A contemporary 16-year review of Coxiella burnetii infective endocarditis in a tertiary cardiac center in Queensland, Australia.

Background: Coxiella burnetii endocarditis can be difficult to diagnose leading to delays in treatment. This retrospective case series study was undertaken to understand the epidemiologic trends and clinical features of Q fever endocarditis in Southeast Queensland, Australia.

Methods: Clinical records of patients from a single center with coding diagnosis of C. burnetii, or serology consistent with chronic Q fever, were reviewed from 1999 to 2015. Data from patients with probable or confirmed Q fever endocarditis was abstracted.

Results: Thirteen patients had confirmed and 5 had probable Q fever endocarditis. Median age at diagnosis in confirmed cases was 60 years. In confirmed cases, 92% (12/13) of patients had an underlying valvular defect. Two patients in the confirmed cases had serology not consistent with a diagnosis of Q fever endocarditis. Eight patient records noted retrospective diagnosis of Q fever endocarditis after surgery.

Conclusions: As pre-existing valve pathology is a major risk for developing endocarditis, prophylactic strategies such as targeted echocardiography and Q fever vaccination could be considered to reduce the incidence of Q fever endocarditis.