Q fever sternum osteomyelitis in a patient with history of cardiovascular surgery: A case report from China.

This article reports a rare case of sternal osteomyelitis caused by Coxiella burnetii. The patient, a 59-year-old male with a history of aortic dissection and hypertension, had undergone ascending aorta replacement and aortic valvuloplasty. He was admitted in May 2022 due to a chest mass that had been enlarging since its discovery in October 2021. Despite antibiotic treatment, the symptoms did not improve, and he experienced recurrent low-grade fevers. Upon admission, CT imaging revealed multiple mediastinal lymph node enlargements and a cystic shadow anterior to the sternum handle. The infection was confirmed as Coxiella burnetii through surgical debridement and metagenomic next-generation sequencing (mNGS). The treatment was subsequently changed to doxycycline and hydroxychloroquine. Positron emission computed tomography with 18 F-fluorodeoxyglucose ([18 F] FDG PET/CT) imaging showed that the infection was localized to the sternum, excluding vascular and implant infections. The patient completed an 18-month course of antibiotics, leading to controlled infection and normalized renal function. This case highlights the complexities of diagnosing and managing Q fever osteomyelitis in patients post-cardiovascular surgery, demonstrating the crucial roles of mNGS and [18 F] FDG PET/CT in rapid diagnosis and effective treatment. These findings provide valuable insights and guidance for managing similar cases in the future.