A case of Brucella melitensis endocarditis in a patient with cardiovascular implantable electronic device

BACKGROUND: Brucellosis is a bacterial infection, caused by the nonmotile gram-negative aerobic coccobacilli. The clinical manifestation of brucellosis is variable, ranging from mild disease to severe disease. The gold standard test to confirm the diagnosis of brucellosis is assaying blood, bone marrow, or other body fluids or by tissue culture. Preferred first-line treatment in adults with uncomplicated, nonlocalized disease consists of doxycycline–aminoglycoside combination. The recommended duration of treatment is 6 weeks. Cardiovascular implantable electronic device (CIED) infection caused by brucellosis is rare and has been reported in a few case study series. We report a case of Brucella melitensis infection of CIED where, contrary to most authorities recommending removal of device, because of the patient’s multiple comorbid conditions and age, an attempt was made to keep the device and place the patient on lifelong prophylaxis treatment. CASE REPORT: A 70-year-old Kuwaiti male, with a background history of Type 2 diabetes mellitus, atrial fibrillation, hypertension, and sick sinus syndrome with a pacemaker fixed 1 year prior to his presentation, was diagnosed as having brucellosis. He was initially started on rifampicin and doxycycline. A transesophageal echo showed no evidence of vegetations seen at aortic valve or mitral valve. The two pacing leads, one in right atrium appendage and the other in right valve apex, looked smooth and clean with no clear adherence. Cotrimoxazole and gentamicin were added, per the 2015 European Society of Cardiology Guidelines for the management of infective endocarditis. The plan was to treat the patient with an aminoglycoside for the first 3 weeks, and then de-escalate to three drugs. The patient’s fever subsided for several days following treatment, and subsequent blood cultures showed sterilization of bloodstream. He developed an acute kidney injury from aminoglycosides, which required 2 months of inpatient dialysis treatment. He was later discharged after completing a total of 3 months of antibiotic treatment. At the time of discharge, the patient’s Brucella titer was <1:160. The patient was discharged with a 2-month supply of rifampin and doxycycline. CONCLUSION: In all published studies on Brucella infective endocarditis with a cardiovascular implantable device, the recommendation was for device removal and extended treatment with doxycycline combined with rifampin and/or trimethoprim–sulfamethoxazole, plus parenteral aminoglycosides for the first 3 weeks. There have been two cases in the literature that have studied CIED infected with brucellosis where an attempt was made to retain the device. In both cases, relapse occurred upon discontinuation of treatment. It is not clear whether lifelong antibiotic suppression treatment would prevent relapse.