Patient 4. A 68-year-old man presented with (R) knee swelling and back pain for 4 months. He was initially diagnosed as OA and spondylitis. He is known to have DM, HTN, and IHD with a permanent pacemaker. CT scan showed degenerative spinal canal stenosis at L4-L5 with mild degree of bilateral SI joints degeneration. He had received epidural injection of steroid and (R) knee injection with temporary improvement. There was no history of fever or contact with TB patients; however, there was strong history of animal contact. He received one month of antibiotics prior to presentation but without improvement. General examination was normal but the (R) knee was swollen, tender, and with decreased ROM (10-15). CT scan showed moderate to large effusion of the (R) knee with associated synovial thickening and OA changes (Figure 4). The WBC was normal, ESR 70 mm/hr., and CRP 47 mg/mL, and rheumatoid factor was negative. The blood urea and creatinine was raised at 16.8 mmol/L and 140 mumol/L. Synovial fluid cultures were positive for Brucella species but the blood culture was negative. Blood serology for brucella was 1 : 10240. He received 3/12 of doxycycline rifampicin with full functional recovery.