Bartonella Henselae Infection Research Articles

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.

Application of metagenomic next-generation sequencing in the diagnosis of Bartonella neuroretinitis: a case report and literature review.

Cat-scratch disease (CSD) is caused by Bartonella henselae infection. In atypical cases of CSD, pathogen determination is challenging. We report a case of Bartonella neuroretinitis with neither a clear history of scratches nor typical general symptoms. The diagnosis was made using metagenomic next-generation sequencing (mNGS), a high-throughput sequencing technology. A female patient presented to the ophthalmologist with complaint of blurred vision in her right eye. Although with history of raising a cat, she reported no clear history of scratches or typical general symptoms, except a fever of unknown origin which resolved spontaneously. The best corrected visual acuity (BCVA) of the right eye was count fingers. Fundus examination showed optic disc oedema, macular exudates and inferior exudative retinal detachment. Laboratory examination results showed increased value of serum C-reactive protein and erythrocyte sedimentation rate. Ocular involvement of toxoplasmosis, syphilis and tuberculosis were excluded. To identify the possible causative pathogen of the disease, mNGS of aqueous humour sample was performed and 521 reads of B. henselae were identified. Serological test results further showed a positive immunoglobulin G (IgG) titre of 1:64. Taking the contact history, clinical manifestations, mNGS and serological results into consideration, the diagnosis of Bartonella neuroretinitis (ocular CSD) was made. After appropriatetreatment, the BCVA of the right eye improved to 20/25 in the last follow-up. Fundus examination showed a normal optic disc and macula, and the exudates had reduced. mNGS, a fast and unbiased method, can be used to detect B. henselae (if present) in intraocular fluid samples.; however, the results should be interpreted together with the clinical symptoms and other auxiliary test results.

A Retrospective Analysis of Systemic Bartonella henselae Infection in Children.

Systemic Bartonella henselae infection, also known as cat-scratch disease (CSD), presents a diagnostic challenge due to the variability of clinical manifestations and the potential for serological cross-reactivity with other organisms. This study aimed to retrospectively analyze the epidemiological, clinical, laboratory, and imaging characteristics of pediatric patients diagnosed with systemic B. henselae infection, to improve understanding and facilitate timely diagnosis and treatment. We conducted a 10-year retrospective study at the "Louis Turcanu" Children's Emergency Hospital and private clinics in Timisoara, Romania, reviewing records for confirmed cases of B. henselae infection from January 2014 to January 2024. The study adhered to the Declaration of Helsinki and received approval from the Institutional Review Board. Diagnostic criteria included contact with animals, prolonged fever, hematological and/or hepatosplenic manifestations, and positive serological tests for B. henselae. Nineteen pediatric patients were identified with a median age of 8.1 years. The majority were exposed to felines (94.7%), reflecting the disease's epidemiological profile. Clinical findings highlighted fever (47.4%), lymphadenopathy (78.9%), and less frequently, abdominal pain and headache (both 10.5%). Laboratory analyses revealed a mean hemoglobin of 12.6 mg/dL, WBC count of 13.1 × 103 cells/microliter, and platelet count of 340.6 × 103 per microliter. Significant findings included elevation in ESR and CRP in 47.4% and 21.1% of patients, respectively, and high seropositivity rates for B. henselae IgM (63.2%) and IgG (94.7%). Imaging studies demonstrated widespread lymphadenopathy and occasional splenomegaly and hepatic microabscesses. All patients received antibiotic therapy, with azithromycin being the most commonly used (94.7%). Co-infections with Epstein-Barr Virus, Cytomegalovirus, and Toxoplasma gondii were documented, indicating the complex infectious status of the patients. Systemic B. henselae infection in children predominantly manifests with fever and lymphadenopathy, with a significant history of exposure to felines. Laboratory and imaging findings support the diagnosis, which is further complicated by potential co-infections. Effective antibiotic therapy, primarily with azithromycin, underscores the need for comprehensive diagnostic and treatment strategies. This study emphasizes the importance of considering systemic B. henselae infection in pediatric patients with prolonged fever and contact with cats, to ensure timely and appropriate treatment.

Bartonella henselae as a putative trigger for chronic type 2 leprosy reactions

Leprosy reactions are an acute inflammatory phenomenon that can arise before diagnosis, during treatment, or after cure of leprosy. These reactions are considered one of the main diseases that cause physical disabilities. Immunosuppressive treatment for these immune responses makes these patients susceptible to coinfections, which can trigger new leprosy reactions. The main objective of this study was to evaluate the occurrence of infection by Bartonella sp. in blood samples from 47 patients who had untreatable episodes of type 2 leprosy reactions for more than six months, comparing them with a control group. Cultures and molecular methods (PCR) were used. Amplicons from species-specific reactions and sequencing showed a higher prevalence of Bartonella henselae infection in patients, 19/47 (40.4 %), compared to control, 9/50 (18.0 %), p = 0.0149. Five patients accepted treatment for coinfection, and all showed improvement in leprosy reactions with treatment for B. henselae infection. We conclude that these bacteria can trigger chronic reactions of type 2 leprosy and should be investigated in these patients. Summary linePatients who have chronic type 2 leprosy reactions are more susceptible to Bartonella henselae infection than controls: 19/47 (40.4 %) compared 9/50 (18.0 %), p = 0.0149.

Hemophagocytic lymphohistiocytosis secondary to unrecognized Bartonella henselae infection: a case report

BackgroundBartonella henselae is a species of intracellular bacteria transmitted to humans through animal bites and scratches contaminated with the feces of arthropod vectors, and are most commonly associated with cat exposure although transmission from other mammals has been reported. Bartonella henselae infection has a spectrum of clinical manifestations and has rarely been reported as cause of hemophagocytic lymphohistiocytosis (HLH) in immunocompromised hosts.Case presentationWe present a report of Bartonella henselae infection progressing to HLH in an immunocompetent patient. The patient initially presented with regional lymphadenopathy but the diagnosis was not suspected as the patient reported no exposure to cats. On further history, he did report a scratch from a dog prior to development of symptoms. The patient was treated with methylprednisolone, intravenous immunoglobulin and anakinra for the HLH and three months of Doxycycline for Bartonella infection, with complete resolution of symptoms.ConclusionsAlthough commonly associated with cat exposure, Bartonella henselae transmission can occur after exposure to other animals and vectors including dogs and clinicians need to maintain an index of suspicion for timely diagnosis. Bartonella henselae is associated with a spectrum of clinical manifestations which can include disseminated infection with severe complications such as hemophagocytic lymphohistiocytosis. Prompt initiation of Bartonella treatment is essential when thought to be the trigger for hemophagocytic lymphohistiocytosis although the optimal treatment regimen is unclear.

Acute Hepatitis by Bartonella henselae Infection in an Adult Patient with Decompensated Liver Cirrhosis

Hepatitis caused by Bartonella henselae in adults is a condition that is seldom reported in the literature, as well as its current incidence and prevalence. While there is a broad spectrum of well-defined and established clinical entities, hepatic involvement represents the third most frequent clinical manifestation of infection by this genus of bacteria. It may or may not be characterized by the presence of hepatosplenic granulomas. Diagnosis requires a high level of clinical suspicion, exclusion of additional etiologies, and a causal relationship with risk factors. Polymerase chain reaction is the diagnostic test with the highest diagnostic yield, and treatment varies depending on the clinical expression. We describe the case of an adult patient with hepatitis secondary to Bartonella henselae infection.

Cat-scratch disease manifesting as uveitis and binocular fundus nodular lesions: a case report

BackgroundCat-scratch disease typically presents with various ocular manifestations such as uveitis, vitritis, retinitis, retinochoroiditis, and optic neuritis. However, fundus nodular lesions was rarely reported. In our study, we reported a case of Cat-Scratch disease with binocular fundus nodular lesions.Case presentationAn 11-year old male presented with uveitis in the right eye and bilateral fundus nodular lesions after indirect contact with unvaccinated cats. Comprehensive ancillary examinations including wide-angle fundus photography, ultrasonography, fluorescein fundus angiography, optical coherence tomography, and orbital magnetic resonance imaging were performed to elucidate the multidimensional features of the binocular lesions. Metagenomics next-generation sequencing was utilized to confirm the diagnosis of Cat-scratch disease. The patient’s condition showed improvement after a 6-month combination treatment regimen involving systemic administration of doxycycline hyclate and methylprednisolone tablets, as well as local application of mydriatic and corticosteroid eye drops.ConclusionsWe firstly reported a case of Cat-scratch disease presenting simultaneously with uveitis and fundus nodular lesions caused by Bartonella henselae infection in a child. Timely diagnosis and treatment with antibiotics and corticosteroids showed promising outcomes for the prognosis of these ocular disorders.

Central retinal vein occlusion associated with Bartonella henselae infection

PurposeTo report the clinical features and treatment course of a case of central retinal vein occlusion (CRVO) as the initial sign of ocular Bartonella henselae (B. henselae) infection.ObservationA 36-year-old male was evaluated for unilateral vision loss. He denied prodromal symptoms but reported prior exposure to fleas. Best corrected visual acuity (BCVA) was 20/400 in the left eye. Clinical examination revealed a CRVO with atypical features including significant peripapillary exudates and peripheral vascular sheathing. Laboratory testing revealed elevated B. henselae IgG titers (1:512) with no abnormalities on hypercoagulability testing. The patient was treated with doxycycline and aflibercept with an excellent clinical response and improvement in BCVA to 20/25 in the left eye two months later.ConclusionCRVO is a rare but sight-threatening complication of ocular bartonellosis and can be the presenting sign of infection, even in the absence of cat exposure or prodromal symptoms.

Utility of Polymerase Chain Reaction Versus Serology-Based Testing in Immunocompromised Patients With Bartonella henselae Infection.

Bartonella henselae serologies can be nondiagnostic in immunocompromised individuals due to impaired humoral immunity. Blood polymerase chain reaction (PCR) is more useful diagnostically in immunosuppressed persons. We discuss 3 cases: 2 solid organ transplant (SOT) recipients and 1 person with human immunodeficiency virus (HIV) with positive blood PCR despite negative serology.

Vogt‐Koyanagi‐Harada disease following a serology‐proven Bartonella henselae retinitis: A case report

AbstractPurpose: To report a case of Vogt‐Koyanagi‐Harada (VKH) disease following a serology‐confirmed bartonella henselae retinitis.Methods: A single case report.Results: A 41‐year‐old female patient presented with a central scotoma in her right eye (RE). Fundoscopic examination showed a focal retinitis with a macular star in the RE. Work‐up revealed positive bartonellosis serology. The patient was treated with oral azithromycine and oral steroids during 4 weeks with subsequent healing of the retinitis lesion. Three months after initial presentation, the patient complained of loss of vision in both eyes. Ophthalmological examination showed a best‐corrected visual acuity (BCVA) of 20/200 on both eyes, with a bilateral granulomatous panuveitis with bilateral multifocal exudative retinal detachment. Results of multimodal imaging were consistent with the diagnosis of acute VKH disease.Given the history of positive bartonellosis serology, the patient was treated with doxycycline (200 mg/day) for 6 weeks in association with intravenous methylprednisolone for 5 days followed by oral steroids and progressive tapering. At three‐month follow‐up, BCVA improved to 20/20 in both eyes associated with resolution of clinical and structural OCT changes.Conclusions: Our case suggests that bartonella henselae infection might be a non‐previously reported infectious trigger of VKH disease in genetically predisposed patients. Alternatively, bartonella henselae infection might manifest with panuveitis mimicking VKH disease.

Cat Scratch Disease in Children

The aim of this paper is to provide information on the clinical manifestations, diagnosis and treatments of Bartonella henselae infection in children. Cat scratch disease (CSD) is a zoonosis caused by Bartonela henselae. Cat fleas are responsible for spreading the bacterium among cats. Bacteria can be transmitted to humans from the site of a cat bite or scratch. The typical manifestation of CSD is regional lymphadenopathy with a pustule at the site of inoculation, usually self-limiting. Atypical CSD has a wide range of clinical manifestations (hepatosplenic disease, pulmonary infiltrates, encephalitis, skin or bone involvement, endocarditis), some of which are life-threatening. Atypical presentations mainly occur in immunocompromised children, but have also been described in immunocompetent children.Conclusion − In recent years the number of households with a pet is growing and the number of children visiting a pediatrician with CSD is growing.

Cat Scratch Disease: 9 Years of Experience at a Pediatric Center.

BackgroundA more complete understanding of the epidemiology, risk factors, and clinical features of cat scratch disease (CSD) in children could help guide patient care.MethodsWe conducted a retrospective analysis of children presenting to a tertiary pediatric hospital system in Atlanta, Georgia between January 1, 2010 and December 31, 2018 who had serology, polymerase chain reaction, and/or cytopathological results consistent with a Bartonella henselae infection. We also retrospectively reviewed veterinary diagnostic results performed at the University of Georgia from 2018 to 2020 to ascertain the burden of bartonellosis in companion animals within the state.ResultsWe identified 304 children with CSD over 9 years with the largest proportion of diagnoses made during August (41 of 304, 13.5%) and September (47 of 304, 15.5%). The median age of child cases was 8.1 years (interquartile range [IQR], 5.4–12.1); 156 (51.3%) were female; 242 of 262 (92.4%) reported feline exposure; and 55 of 250 (22%) reported canine exposure of those with exposure histories documented in the medical record. Although lymphadenopathy was present on physical examination in the majority of cases (78.8%), atypical presentations lacking lymphadenopathy were also common (63 of 304, 20.7%). Among children with radiographic imaging, 20 of 55 (36.4%) had splenomegaly and 21 of 55 (38.1%) had splenic and/or hepatic microabscesses. Among veterinary data, Bartonella seroprevalence was 12 of 146 (8.2%), all among canines, with a geographic distribution that spanned the state of Georgia.ConclusionsDistinguishing clinical features of CSD included subacute regional lymphadenopathy in school-aged children in the late summer, almost all of whom had cat exposure. Atypical clinical manifestations of CSD were also commonly identified.

Serological review of Bartonella henselae and Bartonella quintana infection among Malaysian patients with unknown causes of febrile illnesses.

Limited information is available on human exposure to Bartonella infection, i.e., Bartonella henselae (causative agent of cat scratch disease) and Bartonella quintana (causative agent of trench fever) in West Malaysia. This study reports a review of serological findings obtained from patients attending to a teaching hospital in Klang Valley, Malaysia. An indirect immunofluorescence assay (IFA) was used to determine IgG and IgM antibody titers against B. henselae and B. quintana. In a pilot study conducted between 2013-2015, IgG antibodies against Bartonella spp. (either B. quintana and B. henselae) were detected in 14 (36.8%) of 38 patients who were clinically suspected of rickettsial infections, while IgM antibody was detected in 4 (10.5%) patients. This has prompted us to investigate the serologic responses of patients who were clinically suspected of other febrile causes besides rickettsial infection. Of the 59 serum samples analysed in a follow-up investigation, Bartonella IgG antibodies were detected from 7 (11.9%) patients, of which 5 (27.8%) and 2 (18.2%) patients were clinically suspected of rickettsial infection (n=18) and dengue (n=11), respectively. None of the sera obtained from the leptospirosis (n=10), legionellosis (n=10) and mycoplasma infection (n=10) groups were seropositive to Bartonella spp. The review of Bartonella serological findings in this study highlights that Bartonella infection is not uncommon and should be considered as one of the causes for febrile illness in Malaysia.

Choroidal granulomas due to Bartonella henselae infection: A case series

To report a case series of 3 patients with choroidal granulomas due to Bartonella henselae infection in order to raise awareness about this etiology in the differential diagnosis of choroidal granulomas. A retrospective case series of patients with choroidal granulomas due to Bartonella henselae infection who consulted between 2018 and 2020. Data were collected from the medical records (demographics, visual acuity (VA), laboratory tests, treatment, imaging). Patients were a 48-year old man, a 14-year old girl and a 31-year old man. They all had a choroidal granuloma seen on optical coherence tomography (OCT) and angiography. The laboratory work-up revealed a positive serology for Bartonella henselae in all patients. On multimodal imaging choroidal granulomas in B Henselae appeared as single or multiple, uni or bilateral round yellowish lesions. Fluorescein and indocyanine green angiography of the granuloma showed respectively a late staining and a hypofluorescence. On EDI-OCT choroidal granuloma appeared as a round hyporeflective lesion in the choroid with a retinal elevation. The exclusion of other diagnosis, the natural course and the serology must lead the ophthalmologist to evoke the diagnosis.

Serological and Molecular Detection of Bartonella henselae in Cats and Humans From Egypt: Current Status and Zoonotic Implications

Bartonellosis is a vector-borne zoonotic disease caused by the intracellular bacterium of genus Bartonella. The disease has a worldwide distribution and cats represent the major reservoir of this disease. Despite its global distribution, very limited previous studies have investigated the occurrence of bartonellosis in cats and their owners in Egypt. In an endeavor to explore this topic, we investigated the occurrence of Bartonella henselae (B. henselae) infection in 225 samples (blood, saliva, and claw) obtained from 75 healthy cats in Upper Egypt. These samples were routinely obtained during veterinary clinic visits. This study also involved an examination of 100 humans, including cat owners and people with a history of contact with cats. Attempted isolation and identification of B. henselae in cats were also performed. Furthermore, PCR was performed for molecular identification of B. henselae in blood samples from cats. Meanwhile, an immunofluorescent assay was performed to study the seroprevalence of B. henselae infection in humans. In this study, B. henselae could not be isolated from any of the examined blood, saliva, or claw samples from cats. Interestingly, B. henselae was identified molecularly in 8% (6/75) of blood samples from cats. The seroprevalence of B. henselae in humans was 46% and its occurrence was higher in females (46.6%) than in males (41.7%) (P = 0.748). B. henselae infection was higher among cat owners [51.4% (19/37)] than among people with a history of contact with cats [42.9% (27/63)] (P = 0.410). Infection was higher in rural regions [79.5% (31/39)] than in urban regions [24.6% (15/61)] (P < 0.001). Collectively, this data provide interesting baseline information about the occurrence of B. henselae in cats and humans in Upper Egypt, which reflects the potential zoonotic transmission of this bacterium. Future study is mandatory to explore the occurrence of B. henselae in major reservoirs in Egypt.

Child Neurology: Bartonella henselae Neuroretinitis in 2 Patients.

Neuroretinitis due to Bartonella henselae infection is a rare cause of vision loss in children. Two pediatric cases of acute unilateral vision loss accompanied by edema of the optic nerve on fundoscopic examination are presented. Severe causes of vision loss were excluded. During the course of the disease, macular stellate exudates emerged on control fundoscopic examinations, and diagnosis of neuroretinitis was made. A causative agent was confirmed by serologic examination, as high titers of IgM and IgG antibodies to Bartonella henselae were detected. Both patients significantly recovered after oral antibiotic treatment.

Serious and Atypical Presentations of Bartonella henselae Infection in Kidney Transplant Recipients.

This article describes 5 cases of bartonellosis with fever and atypical clinical presentations in kidney transplant recipients: thrombotic microangiopathies, recurrent hemophagocytosis, and immune reconstitution syndrome after treatment. The diagnosis, the pathological lesions, and treatments are described. Bartonellosis must be researched in solid organ transplant recipients with fever of undetermined origin.

Osteomyelitis associated with Bartonella henselae infection in a young cat

Osteomyelitis associated with Bartonella henselae infection in a young cat

Seroprevalence of Bartonella henselae and Bartonella quintana Infection and Impact of Related Risk Factors in People from Eastern Slovakia.

The genus Bartonella is a rapidly expanding group of ubiquitous bacteria that occur mainly in different animal species, but some can also be transmitted to humans. Three species, B. henselae, B. bacilliformis, and B. quintana, are responsible for the majority of human cases. The severity of the clinical symptoms often depends on the immune status of the patient, but others factors such as the species of the pathogen, virulence factors, and bacterial load also can play an important role. As the information on the occurrence of bartonellosis in the human population in Slovakia is absent, the aim of our pilot study was to determine the seroprevalence against B. henselae and B. quintana in the population of people living in Eastern Slovakia, and to identify the impact of related risk factors. Of 536 people included in the study, 126 (23.5%) showed positivity for anti-B. henselae antibodies and 133 (24.8%) against B. quintana. A statistically higher prevalence was confirmed only in the case of B. quintana in women regardless of the risk group. In analyzing the risk factors, we found significant differences between B. henselae seropositive and seronegative groups only in uric acid levels and serum creatinine, both, however, clinically irrelevant. Significant, but clinically irrelevant differences were observed also in alanine aminotransferase (ALT) levels and creatinine in people seropositive to B. quintana.

The Continuing Ophthalmic Challenge of Bartonella henselae

PurposeTo better understand the history and epidemiology of Bartonella henselae infections of the eye and adnexa, and their relationship to cat scratch disease (CSD). We also assess B. henselae infection as a public health threat.MethodsWe reviewed the available literature concerning B. henselae infections of the eye and CSD, and attempted calculation of the incidence and prevalence of both B. henselae eye infections and CSD from the database of the Rochester Epidemiology Project.ResultsIt took nearly a century of determined effort to reveal that Henri Parinaud’s oculoglandular syndrome (POGS) (1889) and Leber’s stellate retinitis (1916) were the result of B. henselae infection and are subtypes of CSD. These ocular infections remain of clinical, epidemiologic, and public health concern to ophthalmologists with many unanswered questions. Their incidence and prevalence have yet to be accurately determined. Our attempt to achieve this through the Rochester Epidemiology Project database suggests a major obstacle is inconsistent with nonunanimous diagnostic terminology and coding.ConclusionsModern serologic testing and molecular diagnostic techniques offer ophthalmologists the opportunity to make B. henselae infection of the eyes an area of “precision medicine.” For this to happen, greater awareness and teaching about this disease, updated terminology, and a greater clinical and research effort are required.