A 30 year old veterinarian presents with nocturnal pain in the right lower back for 2 weeks, in association with fatigability, night sweats, and fever with chills at night. He migrated from Brazil to the United States 3 weeks ago. He had been working in the same occupation in his home country. His medical history is unremarkable. There is no history of contact with tuberculosis. He has a single stable sexual partner. There is no family history of spondyloarthropathies. His ESR is found to be 20 mm/1h. Radiographs of the pelvis are found to be normal. A tuberculin test was performed in view of the symptoms, but is nonreactive. Prior to migration, he was tested for HIV and found to be negative.
There is a widening of the R/s sacroiliac joint, with enhancement of the fluid within. A high diffuse signal intensity is seen in the bone marrow. The L/s sacroiliac joint appears normal. There is no evidence of erosions or sclerosis. The lumbar spine appears normal.
C. Trachomatis: negative N. Gonorrhoeae: negative
The standard agglutination test yields a brucella immunoglobulin M (IgM) titre of 1:320
Gram stain of the aspirate reveals the presence of numerous gram negative coccobacilli. Culture results will be available in 3 days.