Recurrent Arthritis Caused by Brucella melitensis in a Chinese Adult: A Case Report

Background: Brucellosis is an endemic systemic infectious disease, the most common complication is bone and joint involvement. Sacroiliac joint infections and spinal joint infections commonly affect adults, but ankle infections are extremely rare. We report a case of recurrent ankle arthritis caused by Brucella melitensis (B. melitensis). Case Presentation: A 50-year-old Chinese male presented to a local hospital with right ankle pain and limited mobility 23 months ago and underwent a synovectomy of the ankle. Specimen culture revealed brucellosis infection in sheep. The patient came to the department of Orthopaedics of our hospital 18 months ago because his symptoms did not improve. The patient's blood culture of bacteria was negative, the serum Rose-Bengal Plate Agglutination Test was positive, and his erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels were significantly elevated. Joint synovial fluid of right ankle was extracted by joint aspiration and sent to the laboratory for real-time polymerase chain reaction (Real-time-PCR) examination, the results showed that there was B. melitensis in the synovial fluid. We concluded that the patient had recurrent Brucella ankle arthritis and was treated with doxycycline (0.1 g po bid), rifampicin (0.6 g po qd) and cefotaxime-sulbactam (2.25 g ivgtt q8h) for six weeks during hospitalization. When the patient was discharged, the symptoms were mostly relieved and the inflammatory indicators returned to normal. At following-up 18 months later, the patient had no discomfort in the right ankle and all inflammatory markers were normal.Conclusion: Brucella ankle arthritis is a rare but serious complication of adult brucellosis. Clinical manifestations and imaging examinations revealed no obvious specificity. In order to prevent ankle deformities, the dead bone of the ankle should be removed and the joint space cleaned and antibiotic therapy should be administered.