Could remembering the prozone phenomenon shorten our diagnostic journey in brucellosis? A case of Brucella spondylodiscitis

We reviewed a case of Brucella spondylodiscitis admitted to a referral, university hospital, in Ankara, Turkey. A 75-year-old female was referred to our hospital with low back pain. Previous magnetic resonance imaging yielded cortical destruction of T9–10 and T12–L2 vertebral bodies, focal infectious foci at discs within this range, significant microabscesses at paravertebral areas, which lead to the diagnosis of spondylodiscitis. History of consumption of unpasteurized dairy products led us to first suspect brucellosis yet, the serum agglutination test and blood culture were negative and did mislead us to several other, sometimes invasive, diagnostic tests. The final diagnosis was reached by culturing the specimen obtained through fine-needle aspiration from the paravertebral microabscesses. The exhausting diagnostic journey that started with the suspicion of tuberculosis or malignancy ended with a diagnosis of brucellosis. Brucellosis should be considered in all patients with osteoarthritic complaints in endemic regions, and the “prozone phenomenon” should be kept in mind, before proceeding to high-tech lab tests, imaging, or invasive procedures.