{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,18]],"date-time":"2026-08-18T01:28:44Z","timestamp":1787016524022,"version":"build-2736575974"},"reference-count":22,"publisher":"American Society for Microbiology","issue":"5","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Clin. Vaccine Immunol."],"published-print":{"date-parts":[[2012,5]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n                  <jats:p>\n                    Diagnosis of chronic Q fever is difficult. PCR and culture lack sensitivity; hence, diagnosis relies mainly on serologic tests using an immunofluorescence assay (IFA). Optimal phase I IgG cutoff titers are debated but are estimated to be between 1:800 and 1:1,600. In patients with proven, probable, or possible chronic Q fever, we studied phase I IgG antibody titers at the time of positive blood PCR, at diagnosis, and at peak levels during chronic Q fever. We evaluated 200 patients, of whom 93 (46.5%) had proven, 51 (25.5%) had probable, and 56 (28.0%) had possible chronic Q fever. Sixty-five percent of proven cases had positive\n                    <jats:named-content content-type=\"genus-species\">Coxiella burnetii<\/jats:named-content>\n                    PCR results for blood, which was associated with high phase I IgG. Median phase I IgG titers at diagnosis and peak titers in patients with proven chronic Q fever were significantly higher than those for patients with probable and possible chronic Q fever. The positive predictive values for proven chronic Q fever, compared to possible chronic Q fever, at titers 1:1,024, 1:2,048, 1:4,096, and \u22651:8,192 were 62.2%, 66.7%, 76.5%, and \u226586.2%, respectively. However, sensitivity dropped to &lt;60% when cutoff titers of \u22651:8,192 were used. Although our study demonstrated a strong association between high phase I IgG titers and proven chronic Q fever, increasing the current diagnostic phase I IgG cutoff to &gt;1:1,024 is not recommended due to increased false-negative findings (sensitivity &lt; 60%) and the high morbidity and mortality of untreated chronic Q fever. Our study emphasizes that serologic results are not diagnostic on their own but should always be interpreted in combination with clinical parameters.\n                  <\/jats:p>","DOI":"10.1128\/cvi.05724-11","type":"journal-article","created":{"date-parts":[[2012,3,23]],"date-time":"2012-03-23T11:47:23Z","timestamp":1332503243000},"page":"787-790","source":"Crossref","is-referenced-by-count":31,"title":["Microbiological Challenges in the Diagnosis of Chronic Q Fever"],"prefix":"10.1128","volume":"19","author":[{"given":"Linda M.","family":"Kampschreur","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jan Jelrik","family":"Oosterheert","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Annemarie M. C.","family":"Koop","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marjolijn C. A.","family":"Wegdam-Blans","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Corine E.","family":"Delsing","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chantal P.","family":"Bleeker-Rovers","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Monique G. L.","family":"De Jager-Leclercq","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Cornelis A. R.","family":"Groot","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tom","family":"Sprong","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marrigje H.","family":"Nabuurs-Franssen","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nicole H. M.","family":"Renders","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marjo E.","family":"van Kasteren","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yvonne","family":"Soethoudt","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sybrandus N.","family":"Blank","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marjolijn J. H.","family":"Pronk","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rolf H. H.","family":"Groenwold","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Andy I. M.","family":"Hoepelman","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Peter C.","family":"Wever","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"235","published-online":{"date-parts":[[2012,3,21]]},"reference":[{"key":"key20180919073606_B1","doi-asserted-by":"crossref","first-page":"635","DOI":"10.1007\/s10096-007-0357-6","article-title":"Coxiella burnetii infection of aortic aneurysms or vascular grafts: report of 30 new cases and evaluation of outcome","volume":"26","author":"Botelho-Nevers","year":"2007","journal-title":"Eur. J. Clin. Microbiol. Infect. Dis."},{"key":"key20180919073606_B2","first-page":"382","article-title":"Q fever in the Netherlands from 2007 to 2010","volume":"68","author":"Delsing","year":"2010","journal-title":"Neth. J. Med."},{"key":"key20180919073606_B3","doi-asserted-by":"crossref","first-page":"189","DOI":"10.1128\/CDLI.1.2.189-196.1994","article-title":"Q fever serology: cutoff determination for microimmunofluorescence","volume":"1","author":"Dupont","year":"1994","journal-title":"Clin. Diagn. Lab. Immunol."},{"key":"key20180919073606_B4","doi-asserted-by":"crossref","first-page":"312","DOI":"10.1086\/321889","article-title":"Risks factors and prevention of Q fever endocarditis","volume":"33","author":"Fenollar","year":"2001","journal-title":"Clin. Infect. Dis."},{"key":"key20180919073606_B5","doi-asserted-by":"crossref","first-page":"4919","DOI":"10.1128\/JCM.42.11.4919-4924.2004","article-title":"Molecular detection of Coxiella burnetii in the sera of patients with Q fever endocarditis or vascular infection","volume":"42","author":"Fenollar","year":"2004","journal-title":"J. Clin. Microbiol."},{"key":"key20180919073606_B6","doi-asserted-by":"crossref","first-page":"350","DOI":"10.3201\/eid1703.100882","article-title":"Q fever in France, 1985\u20132009","volume":"17","author":"Frankel","year":"2011","journal-title":"Emerg. Infect. Dis."},{"key":"key20180919073606_B7","doi-asserted-by":"crossref","first-page":"1013","DOI":"10.1093\/cid\/cir132","article-title":"Chronic Q fever: different serological results in three countries\u2014results of a follow-up study 6 years after a point source outbreak","volume":"52","author":"Healy","year":"2011","journal-title":"Clin. Infect. Dis."},{"key":"key20180919073606_B8","doi-asserted-by":"crossref","first-page":"39","DOI":"10.1016\/j.jinf.2010.10.008","article-title":"Serologic assessment of the risk of developing chronic Q fever in cohorts of acutely infected individuals","volume":"62","author":"Hung","year":"2011","journal-title":"J. Infect."},{"key":"key20180919073606_B9","doi-asserted-by":"crossref","first-page":"1692","DOI":"10.1128\/JCM.02596-10","article-title":"Chronic Q fever-related dual-pathogen endocarditis: case series of three patients","volume":"49","author":"Kampschreur","year":"2011","journal-title":"J. Clin. Microbiol."},{"key":"key20180919073606_B10","doi-asserted-by":"crossref","first-page":"1337","DOI":"10.1086\/515401","article-title":"From acute Q fever to endocarditis: serological follow-up strategy","volume":"44","author":"Landais","year":"2007","journal-title":"Clin. Infect. Dis."},{"key":"key20180919073606_B11","doi-asserted-by":"crossref","first-page":"518","DOI":"10.1128\/CMR.12.4.518","article-title":"Q fever","volume":"12","author":"Maurin","year":"1999","journal-title":"Clin. Microbiol. 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Vaccine Immunol."},{"key":"key20180919073606_B18","doi-asserted-by":"crossref","first-page":"749","DOI":"10.1093\/cid\/cir438","article-title":"Chronic Q fever: relevance of serology","volume":"53","author":"Sunder","year":"2011","journal-title":"Clin. Infect. Dis."},{"key":"key20180919073606_B19","doi-asserted-by":"crossref","first-page":"232","DOI":"10.1086\/510389","article-title":"Role of sex, age, previous valve lesion, and pregnancy in the clinical expression and outcome of Q fever after a large outbreak","volume":"44","author":"Tissot-Dupont","year":"2007","journal-title":"Clin. Infect. Dis."},{"key":"key20180919073606_B20","doi-asserted-by":"crossref","DOI":"10.2807\/ese.15.12.19520-en","article-title":"Q fever in the Netherlands: an update on the epidemiology and control measures","volume":"15","author":"van der Hoek","year":"2010","journal-title":"Euro. Surveill."},{"key":"key20180919073606_B21","doi-asserted-by":"crossref","first-page":"1431","DOI":"10.1093\/cid\/cir234","article-title":"Follow-up of 686 patients with acute Q fever and detection of chronic infection","volume":"52","author":"van der Hoek","year":"2011","journal-title":"Clin. Infect. Dis."},{"key":"key20180919073606_B22","doi-asserted-by":"crossref","first-page":"247","DOI":"10.1016\/j.jinf.2011.12.014","article-title":"Chronic Q fever: review of the literature and a proposal of new diagnostic criteria","volume":"64","author":"Wegdam-Blans","year":"2012","journal-title":"J. Infect."}],"container-title":["Clinical and Vaccine Immunology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1128\/CVI.05724-11","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,1,6]],"date-time":"2022-01-06T14:43:58Z","timestamp":1641480238000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.asm.org\/doi\/10.1128\/CVI.05724-11"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2012,3,21]]},"references-count":22,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2012,4,26]]},"published-print":{"date-parts":[[2012,5]]}},"alternative-id":["10.1128\/CVI.05724-11"],"URL":"https:\/\/doi.org\/10.1128\/cvi.05724-11","relation":{},"ISSN":["1556-6811","1556-679X"],"issn-type":[{"value":"1556-6811","type":"print"},{"value":"1556-679X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2012,3,21]]}}}