Cat Scratch Research Articles

Neuroretinitis: a comprehensive review on aetiologies, clinical manifestations, and treatment options.

Neuroretinitis connotes a descriptive clinical entity of optic disc oedema in association with macular exudates in a star configuration. Accordingly, it does not indicate a specific aetiology, although cat scratch disease caused by Bartonella henselae is the most common cause. Historically, the recognition of neuroretinitis dates to the early 20th century with the eventual understanding that the optic disc is the primary target of disease with secondary macular involvement. Neuroretinitis can be broadly divided into four categories: infectious, inflammatory, autoimmune and mimickers. The intention of this article is to review the various aetiologies of neuroretinitis with a focus on the etiopathogenesis, clinical manifestations, and management of B. henselae associated neuroretinitis and recurrent idiopathic neuroretinitis.

Clinical Presentation of Cat Scratch Disease in Pediatric Patients-A Single-Center Study.

Cat scratch disease (CSD) is the infectious disease caused by Bartonella henselae. Its typical presentation is regional lymphadenopathy. Also it may present with symptoms related to involved organs or disseminated disease with fever of unknown origin (FUO). Here children with CSD are evaluated to increase awareness about disease. A total of 29 children diagnosed with CSD between 2019 and 2022 were involved in the study. Patients' demographic characteristics, clinical, laboratory and radiological findings, treatments, and outcomes were analyzed. Seventeen of the patients were male, 12 were female, and their mean age was 116.5 ± 51 months. About 69.6% of them had a history of cat contact. Twenty-seven patient (93.1%) had lymphadenopathy, mostly axillary involved (61.5%). Other manifestations were disseminated disease presented with FUO, neuroretinitis, and encephalopathy. Twenty-seven patients (93.1%) had received antibiotics before admission without any improvement. Ultrasound showed that the affected lymph nodes were conglomerated, lobulated contoured, and cortical thickened, with one-third having cystic suppurative components. Serologic tests were positive in 24 of 27 patients. Twenty-one patients gave response to 5 days azithromycin treatment, in 8 patients this treatment extended to 10-14 days, rifampicin with/without doxycycline was given to 6 patients, and steroids were given to 3 patients. In case of regional lymphadenopathy, especially axillary, not responding to nonspecific antibiotics CSD should be suspected. Cat contact history and serological and ultrasonographic findings are useful for diagnosis. Even if CSD responds well to azithromycin, sometimes prolongation of azithromycin and addition of other antibiotic or steroid may be required.

Bilateral Idiopathic Neuroretinitis.

Neuroretinitis (NR) is a rare inflammatory condition characterized by sudden vision loss, optic disc edema and macular star appearance predominantly affecting individuals in their third and fourth decades of life. This paper describes the case of 33-year-old Caucasian man with no significant medical history complaining of decreased vision for about a week. The ophthalmological exam revealed best-corrected visual acuity (BCVA) for the right eye (RE) of 0.8 (decimal notation) and of 0.9 for the left eye (LE). Intraocular pressure (IOP) was 20 mmHg in RE and 18 mmHg in LE. Slit-lamp examination of both eyes (OU) showed no evidence of intraocular inflammation in the anterior chamber or vitreous cavity. Examination of the posterior pole of the right eye showed bilateral papilledema with an incomplete macular fan pattern. Despite extensive laboratory tests, including serologic and imaging investigations, a definitive etiology remained unclear. It is very important to differentiate NR from other optic nerve disorders, requiring careful clinical evaluation and observation of the evolution of symptoms.

The strange cat scratch colon signs in a patient with multiple colon tumors.

The strange cat scratch colon signs in a patient with multiple colon tumors.

Suppurative Granulomatous Osteomyelitis with Microcystic Changes Due to Mycobacterium chelonae- abscessus Complex

Abstract Introduction/Objective Mycobacterium chelonae and Mycobacterium abscessus are rapidly growing non-tuberculous mycobacterium found in soil and water, and represent rare causes of skin and soft tissue infection. Treatment typically involves an extended course of antimicrobial therapy and occasionally surgical debridement. Previous reports have described a distinctive pattern of suppurative granulomatous inflammation with microcystic changes in skin biopsies; however, the morphologic changes of M. chelonae-abscessus complex as a cause of osteomyelitis have not been well-documented in the literature. Methods/Case Report We searched our database from 2013 to 2024 for bone samples diagnosed as granulomatous inflammation in which M. chelonae or M. abscessus were identified on concurrent microbiology studies. Patient demographics, risk factors for infection, and treatment data were collected. Results (if a Case Study enter NA) Three patients with culture- or PCR-confirmed M. chelonae (2) or M. abscessus (1) were identified. All infections involved bones of the distal extremities. Patients were 57 years and older with risk factors for infection that included: diabetes (1), intravenous drug use (1), and long-term immunosuppressive therapy (1). All patients presented with osteomyelitis refractory to antibiotic therapy for which bone biopsy, bone resection, or amputation was performed. All cases showed suppurative granulomatous inflammation with microcystic changes. Cystic spaces were markedly enriched for acid-fast bacilli on Fite and/or Ziehl-Neelsen stains. In two patients, the antimicrobial regimen was changed as a result of the pathologic findings and microbiologic testing that provided additional information about speciation and susceptibilities. Conclusion Suppurative granulomatous inflammation has a broad differential that includes blastomycosis, sporotrichosis, cat scratch disease, non-tuberculous mycobacterial infection, and granulomatosis with polyangiitis, for which there are substantial treatment differences. When this pattern of microcystic suppurative granulomatous inflammation is encountered, it is important to perform special stains for acid-fast bacilli, particularly when seen in distal extremity lesions from patients with infections that are refractory to empiric antibiotic therapy.

Macular Star and Neuroretinitis with Optic Disk Edema

Neuroretinitis is an inflammatory disorder of the eye presenting with unilateral visual loss, optic disc edema, and subsequent formation of a macular star. Neuroretinitis can be classified as idiopathic, infectious and recurrent. Following a detailed patient history, essential work-up should include Bartonella antibody titers, the rapid plasma reagin (RPR) test, the tuberculin skin test, ACE and lysozyme levels, and a two-view chest X-ray. Among infectious etiologies of neuroretinitis, cat scratch disease caused by Bartonella henselae is the most frequently observed, accounting for two-thirds of cases. Recurrent neuroretinitis is characterized by poorer visual recovery and visual field loss. Patients should be informed about the possibility of recurrence to prevent severe vision loss.

7245 A case of refractory methimazole-induced agranulocytosis treated with high-dose G-CSF

Abstract Disclosure: S. Shah: None. D. Mathur: None. G. Bao: None. S. Shah: None. D.M. Antoniucci: None. Case Presentation: Despite their efficacy in treating hyperthyroidism, antithyroid drugs (ATDs) carry a rare risk of life-threatening agranulocytosis (ANC <500/μL), with incidence varying from 0.1 to 0.4%. Patients with agranulocytosis may benefit from granulocyte-colony stimulating factor (G-CSF) to shorten recovery and reduce hospitalization costs. We present the case of a 37-year-old woman with Graves disease, who developed methimazole (MMZ)-induced agranulocytosis and was treated with high-dose G-CSF. At diagnosis, MMZ 10 mg BID was started and later reduced to 5 mg BID. After 2 months, she presented to the ED with a dental infection, an arm abscess after a cat scratch, and fevers. Blood-work showed WBC of 1500/μL, ANC of 0/μL, and rare granulocytes on manual differential. Flow cytometry did not show clonal lymphoid or blast populations. MMZ was stopped and antibiotics were started. Her hyperthyroidism was managed with propranolol and iodine solution in anticipation of definitive thyroidectomy. On day 4 of admission, tbo-filgrastim 450 mcg daily injections were started for persistent neutropenia. Despite 3 doses of G-CSF, ANC remained at 0/μL, prompting a bone marrow biopsy that showed no dysplastic or aplastic phenotype. After 9 doses of G-CSF up to 600 mcg daily, ANC fully recovered on day 14. She underwent thyroidectomy, and 2 months later her ANC and thyroid hormone levels were within normal. Discussion: This report illustrates a case of severe, refractory ATD-induced agranulocytosis and highlights the utility of G-CSF in treating high risk patients. Classically, ATD-induced agranulocytosis occurs in those aged >65 years, follows high dose therapy, and occurs within 60 days of treatment initiation. G-CSF is often used in clinical practice, although its efficacy is not well established. A recent meta-analysis demonstrated that G-CSF can hasten recovery by 3 days. Other studies report no difference or prolonged agranulocytosis up to 14 days despite G-CSF, especially in patients with ANC <100/μL. Whether this is a lack of true benefit or inadequate dosing is unclear. This case reviews the use of high dose G-CSF in a patient with profound neutropenia. Prompt ANC recovery was crucial given neutropenic fevers and need for thyroidectomy. Even with escalating doses of G-CSF, her ANC required 14 days to recover - twice the typical length of recovery. Whether G-CSF impacted the time course of her recovery is difficult to discern. Identifying the mechanisms underlying ATD induced agranulocytosis may explain delayed responses to G-CSF. Notably, the 2016 ATA guidelines do not incorporate G-CSF into ATD-induced agranulocytosis management. This conservative approach reflects a paucity of evidence supporting G-CSF use. Further research must investigate underlying mechanisms and clarify indications for G-CSF use to improve outcomes and reduce costs of care. Presentation: 6/1/2024

Cat scratch colon and cecal barotrauma perforation during colonoscopy with CO2 insufflation.

Cecal perforation from barotrauma is a rare complication of colonoscopy, even with the use of CO₂ insufflation, which is generally preferred over room air due to its rapid absorption and reduced patient discomfort. A 64-year-old woman with hypertension and dyslipidemia underwent a routine colonoscopy with CO₂ insufflation. Multiple diverticula were noted, and upon reaching the cecum, several parallel linear lesions with spontaneous bleeding, consistent with "cat scratch" colon, were observed. Hemostasis was achieved with 10 endoscopic clips. A subsequent CT scan revealed pneumoperitoneum and the clips in the cecum. The patient was managed conservatively with bowel rest and intravenous antibiotics, showing a favorable clinical course and was discharged on the fifth day. This case highlights the potential for cecal perforation due to barotrauma even with CO₂ insufflation during colonoscopy, emphasizing the need for awareness and prompt management of such complications.

Lymph Node Histology and Metagenomic Sequencing in a child with Cat Scratch Disease.

A 4-year-old boy presented with fever and lymphadenopathy. Despite antibiotic treatment for suspected lymphadenitis, there was minimal improvement. A lymph node biopsy revealed granulomas, raising suspicion of cat scratch disease (CSD). The boy had been scratched by a kitten a month prior. Metagenomic testing of the tissue confirmed the presence of Bartonella henselae, the causative agent of CSD. It is important to incorporate molecular diagnostic tools into clinical practice for precise and timely diagnosis of infectious diseases.

Detection of Bartonella henselae in feline erythrocytes in Egypt by using Giemsa staining, transmission electron microscopy, and polymerase chain reaction.

Bartonella species (Bartonella spp.) have gained recognition as a significant human pathogen, implicated in a wide range of diseases. Among these, Bartonella henselae infection has been extensively studied for its primary occurrence in cats and its role in the development of cat-scratch disease in humans. While light microscopy and transmission electron microscopy (TEM) have traditionally played crucial roles in identifying causative agents of infectious diseases, including Bartonella spp., the accuracy of these methods in identifying Bartonella spp. remains undefined. Therefore, this study aims to bridge this gap by employing both light microscopy and TEM to detect Bartonella in feline blood samples and to confirm B. henselae with polymerase chain reaction (PCR). Examination of blood smears stained with Giemsa and toluidine blue semithin sections by using light microscopy revealed the presence of intraerythrocytic corpuscles, suggesting Bartonella infection in six out of 33 examined cat blood samples. TEM findings corroborated these observations, showcasing the engulfment of bacteria by the erythrocyte membrane, along with the presence of some Bartonella spp., adhering to the erythrocyte wall. PCR-based molecular detection confirmed the presence of B. henselae in these six samples. It is concluded that light microscopy and TEM are considered valuable in the screening of cats' blood for the potential presence of Bartonella. However, further molecular techniques are essential for precise identification and confirmation of specific Bartonella spp. RESEARCH HIGHLIGHTS: Giemsa-stained blood smear and semithin section showed potential intraerythrocytic Bartonella spp. corpuscles. TEM demonstrated the engulfment of Bartonella spp. by the erythrocyte membrane, along with the presence of some Bartonella spp. adhering to the erythrocyte wall. Molecular analysis of blood samples from cats by PCR unveiled that six out of 33 (18.18%) samples tested positive for B. henselae infection.

Tanto va la gatta al lardo che ci lascia lo zampino

The case describes a seven-year-old boy with a painful swelling in the right armpit. After excluding a neoplastic condition and noting recent contact with cats, Cat Scratch Disease was diagnosed, confirmed by positive serology for Bartonella henselae. Treatment with azithromycin led to improvement.

Cat Scratch Disease in Pediatrics: Who Has Systemic Involvement?

Bartonella henselae is the agent responsible for cat scratch disease (CSD). Although lymphadenopathy is typically the defining symptom, some patients develop potentially severe systemic compromise. It is unknown why some patients progress to systemic disease. The objective of this study was to describe the clinical, epidemiologic and laboratory characteristics of children with CSD and to analyze the differences between systemic versus localized infections. Patients were identified by a retrospective review of medical records at a tertiary pediatric care hospital in Buenos Aires, Argentina, from January 2012 to July 2021. A CSD case was defined as any patient who presented compatible clinical findings with a positive serologic test (IgG >1/64 or IgM immunofluorescence) for B. henselae. A total of 197 patients were identified, with a median age of 8 years (range: 1-17.4 years). The most frequent clinical symptoms were fever and lymphadenopathy. Systemic involvement was present in 34.5% (n = 68) of patients and the most common presentation was splenic abscess (n = 51), followed by liver abscess (n = 23), chorioretinitis (n = 9), osteomyelitis (n = 5) and pneumonitis (n = 3). Patients with invasive disease more frequently presented with fever (79.4% vs. 50.3%) (P<0.001) and had higher C-reactive protein levels (24.9 vs. 6.7 mg/L) (P<0.001). Antibiotic therapy was administered to 95.9% (n = 187) of patients and most with systemic disease (77%) used combination treatment. Most patients recovered fully, and there were no reported deaths. CSD must be considered a potential cause of lymphadenopathy. Patients with fever and elevated C-reactive protein should be evaluated to rule out systemic compromise.

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.

Pneumonia With Empyema: A Rare Clinical Presentation of Bartonella henselae Infection in a 10-Year-Old Boy.

Cat-scratch disease is a common zoonosis in children. However, atypical clinical presentation of cat-scratch disease is less common, and lung involvement is particularly rare. The usual presentation of lung disease in bartonellosis includes other organ involvement and is more common in immunocompromised patients. We present a 10-year-old immunocompetent patient with pneumonia and inoculated empyema caused by Bartonella henselae, without any other organ involvement, which occurred 2 weeks after lymphadenopathy. The definite diagnosis was established using the polymerase chain reaction of the empyema obtained from thoracocentesis. The boy was treated with several antibiotics (ceftriaxone, azithromycin, amoxicillin with clavulanic acid, meropenem and vancomycin) and completely recovered after the 3-month follow-up period. This is a unique case of the difficult-to-treat pneumonia with inoculated empyema, caused by B. henselae, in an immunocompetent child, without any other organ involvement. The clinical course was favorable. A high level of clinical suspicion is mandatory for the diagnosis.

An overview of bacillus anthracis bacteria, one of the most important biological agents

&lt;p&gt;So far, more than 1400 human pathogens have been identified. Of this number, more than 60% have a common origin between humans and animals, which infect humans through animal reservoirs. These diseases include viruses such as influenza, less common (but fatal) diseases such as rabies, and neglected parasites such as &lt;em&gt;echinococcosis&lt;/em&gt; and &lt;em&gt;cysticercosis&lt;/em&gt;. The subcategory of bacterial zoonoses also varies, with pathogens common in industrial settings (including &lt;em&gt;salmonella&lt;/em&gt; and &lt;em&gt;bartonella henselae&lt;/em&gt;, the causative agent of cat-scratch disease) and diseases more associated with impoverished tropical regions (such as melioidosis and leptospirosis). In this article, we will examine the &lt;em&gt;bacillus anthracis&lt;/em&gt; bacteria that causes anthrax, which is one of the most important bacteria (the cause of zoonotic diseases) and is also considered one of the agents of bioterrorism.&lt;strong&gt;&lt;/strong&gt;&lt;/p&gt;

On-host flea phenology and flea-borne pathogen surveillance among mammalian wildlife of the pineywoods of East Texas.

Flea-borne diseases are endemic in Texas, U.S.A., with an increasing incidence of flea-borne typhus and cat scratch disease. Knowledge of flea natural history could provide information to protect public health, yet many knowledge gaps remain outside of plague-endemic regions. Our objective was to characterize seasonal activity patterns of fleas on common mammalian wildlife species and test fleas and wildlife for Rickettsia and Bartonella pathogens. We performed one year of monthly trapping for rodents and medium-sized mammals in a national forest with high recreational use and urban encroachment in East Texas. From 90 mammal captures representing seven species, 101 fleas were collected representing Polygenis spp., Ctenocephalides felis, and Orchopeas species. Virginia opossums (Didelphis virginianus) hosted 99% of the collected fleas (100 fleas) and a single flea was on an eastern woodrat (Neotoma floridana). Flea infestation prevalence of opossums was 79% (23/29). Mean flea abundance was 4.39 fleas, with intensity peaking in spring. One cat flea removed from an opossum was positive for Bartonella henselae. Furthermore, we identified tissue or blood of four raccoons (Procyon lotor) and one golden mouse (Ochrotomys nuttalli) positive for Rickettsia amblyommatis. These findings provide an ecological basis for the maintenance of vectors and pathogens from sylvatic settings.

Evaluating undesired scratching in domestic cats: a multifactorial approach to understand risk factors.

Despite being a natural feline behavior, scratching can become undesirable from a human perspective when directed at household items. This complex behavior can stem from various motivations, ranging from individual cat characteristics to environmental factors. This study investigates the factors influencing the increased level of undesirable scratching behavior in domestic cats, considering both cat-related and environmental aspects. Data from 1,211 cats were collected for this study. An online questionnaire comprising three sections was utilized. The first section gathered caregiver demographics, while the subsequent section examined aspects of cats' daily routines, social interactions, environments, behaviours, and temperaments. The final section assessed the frequency and intensity of undesirable scratching behavior in cats. Scratching behavior was evaluated based on a combined scratching index. The study suggests that the presence of a child may be associated with scratching episodes in the home environment. Additionally, factors such as play duration, playfulness, and nocturnal activity were identified as significant contributors to heightened scratching levels (p ≤ 0.05). Aggressiveness and disruptiveness also played significant roles in increased scratching behavior (p ≤ 0.05). The location of scratching posts emerged as a significant factor, with posts placed in areas frequented by the cat being more effective in redirecting scratching behavior (p ≤ 0.05). This study reveals several significant associations between cat characteristics, nocturnal activity and play, as well as the environment. It underscores the multifaceted nature of undesirable scratching behavior and emphasizes the importance of comprehensively understanding both the individual characteristics of the cat and its environment to effectively address this behavior.

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.

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

IntroductionThe 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. MethodsWhole 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. Results14 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. ConclusionsThere 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.