Social history was pertinent for the patient traveling to Mexico from 11/15-4/16 where he consumed unpasteurized cheese. Brucella IgG was positive and IgM negative suggesting the infection had been present for some time. Treatment with doxycycline, rifampin, and gentamicin was begun and a TEE was ordered which demonstrated markedly worsened aortic insufficiency (AI) compared with TTE 4/16, bicuspid valve, mild aortic stenosis, pseudoaneurysm with leaflet perforation, graft dehiscence and possible paravalvular abscess. Suspected infective endocarditis (IE) was confirmed and his antibiotic regimen was expanded to doxycycline, rifampin, gentamicin, and trimethoprim/sulfamethoxazole. The patient was transferred for cardiothoracic surgery to replace the infected valve and graft. Post-operatively, the patient had multiple complications and expired approximately 1 month post-op.
Discussion: Brucellosis is caused by Gram negative, non-spore forming, intracellular coccobacilli. The organism infects the reproductive organs of animals and is shed into their body fluids. The most common mode of transmission is eating unpasteurized milk products from infected animals. Mode of transfer via inhalation of aerosols most often affects laboratory technicians or farm workers.
Mortality rates for brucellosis are usually between 1-5% and endocarditis accounts for more than 80% of these deaths. Endocarditis is an uncommon presentation of Brucella infections, which can present immediately or many years after onset of symptoms. Underlying valvular damage is present in about half of the cases and the aortic valve is most commonly involved. Symptoms are usually present for about 3 months prior to definitive diagnosis. As internists, we see patients with CHF and COPD exacerbations almost every day. Since these patients present with the same pattern of symptoms, it is imperative that a complete history is obtained on every patient and the differential diagnosis is broad and complete. Most likely the patient had infection of the graft and IE causing the third degree heart block 1 month prior to the presentation with fever, severe AI and positive blood cultures. No blood cultures were done on that admission. Had the diagnosis been made then, would the outcome have been different?
Conclusions: Brucellosis is a rare infection and Brucella endocarditis even more rare. As noted by our case, it is a disease that can have devastating results if not diagnosed and treated in a timely manner. It is important for hospitalists and other primary care providers, especially those practicing in highly diverse cities with travel to endemic areas, to take a complete history and consider uncommon causes of common disease processes.