Chronic Brucellosis Presenting as Cardiac Implantable Electronic Device-Related Endocarditis: Diagnostic Challenges and Management – A Case Report

Background Brucellosis is a zoonotic infection that may rarely involve the cardiovascular system, causing infective endocarditis. Diagnosis of Brucella-associated cardiac implantable electronic device (CIED) endocarditis is challenging because of its indolent course and frequently negative blood cultures. Case Summary A 42-year-old shepherd with an implantable cardioverter-defibrillator had experienced fever, myalgia, arthralgia, and weight loss for approximately 18 months. During this period, investigations for malignancy and rheumatologic diseases were unrevealing. He was subsequently diagnosed with brucellosis at another institution based on a Brucella serum agglutination test positive at a titer of 1:1280, and antibiotic therapy was initiated. Three weeks later, he was referred to our center because of generator pocket erosion and purulent drainage. Tissue cultures from the pocket and repeat blood cultures showed no growth. Transesophageal echocardiography demonstrated a 14 × 8 mm mobile mass attached to the right ventricular lead, suspicious for vegetation. Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) demonstrated increased metabolic uptake around the lead. According to the diagnostic criteria of the 2023 European Society of Cardiology (ESC) Endocarditis Guidelines, Brucella CIED-related endocarditis was diagnosed. Antimicrobial therapy was revised, followed by complete percutaneous device extraction. The patient recovered without recurrence, and device reimplantation was not indicated. Discussion Brucella infection should be considered in patients from endemic regions or high-risk occupational groups presenting with culture-negative CIED infection. In such cases, serological testing combined with transesophageal echocardiography and 18F-FDG PET/CT is essential for diagnosis. Complete device extraction with targeted antimicrobial therapy is crucial, and reimplantation should be individualized.