[Chronic Q fever. Literature review and a case report of culture negative spondylodiscitis].

Abstract

Introduction: Fever is a cosmopolit zoonosis due to Coxiella burnetii. The diagnosis of chronic Q fever can be really misleading. The growth of this bacterium is difficult and blood cultures are often negatives.

Case presentation: We rapport here the case of a 69-year-old man presenting with an alteration of his general condition and low back pain. He suffered from a well-controlled HIV infection and lower limb arteriopathy treated with a cross-femoral bypass. A computed tomography scan revealed a L3-L4 abscessed spondylodiscitis but multiple blood cultures remained sterile, and the transthoracic echocardiography was normal. PET scan showed a hypermetabolism on L3-L4 vertebrae but also indicated an intense uptake of the cross-femoral bypass. C. burnetii serology was in favour of a chronic Q fever. The management of this chronic Q fever needed a multidisciplinary discussion. Three months after the treatment initiation, C. burnetii serology was reduced by a titer and has stabilized 6months to a year.

Conclusion: Chronic Q fever and mostly osteoarticular diseases are difficult to diagnose. We have to evoke the diagnosis of osteoarticular chronic Q fever in case of insidious inflammatory syndrome, negatives blood cultures spondylodiscitis especially when associated to endocarditis or vascular infection, and in case of spondylodiscitis with a granulomatous histology without Mycobacterium tuberculosis. Although there are many complementary tests (PET scanner, PCR), serology remains the cornerstone of diagnosis.