prevalencia de B. henselae en donantes de sangre. Metodología: Se analizaron 140 muestras de sangre de donantes, para detectar la presencia de B. henselae, utilizando la técnica de la reacción de polimerasa en cadena (RPC). Resultados: Se obtuvo 13,6% de los donantes de sangre con RPC positiva para la B. henselae. La secuencia de los fragmentos amplificados presentó una identidad por sobre 98% con respecto a secuencias de B. henselae de referencia. Conclusión: El riesgo de transmisión sanguínea debiera ser considerado en un país con alta seroprevalencia de infección por B. henselae.

Background: Bartonella henselae is the causal agent of cat scratch disease in immunocompetent persons and bacterial angiomatosis in immunocompromised patients. In Chile, the prevalence of antibodies against B. henselae in healthy children and adolescents is 13.3%, in persons with occupational risk 60.5%, and in cats 85.6%. There are no published data regarding the seroprevalence in blood donors in our country, so determining if B. henselae is present in the blood of donors at the time of donation is very important, since this microorganism can survive up to 35 days in the red blood cells stored in a blood bank at 4 °C. Objective: To determine the prevalence of B. henselae in blood donors. Methodology: 140 donor blood samples were analyzed to detect the presence of B. henselae, using the polymerase chain reaction technique. Results: 13.6% of the blood donors with positive polymerase chain reaction for B. henselae were obtained. The sequence of the amplified fragments showed an identity of over 98% with respect to B. henselae reference sequences. Conclusion: The risk of blood transmission is due to a country with high B. henselae infection.

Osteomielitis vertebral por Bartonella henselae: a propósito de un caso / Bartonella henselae vertebral osteomyelitis: report of a case

Resumen: La enfermedad por arañazo de gato (EAG) causada por Bartonella henselae tiene prevalencia e incidencia desconocida en la población pediátrica chilena. La presentación como linfoadenopatía regional es la más frecuente, y sus formas atípicas constituyen un reto diagnóstico. Objetivo: Comunicar un caso de EAG con osteomielitis vertebral y entregar posibles lineamientos respecto al tratamiento. Cuadro clínico: Escolar de 8 años con síndrome febril prolongado y dolor dorsal con rigidez cervical. En estudio destaca IgG para Bartonella henselae positiva, ecotomografía abdominal con microabscesos esplénicos y resonancia magnética con lesiones vertebrales sugerentes de osteomielitis. Discusión: El diagnóstico de las formas atípicas requiere de un alto índice de sospecha, como en este caso, en que el paciente con síndrome febril manifiesta sintomatología musculoesquelética, lo que nos lleva a estudiar posibles complicaciones de la enfermedad. El conocimiento actual del tratamiento de EAG atípica o complicada se deriva de la observación de estudios de casos y no de ensayos aleatorios; se sugiere analizar de manera individual la terapia antimicrobiana y con ayuda de especialistas. Conclusión: Se discute y enfatiza la importancia de la alta sospecha clínica y se exponen algunas alternativas de tratamiento en función de la evidencia de la literatura actual.

Abstract: Cat scratch disease (CSD) is caused by Bartonella henselae, with unknown prevalence and incidence in the Chilean paediatric population. Regional lymphadenopathy is the most common presentation, while atypical forms constitute a diagnostic challenge. Objective: To report a case of CSD with osteomyelitis and present guidelines regarding treatment. Clinical case: An eight year-old patient, with prolonged febrile illness, back pain and neck stiffness. Laboratory studies highlight positive IgG for Bartonella henselae. The abdominal ultrasound showed splenic micro-abscesses, and the MRI showing vertebral lesions suggestive of osteomyelitis. Discussion: The diagnosis of atypical forms requires a high rate of suspicion, as in this case, in which the patient manifested the musculoskeletal symptoms simultaneously with the febrile syndrome, which led us to study possible complications of the disease. Current knowledge of the treatment of atypical or complicated CSD is derived from the observation of case studies, rather than randomized trials. It is suggested that antibiotic therapy is analysed individually, with the help of a specialist. Conclusion: The importance of high clinical suspicion are emphasised and discussed, as well presenting some treatment options based on the evidence from the current literature.