Osteomyelitis in Cat-Scratch Disease: A Never-Ending Dilemma-A Case Report and Literature Review

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.

Vague Presentation of Cat Scratch Disease in a Child

Background: Prolonged fever for more than a week or fever of unknown origin in pediatric patients with or without soft tissue infection should raise suspicion for Bartonella henselae infection. Case Report: A 10-year-old female presented to urgent care with a "bug bite" on the left ring finger, cough, and 2 to 3 days of low-grade fever. Ten days later, her symptoms progressed to soft tissue swelling of the left elbow without fracture on radiograph. Magnetic resonance imaging revealed multiple reniform masses with avid contrast enhancement consistent with suppurative adenitis. She was admitted for irrigation and debridement. The patient underwent surgical debridement with removal of infected lymph nodes. Histology revealed necrotizing granulomatous lymphadenitis. Polymerase chain reaction was positive for B henselae. Antibody titer revealed B henselae immunoglobulin G titer of 1:512 (reference, 1:64), and negative immunoglobulin M titers were indicative of mature immune response. The patient was treated with azithromycin 250 mg tablets twice daily for 3 days followed by 3 days of the 250 mg tablet once daily. Follow-up showed resolution of infection without symptoms concerning for visceral organ infection. Conclusion: While the patient's initial presentation was vague, a complete history, quick follow-up, and decisive intervention prevented significant sequelae such as visceral organ involvement.

Cerebral venous sinus thrombosis and skull base osteomyelitis as manifestations of cat-scratch disease in a pediatric patient: A case report and literature review

Cat-scratch disease (CSD) is caused by Bartonella henselae and usually presents with regional lymphadenopathy. Skull base osteomyelitis and cerebral venous sinus thrombosis are rarely reported, particularly in immunocompetent children. CSD should be considered in the differential diagnosis of any patient with persistent headaches in the setting of cat exposure.

Metagenomic next-generation sequencing may assist diagnosis of cat-scratch disease

Bartonella henselae, the pathogen that causes cat-scratch disease (CSD), is relatively rare in the clinic. CSD usually causes mild clinical manifestations, which self-heal in a matter of weeks. However, in immunocompromised patients, CSD may cause systemic disorders that can lead to critical illness. Due to the diversity of symptom signs and the lack of a golden standard for diagnosis, identifying atypical CSD in a timely manner presents a challenge. Metagenomic next-generation sequencing (mNGS), is a promising technology that has been widely used in the detection of pathogens in clinical infectious diseases in recent years. mNGS can detect multiple pathogens quickly and accurately from any given source. Here, we present a case of atypical CSD, which was diagnosed using mNGS. The patient manifested a fever of unknown infectious origin, and routine antibiotic treatment was ineffective. mNGS was employed to test the patient’s peripheral blood, which led to the detection of B. henselae. This was rarely seen in previous CSD reports. We surmised that the patient presented with atypical CSD and thus a targeted therapy was recommended. Crucially, the patient recovered rapidly. Based on this case study findings, we recommend that CSD should be included in the differential diagnosis for fever of unknown origin and that mNGS may be helpful in the diagnosis of CSD.

The Diagnosis and Management of Pediatric Spine Infections

The management of pediatric spine infections requires a multidisciplinary approach that includes orthopedic surgeons, infectious disease specialists, interventional radiologists, and others. The prevalence of the disease has increased in frequency, virulence, and degree of soft tissue involvement over the past several years; there has also been a resurgence of some types of infections, such as tuberculosis, fungal, and viral pathogens. The diagnosis can often be reached with a detailed history, physical examination, laboratory tests, and imaging studies. Pathologies mimicking infection require a more invasive approach for diagnosis, including core or open biopsy. The treatment of discitis, spondylodiscitis, vertebral osteomyelitis, spinal epidural, and intramedullary abscesses in children is at times complex, and although many infections can be treated non-surgically with antibiotic therapy, some more extensive infections require surgical management. A timely diagnosis is important as it allows the initiation of the appropriate antimicrobial therapy and would decrease the complexity of the subsequent surgical intervention.

Bartonella henselae Persistence within Mesenchymal Stromal Cells Enhances Endothelial Cell Activation and Infectibility That Amplifies the Angiogenic Process

Some bacterial pathogens can manipulate the angiogenic response, suppressing or inducing it for their own ends. In humans, Bartonella henselae is associated with cat-scratch disease and vasculoproliferative disorders such as bacillary angiomatosis and bacillary peliosis. Although endothelial cells (ECs) support the pathogenesis of B. henselae, the mechanisms by which B. henselae induces EC activation are not completely clear, as well as the possible contributions of other cells recruited at the site of infection. Mesenchymal stromal cells (MSCs) are endowed with angiogenic potential and play a dual role in infections, exerting antimicrobial properties but also acting as a shelter for pathogens. Here, we delved into the role of MSCs as a reservoir of B. henselae and modulator of EC functions. B. henselae readily infected MSCs and survived in perinuclearly bound vacuoles for up to 8 days. Infection enhanced MSC proliferation and the expression of epidermal growth factor receptor (EGFR), Toll-like receptor 2 (TLR2), and nucleotide-binding oligomerization domain-containing protein 1 (NOD1), proteins that are involved in bacterial internalization and cytokine production. Secretome analysis revealed that infected MSCs secreted higher levels of the proangiogenic factors vascular endothelial growth factor (VEGF), fibroblast growth factor 7 (FGF-7), matrix metallopeptidase 9 (MMP-9), placental growth factor (PIGF), serpin E1, thrombospondin 1 (TSP-1), urokinase-type plasminogen activator (uPA), interleukin 6 (IL-6), platelet-derived growth factor D (PDGF-D), chemokine ligand 5 (CCL5), and C-X-C motif chemokine ligand 8 (CXCL8). Supernatants from B. henselae-infected MSCs increased the susceptibility of ECs to B. henselae infection and enhanced EC proliferation, invasion, and reorganization in tube-like structures. Altogether, these results indicate MSCs as a still underestimated niche for persistent B. henselae infection and reveal MSC-EC cross talk that may contribute to exacerbate bacterium-induced angiogenesis and granuloma formation.

Breitschwerdt E. Suspected Bartonella osteomyelitis in a dog

Bartonella associated osteomyelitis, while described in humans and a cat, has to our knowledge not been described in dogs. Infection with Bartonella spp. should be considered as a potential bacterial cause of osteomyelitis in dogs.

Costal osteomyelitis due to Bartonella henselae in a 10-year-old girl

Bartonella henselae is the bacterial agent responsible for cat scratch disease. This infection is frequently the cause of localized lymphadenitis in children. It is also sometimes responsible for endocarditis, encephalitis, hepatic peliosis and in rare cases osteomyelitis. We describe the second known case of unifocal thoracic osteomyelitis in a 10-year-old child.

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.

Ecological and Socioeconomic Factors Associated with Bartonella henselae Exposure in Dogs Tested for Vector-Borne Diseases in North Carolina

Bartonella henselae is a zoonotic vector-borne pathogen affecting both humans and dogs. Little is known about the epidemiology of B. henselae in dogs, including risk factors associated with exposure. The objectives of this study were to map the current distribution of B. henselae in dogs in North Carolina (NC) and to identify ecological and socioeconomic factors influencing B. henselae seroreactivity. Results from 4446 B. henselae serology samples from dogs in NC submitted by veterinarians for clinical diagnostic testing to the North Carolina State University College of Veterinary Medicine Vector Borne Disease Diagnostic Laboratory between January 1, 2004 and December 31, 2015 were retrospectively reviewed. These results were used to generate a map of B. henselae seroreactivity. To account for sparsely sampled areas, statistical smoothing using head banging and areal interpolation kriging was performed. Using previously described risk factors for exposure to canine tick-borne diseases, eight multivariable logistic regression models based on biologically plausible hypotheses were tested, and a final model was selected using an Akaike's Information Criterion weighted-average approach. Seroreactivity among dogs tested for vector-borne disease was variable across the state: higher along the southern/eastern coastal plains and eastern Piedmont, and lower in the western mountains. Of 25 explanatory factors considered, the model combining demographic, socioeconomic, climatic, and land use variables fits best. Based on this model, female intact sex and increasing percentage of the county with low-intensity development and evergreen forest were associated with higher seroreactivity. Conversely, moderate development, increasing median household income, and higher temperature range and relative humidity were associated with lower seroreactivity. This model could be improved, however, by including local and host-scale factors that may play a significant role in dogs' exposure.