AUTHOR=Bozza Silvia , Graziani Alessandro , Borghi Monica , Marini Daniele , Duranti Michele , Camilloni Barbara 

TITLE=Case report: Coxiella burnetii endocarditis in the absence of evident exposure

JOURNAL=Frontiers in Medicine

VOLUME=10

YEAR=2023

URL=https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2023.1220205

DOI=10.3389/fmed.2023.1220205

ISSN=2296-858X

ABSTRACT=<p>Q fever is a worldwide zoonotic disease caused by <italic>Coxiella burnetii</italic>. In humans, it can manifest clinically as an acute or chronic disease and endocarditis, the most frequent complication of chronic Q fever is associated with the greatest morbidity and mortality. We report a severe case of endocarditis in a 55-year-old man with a history of aortic valve replacement affected by monoclonal gammopathy of undetermined significance (MGUS), and living in a non-endemic area for <italic>C. burnetii</italic>. After two episodes of fever of unknown origin (FUO), occurring 2 years apart and characterized by negative blood cultures, a serological diagnosis of Q fever endocarditis was performed even though the patient did not refer to possible past exposure to <italic>C. burnetii</italic>. Since people with preexisting valvular heart disease, when infected with <italic>C. burnetii</italic>, have reported a 40% risk of Q fever endocarditis, clinicians should maintain a high index of suspicion for infective endocarditis in all patients with FUO even when the exposure to <italic>C. burnetii</italic> appears to be unlikely.</p>