Case Report
Infective endocarditis (IE) is a potentially fatal systemic infection. It is a serious public health concern due to its high rate of morbidity and mortality.
One of the main causes of the rise in the population at risk for IE is antibiotic resistance. Furthermore, the development of new diagnostic instruments and multimodal imaging for IE diagnosis is a major contributor to the rise in IE incidence.
A variety of criteria are usually necessary to put this population at risk, such as the presence of predisposing risk factors, especially for those who have prosthetic valves, congenital heart disease, or any intracardiac debris. The modified Duke criteria are used to establish the diagnosis of IE.
Blood culture is crucial for diagnosing and treating endocarditis, accounting for 5-10% of cases. BCNIE is often severe and difficult to diagnose, with three main categories: fastidious microorganisms, bacterial endocarditis, and true BCNIE due to uncultured intracellular bacteria.
Brucella species, Coxiella burnetii, Bartonella species, Legionella species, Mycoplasma species, and Tropheryma whipplei are the primary causes of BCNIE.
Few cases of Bartonella henselae endocarditis have been documented in the literature, making it a rare yet dangerous illness. Due to its rarity, diagnosis is difficult and frequently causes delays and problems. Diagnosing Bartonella endocarditis is made more difficult by its unusual presentation, especially in groups with no shared risk factors.
This report’s objective was to describe a case of B. henselae endocarditis linked to domestic animals in Tunisia that were infected with Bartonella, emphasizing the difficulties in diagnosing and treating the condition.
Case Presentation
In July 2023, a 65-year-old Tunisian woman arrived at a department with arthralgia, weight loss, symmetrical petechial and purpuric rashes on her feet, and general weakness. The patient stated that they had had a fever for two months. For the previous five years, she had type 2 diabetes, which was successfully treated. Additionally, the patient was taking levothyroxine and had hypothyroidism. She had dyslipidemia as well. The patient had coronary stenting in 2021 due to a myocardial infarction that was not ST-elevation.
Investigations:
Echocardiography showed no valvular heart disease and a preserved left ventricular ejection fraction. A gastroenterologist also evaluated the patient for anicteric cholestasis and thrombocytopenia three months prior to the current admission. Additionally noted were clinical signs of portal hypertension, including splenomegaly and mild ascites. The findings of the hepatitis B and hepatitis C serological testing were negative. The diagnosis was confirmed by the abdominal ultrasound results, which showed features consistent with portal hypertension and cirrhosis categorized as stage F3–F4 based on FibroScan analysis. The patient’s body temperature was 38.1 °C when they were admitted.
In the lower limbs, vascular ecchymotic purpura were noted. There were no abnormalities found during the cardiovascular examination, and splenomegaly was palpable. An echocardiogram showed no anomalies in wall motion and a maintained left ventricular ejection fraction. A tricuspid aortic valve with a 4 mm x 9 mm mobile image on the non-coronary cusp prolapsing into the left ventricular outflow tract resulted in grade 2 aortic insufficiency and a 4 mm vena contracta. Figure1
The patient’s initial biochemical profile showed anemia. Liver function tests showed modest abnormalities, inflammatory marker levels were raised, and the immunological profile showed no anti-extractable nuclear antigens (ENA), anti-neutrophil cytoplasmic antibodies (ANCA), or anti-mitochondrial antibodies (anti-ML). Anti-cyclic citrullinated peptide (anti-CCP) and anti-fibrillarin antibodies (anti-FI) were both negative, but the rheumatoid factor (RF) level was high, surpassing 200 IU/mL.
Medium-intensity C3 and IgM deposits were found in the vascular structures, which is a sign of leukocytoclastic vasculitis, according to a skin biopsy. Empirical antibiotic therapy was started in the presence of infective endocarditis symptoms, even though blood cultures were negative and a thoracoabdominopelvic computed tomography (CT) scan revealed no abnormalities.
Treatment
The treatment regimen of ampicillin, oxacillin, and gentamicin initially improved apyrexia and inflammatory markers after 10 days. However, febrile episodes recurred and C-reactive protein levels increased, indicating incomplete response. Serological tests for culture-negative endocarditis showed negative results.
However Serological testing for Bartonella henselae revealed positive IgM and IgG levels. Antibiotic treatment with rifampin and doxycycline was started.
A patient recalled being cat scratched prior to her admission. She showed significant improvement with treatment, resolving fever, normalizing inflammatory markers, and restoring liver function. However, a month later, acute pulmonary edema appeared, and coronary angiography revealed triple-vessel disease with left main coronary artery involvement. Echocardiography revealed vegetation responsible for grade 2 aortic valve regurgitation.
A patient underwent aortic valve replacement using a mechanical prosthesis and coronary artery bypass grafting. Postoperatively, the valve culture showed positive Bartonella henselae, supporting the diagnosis. The patient showed a favorable clinical course, remaining apyretic with a preserved general condition. After a year, she continues to undergo regular follow-ups, maintaining stable recovery and no signs of complications
