A case of mitral stenosis complicated with seronegative Brucella endocarditis

Brucellosis is a multisystemic disease. The most common cause of death from the disease is endocarditis. The aortic valve is most commonly affected. The disease rarely involves the mitral valve. A 30 year-old woman presented with complaints of chills and fever up to 38 degrees C at night, fatigue, palpitations, and dyspnea for the previous 3 weeks. Cardiac auscultation revealed a diastolic murmur in the mitral area. Her temperature was 38.3 degrees C. On echocardiographic examination, the mitral valve area was 0.62 cm (2) and an isoechoic mass thought to be a vegetation was detected on the anterior mitral leaflet. A diagnosis of infective endocarditis was made and vancomycin administration was commenced. Brucella melitensis was isolated in all three blood samples, however, the patient remained seronegative with Brucella agglutination titers of up to 1/160. The antibiotic therapy was then shifted to doxycycline (200 mg/day), rifampicin (600 mg/day), and ciprofloxacin (1000 mg/day). After 30 days of treatment, surgery was performed for the severely stenotic mitral valve and to remove the vegetation. The operation was successful. The postoperative period was uneventful. On the follow-up she had no complaints. In cases with Brucella endocarditis, after diagnosis, antibiotic therapy must be started immediately and when the clinical condition improves, surgical intervention should be performed when indicated.