18F-FDG PET/CT as a central tool in the shift from chronic Q fever to Coxiella burnetii persistent focalized infection: A consecutive case series.

Because Q fever is mostly diagnosed serologically, localizing a persistent focus of Coxiella burnetii infection can be challenging. F-fluorodeoxyglucose positron emission tomography/computed tomography (F-FDG PET/CT) could be an interesting tool in this context.We performed a retrospective study on patients diagnosed with C burnetii infection, who had undergone F-FDG PET/CT between 2009 and 2015. When positive F-FDG PET/CT results were obtained, we tried to determine if it changed the previous diagnosis by discovering or confirming a suspected focus of C burnetii infection.One hundred sixty-seven patients benefited from F-FDG PET/CT. The most frequent clinical subgroup before F-FDG PET/CT was patients with no identified focus of infection, despite high IgG1 serological titers (34%). For 59% (n = 99) of patients, a hypermetabolic focus was identified. For 62 patients (62.6%), the positive F-FDG PET/CT allowed the diagnosis to be changed. For 24 of them, (38.7%), a previously unsuspected focus of infection was discovered. Forty-two (42%) positive patients had more than 1 hypermetabolic focus. We observed 21 valvular foci, 34 vascular foci, and a high proportion of osteoarticular localizations (n = 21). We also observed lymphadenitis (n = 27), bone marrow hypermetabolism (n = 11), and 9 pulmonary localizations.We confirmed thatF-FDG PET/CT is a central tool in the diagnosis of C burnetii focalized persistent infection. We proposed new diagnostic scores for 2 main clinical entities identified using F-FDG PET/CT: osteoarticular persistent infections and lymphadenitis.

Culture-negative prosthetic joint arthritis related to Coxiella burnetii.

BACKGROUND: The number of hip and knee arthroplasty procedures is steadily increasing as life expectancy increases. Coxiella burnetii may be responsible for culture-negative prosthetic joint arthritis and is associated with antibiotic failure and repeated surgeries. We report the first case series of C. burnetii-related culture-negative prosthetic joint arthritis. METHODS: Cases were retrieved from the French National Referral center for Q fever. Diagnosis was based on (18)fluorodeoxyglucose positron emission tomography, serology, broad-range polymerase chain reaction, and C. burnetii-specific polymerase chain reaction. RESULTS: Four cases of C. burnetii-related culture-negative prosthetic joint arthritis were found. Standard bacteriologic procedures would have missed the diagnosis in all cases. Etiologic diagnosis improved the outcome in all but 1 case. CONCLUSIONS: A systematic, comprehensive diagnostic strategy should be used in culture-negative prosthetic joint arthritis, including testing for C. burnetii in endemic areas.

Q fever: a case with a vascular infection complication.

The most common clinical presentation of chronic Q fever is endocarditis with infections of aneurysms or vascular prostheses being the second most common presentation. Here, the authors report a case of vascular chronic Q fever. In this patient, a renal artery aneurysm was discovered by abdominal and pelvic CT during a systematic investigation to identify predisposing factors to chronic Q fever because of high antibody titres in a patient with valve disease.

Reactive hemophagocytic syndrome in adult systemic disease: report of twenty-six cases and literature review.

OBJECTIVE: To analyze specific clinical findings, underlying disorders, treatments, outcomes, and prognostic factors for reactive hemophagocytic syndrome (RHS) in systemic disease. METHODS: Data were collected using standardized forms as part of a French national survey. Adult cases without an underlying malignancy, diagnosed on bone marrow or lymph node biopsy, were included. RESULTS: Twenty-six cases (7 men, 19 women, mean age 47.4 +/- 17.7 years) were studied. Systemic diseases included systemic lupus erythematosus (n = 14), rheumatoid arthritis (n = 2), adult onset systemic Still's disease (n = 4), polyarteritis nodosa (n = 2), mixed connective tissue disease (n = 1), pulmonary sarcoidosis (n = 1), systemic sclerosis (n = 1), and Sjögren's syndrome (n = 1). RHS occurred in 2 distinct clinical settings in the course of systemic disease. RHS was associated with an active infection in 15 patients (bacterial infections, 10 cases; viral, 3 cases; tuberculosis, 1 case; and aspergillosis, 1 case) and with the onset of a systemic disease alone in 9 cases. Isolated RHS occurred in 2 cases. The overall mortality rate was 38.5%. Two factors were associated with mortality: corticosteroid treatment at the time of RHS diagnosis, and thrombocytopenia (odds ratio = 28, 95% confidence interval = 13.3-238.9). CONCLUSIONS: When RHS occurs in the course of an active systemic disease (situation only reported in cases of systemic lupus or adult Still's disease), immunosuppressive therapy should be used. In contrast, when RHS is present concomitantly with an active infection, immunosuppressive therapy needs to be lowered and antibiotic therapy should be instituted.