Karius testing in the identification of <i>Coxiella burnetii</i> infective endocarditis presenting with acute ischaemic stroke

Our case highlights an atypical presentation of <i>Coxiella burnetii</i> endocarditis with acute ischaemic stroke in a male patient in his 60s. The patient had undergone a congenital bicuspid aortic valve replacement with a bioprosthetic valve and an ascending aortic root graft with a pacemaker. He experienced intermittent fevers, chills and malaise over 15 months leading up to his presentation. During our diagnostic process, we used the newly developed Karius test, which detects microbial cell-free DNA in the patient's serum. The patient was treated with doxycycline and hydroxychloroquine for 24 months along with surgical removal and replacement of his aortic valve and graft. Our case underscores the utility of the Karius test and the essential role of neurology in the multidisciplinary team.