{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,18]],"date-time":"2026-03-18T14:01:55Z","timestamp":1773842515680,"version":"3.50.1"},"reference-count":9,"publisher":"BMJ","issue":"7","content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Case Rep"],"accepted":{"date-parts":[[2021,6,24]]},"published-print":{"date-parts":[[2021,7]]},"abstract":"<jats:p>A 79-year-old man was admitted to our ward with symptomatic heart failure 2\u2009months after aortic valve replacement due to severe aortic stenosis. On the third day following admission, he became febrile (&gt;38\u00b0C) while manifesting an increase in inflammatory markers. Endocarditis was suspected despite negative blood cultures. Echocardiogram (transthoracic and transesophageal) did not describe any vegetations. No hypermetabolic lesions were described on the Positron emission tomography scan. Empirical antibiotics were started but the fever persisted. Serologies revealed a <jats:italic>Coxiella burnetii<\/jats:italic> IgG phase II titre of 1:800, high erythrocyte sedimentation rate. Positive antinuclear antibodies, antibeta2 IgM and anticardiolipin supported a diagnosis of acute Q fever endocarditis. Doxycycline and hydroxychloroquine were started with total resolution of symptoms. This case illustrates the difficulty of diagnosing Q fever endocarditis during its acute phase, not only because vegetations can be minimal or absent, a challenge that is further compounded by a complex presentation of immunological markers.<\/jats:p>","DOI":"10.1136\/bcr-2021-243743","type":"journal-article","created":{"date-parts":[[2021,7,21]],"date-time":"2021-07-21T13:01:50Z","timestamp":1626872510000},"page":"e243743","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":4,"title":["The diagnostic challenge of acute Q fever endocarditis"],"prefix":"10.1136","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2820-3259","authenticated-orcid":false,"given":"Torcato","family":"Moreira Marques","sequence":"first","affiliation":[{"name":"Internal Medicine Department, Hospital de Santa Marta - Centro Hospitalar Universit\u00e1rio de Lisboa Central, Lisboa, Portugal"},{"name":"NOVA Medical School, Faculdade de Ci\u00eancias M\u00e9dicas da Universidade NOVA de Lisboa, Lisboa, Portugal"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8748-0446","authenticated-orcid":false,"given":"Louren\u00e7o","family":"Cruz","sequence":"additional","affiliation":[{"name":"Internal Medicine Department, Hospital de Santa Marta - Centro Hospitalar Universit\u00e1rio de Lisboa Central, Lisboa, Portugal"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8007-1882","authenticated-orcid":false,"given":"Raquel","family":"Soares","sequence":"additional","affiliation":[{"name":"Internal Medicine Department, Hospital de Santa Marta - Centro Hospitalar Universit\u00e1rio de Lisboa Central, Lisboa, Portugal"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9509-3155","authenticated-orcid":false,"given":"Sofia","family":"Eus\u00e9bio","sequence":"additional","affiliation":[{"name":"Internal Medicine Department, Hospital de Santa Marta - Centro Hospitalar Universit\u00e1rio de Lisboa Central, Lisboa, Portugal"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"239","published-online":{"date-parts":[[2021,7,21]]},"reference":[{"key":"2025082707583851000_14.7.e243743.1","doi-asserted-by":"crossref","DOI":"10.1001\/jamanetworkopen.2018.1580","article-title":"Clinical features and complications of Coxiella burnetii infections from the French national reference center for Q fever","volume":"1","author":"Melenotte","year":"2018","journal-title":"JAMA Netw Open"},{"key":"2025082707583851000_14.7.e243743.2","doi-asserted-by":"publisher","DOI":"10.3201\/eid2107.130955"},{"key":"2025082707583851000_14.7.e243743.3","doi-asserted-by":"publisher","DOI":"10.1128\/CMR.00045-16"},{"key":"2025082707583851000_14.7.e243743.4","doi-asserted-by":"publisher","DOI":"10.1093\/cid\/civ956"},{"key":"2025082707583851000_14.7.e243743.5","doi-asserted-by":"publisher","DOI":"10.1086\/368219"},{"key":"2025082707583851000_14.7.e243743.6","doi-asserted-by":"publisher","DOI":"10.1093\/cid\/cit191"},{"key":"2025082707583851000_14.7.e243743.7","doi-asserted-by":"publisher","DOI":"10.1016\/S1473-3099(10)70135-3"},{"key":"2025082707583851000_14.7.e243743.8","doi-asserted-by":"crossref","first-page":"157","DOI":"10.1016\/j.hrtlng.2007.04.002","article-title":"Q fever bioprosthetic aortic valve endocarditis (PVE) successfully treated with doxycycline monotherapy","volume":"37","author":"Krol","year":"2008","journal-title":"Heart Lung"},{"key":"2025082707583851000_14.7.e243743.9","doi-asserted-by":"publisher","DOI":"10.1093\/infdis\/166.5.1097"}],"container-title":["BMJ Case Reports"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/bcr-2021-243743","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,8,27]],"date-time":"2025-08-27T14:58:48Z","timestamp":1756306728000},"score":1,"resource":{"primary":{"URL":"https:\/\/casereports.bmj.com\/lookup\/doi\/10.1136\/bcr-2021-243743"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,7]]},"references-count":9,"journal-issue":{"issue":"7","published-online":{"date-parts":[[2021,7,21]]},"published-print":{"date-parts":[[2021,7]]}},"alternative-id":["10.1136\/bcr-2021-243743"],"URL":"https:\/\/doi.org\/10.1136\/bcr-2021-243743","relation":{},"ISSN":["1757-790X"],"issn-type":[{"value":"1757-790X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,7]]}}}