title: Q fever: a neglected zoonosis in Saudi Arabia.
abstract: OBJECTIVE
  Infection due to Coxiella burnetii (C burnetii), the causative agent of Q fever is rarely sought for in clinical practice. This study was performed to detect C burnetii infection in patients with pyrexia of undetermined cause (PUC).
  
  
  METHODS
  This is a prospective study conducted at King Khalid University Hospital, Riyadh be.tween March 2011 and January 2013.
  
  
  METHODS
  A total of 3 mL venous blood was collected from 51 patients with PUC at King Khalid University Hospital, Riyadh. This group of patients included 30 males and 21 females (mean age 33.9 [21.3] years) with the history of febrile illness ranging between 4 and 8 weeks. A control group of 50 healthy individuals comprising 39 males and 11 females (mean age 27 [9] years) was also included in the study. Detection of phase II C burnetii-specific IgG antibodies was performed by immunofluorescence assay, and a titer of > 1:64 was considered positive.
  
  
  RESULTS
  Phase II C burnetii-specific IgG antibodies were detected in 18 (35.2%) patients out of the total 51 tested. Two (4%) individuals out of 50 in the control group tested positive for anti-C burnetii IgG antibodies. The proportion of positive results among the patients was significantly higher than the controls (P < .0002, 95% CI, 15.09-46.25). The antibody titer range was between 1:128 and 1:1024 where 6 patients had titers of 1:256, 5 had 1:512, 4 had 1024, and 3 had 1:128.
  
  
  CONCLUSIONS
  The evidence of C burnetii infection in a sizable number of patients emphasizes the need for inclusion of serologic investigations for Q fever in patients with PUC.
authors.affiliation: Dr. Adel Almogren, Pathology, Immunology Unit,, College of Medicine, King Saud University,, PO Box 2925 Riyadh 11461,, Saudi Arabia, T:966-11-467-1843, F:966-11-467-1925, almogren@ksu.edu.sa.
authors.forename: Adel
authors.initials: A
authors.lastname: Almogren
authors.forename: Zahid
authors.initials: Z
authors.lastname: Shakoor
authors.forename: Rana
authors.initials: R
authors.lastname: Hasanato
authors.forename: Mustafa Hussein
authors.initials: MH
authors.lastname: Adam
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D016022:Case-Control Studies; D002648:Child; D016997:Coxiella burnetii / Q000302:isolation & purification*; D005260:Female; D005334:Fever / Q000175:diagnosis / Q000382:microbiology*; D005455:Fluorescent Antibody Technique; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011778:Q Fever / Q000175:diagnosis / Q000453:epidemiology*; D012529:Saudi Arabia / Q000453:epidemiology; D055815:Young Adult; D015047:Zoonoses / Q000175:diagnosis / Q000453:epidemiology* / Q000382:microbiology
chemical_list: D007074:Immunoglobulin G