title: Seroprevalence of Q Fever in Patients Undergoing Heart Valve Replacement Surgery.
abstract: Q fever, caused by the rickettsia Coxiella burnetii, is a worldwide zoonotic disease with both acute and chronic manifestations. Endocarditis is the principal chronic manifestation. Q fever can easily be mistaken for degenerative valve disease due to its indolent presentation, the fastidious nature of the organism (routine cultures are negative), and the absence of a typical echocardiographic and macroscopic appearance for endocarditis. Prosthetic valve failure, with associated morbidity and mortality, have been described following unrecognized infections.
  
  
  
  Previous studies have documented the value of screening strategies in areas of high prevalence. Hence, a pilot study was conducted in a low-prevalence setting, in which 139 patients at two tertiary cardiac centers attending for elective valve replacement for degenerative valvular disease underwent testing for chronic Q fever infection by serological and molecular methods on blood and valve tissue.
  
  
  
  Five patients (3.7%) had serological evidence of past exposure to Q fever (consistent with rates in the literature). None had evidence of chronic Q fever endocarditis. The cost of adopting a universal screening strategy is around £40,000 per case (if serology is used to screen patients prior to surgery).
  
  
  
  Alternative and more cost-effective methods for identifying clinically quiet cases of chronic Q fever endocarditis are required.
authors.affiliation: Public Health Wales, Cardiff, Wales, UK. Electronic correspondence: owen.seddon2@wales.nhs.uk.
authors.forename: Owen
authors.initials: O
authors.lastname: Seddon
authors.affiliation: Bristol Heart Institute, Bristol Royal Infirmary, Bristol, UK.
authors.forename: Reza
authors.initials: R
authors.lastname: Ashrafi
authors.affiliation: Rare and Imported Pathogens Laboratory, Public Health England, Wiltshire, UK.
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Duggan
authors.affiliation: Public Health Wales, Cardiff, Wales, UK.
authors.forename: Rhianydd
authors.initials: R
authors.lastname: Rees
authors.affiliation: University Hospital of Wales, Cardiff, Wales, UK.
authors.forename: Christine
authors.initials: C
authors.lastname: Tan
authors.affiliation: James Cook University Hospital, Middlesbrough, UK.
authors.forename: John
authors.initials: J
authors.lastname: Williams
authors.affiliation: International Severe Acute Respiratory & Emerging Infection Consortium (ISARIC).
authors.forename: Gail
authors.initials: G
authors.lastname: Carson
authors.affiliation: Public Health Wales, Cardiff, Wales, UK.|University Hospital of Wales, Cardiff, Wales, UK.
authors.forename: Brendan
authors.initials: B
authors.lastname: Healy
mesh_terms: D001431:Bacteriological Techniques; D016997:Coxiella burnetii / Q000235:genetics / Q000302:isolation & purification*; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D004697:Endocarditis, Bacterial / Q000097:blood / Q000453:epidemiology* / Q000382:microbiology; D006349:Heart Valve Diseases / Q000097:blood / Q000453:epidemiology / Q000382:microbiology / Q000601:surgery*; D019918:Heart Valve Prosthesis Implantation; D006351:Heart Valves / Q000382:microbiology / Q000601:surgery*; D006801:Humans; D010865:Pilot Projects; D016133:Polymerase Chain Reaction; D011237:Predictive Value of Tests; D015995:Prevalence; D011778:Q Fever / Q000097:blood / Q000453:epidemiology* / Q000382:microbiology; D016036:Seroepidemiologic Studies; D012698:Serologic Tests; D062606:Tertiary Care Centers; D006113:United Kingdom / Q000453:epidemiology
chemical_list: D004269:DNA, Bacterial