title: Characteristics of hospitalized acute Q fever patients during a large epidemic, The Netherlands.
abstract: BACKGROUND
  From 2007 to 2009, The Netherlands experienced a major Q fever epidemic, with higher hospitalization rates than the 2-5% reported in the literature for acute Q fever pneumonia and hepatitis. We describe epidemiological and clinical features of hospitalized acute Q fever patients and compared patients presenting with Q fever pneumonia with patients admitted for other forms of community-acquired pneumonia (CAP). We also examined whether proximity to infected ruminant farms was a risk factor for hospitalization.
  
  
  METHODS
  A retrospective cohort study was conducted for all patients diagnosed and hospitalized with acute Q fever between 2007 and 2009 in one general hospital situated in the high incidence area in the south of The Netherlands. Pneumonia severity scores (PSI and CURB-65) of acute Q fever pneumonia patients (defined as infiltrate on a chest x-ray) were compared with data from CAP patients. Hepatitis was defined as a >twofold the reference value for alanine aminotransferase and for bilirubin.
  
  
  RESULTS
  Among the 183 hospitalized acute Q fever patients, 86.0% had pneumonia. Elevated liver enzymes (alanine aminotransferase) were found in 32.3% of patients, although hepatitis was not observed in any of them. The most frequent clinical signs upon presentation were fever, cough and dyspnoea. The median duration of admission was five days. Acute Q fever pneumonia patients were younger, had less co-morbidity, and lower PSI and CURB-65 scores than other CAP patients. Anecdotal information from attending physicians suggests that some patients were admitted because of severe subjective dyspnoea, which was not included in the scoring systems. Proximity to an infected ruminant farm was not associated with hospitalization.
  
  
  CONCLUSIONS
  Hospitalized Dutch acute Q fever patients mostly presented with fever and pneumonia. Patients with acute Q fever pneumonia were hospitalized despite low PSI and CURB-65 scores, presumably because subjective dyspnoea was not included in the scoring systems.
authors.affiliation: Department of Medical Microbiology and Infection Control, Jeroen Bosch Hospital, 's-Hertogenbosch, the Netherlands; Centre for Infectious Disease Control, National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands.
authors.forename: Cornelia C H
authors.initials: CC
authors.lastname: Wielders
authors.affiliation: Centre for Infectious Disease Control, National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands; Department of Internal Medicine, Bernhoven Hospital, Uden, the Netherlands.
authors.forename: Annemarie M H
authors.initials: AM
authors.lastname: Wuister
authors.affiliation: Department of Pulmonary Diseases, Jeroen Bosch Hospital, 's-Hertogenbosch, the Netherlands.
authors.forename: Veerle L
authors.initials: VL
authors.lastname: de Visser
authors.affiliation: Department of Internal Medicine, Bernhoven Hospital, Uden, the Netherlands.
authors.forename: Monique G
authors.initials: MG
authors.lastname: de Jager-Leclercq
authors.affiliation: Department of Pulmonary Diseases, Bernhoven Hospital, Uden, the Netherlands.
authors.forename: Cornelis A R
authors.initials: CA
authors.lastname: Groot
authors.affiliation: Centre for Infectious Disease Control, National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands.
authors.forename: Frederika
authors.initials: F
authors.lastname: Dijkstra
authors.affiliation: Centre for Infectious Disease Control, National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands.
authors.forename: Arianne B
authors.initials: AB
authors.lastname: van Gageldonk-Lafeber
authors.affiliation: Centre for Infectious Disease Control, National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands; Institute for Risk Assessment Sciences, Faculty of Veterinary Sciences, Utrecht University, Utrecht, the Netherlands.
authors.forename: Jeroen P G
authors.initials: JP
authors.lastname: van Leuken
authors.affiliation: Department of Medical Microbiology and Infection Control, Jeroen Bosch Hospital, 's-Hertogenbosch, the Netherlands.
authors.forename: Peter C
authors.initials: PC
authors.lastname: Wever
authors.affiliation: Centre for Infectious Disease Control, National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands.
authors.forename: Wim
authors.initials: W
authors.lastname: van der Hoek
authors.affiliation: Department of Medical Microbiology and Infection Control, Jeroen Bosch Hospital, 's-Hertogenbosch, the Netherlands; Centre for Infectious Disease Control, National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands.
authors.forename: Peter M
authors.initials: PM
authors.lastname: Schneeberger
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D004781:Environmental Exposure; D058872:Epidemics / Q000706:statistics & numerical data*; D005260:Female; D005500:Follow-Up Studies; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D011014:Pneumonia / Q000150:complications / Q000453:epidemiology; D011778:Q Fever / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000382:microbiology; D011859:Radiography; D013997:Time Factors; D055815:Young Adult