title: Impact of rapid detection of viral and atypical bacterial pathogens by real-time polymerase chain reaction for patients with lower respiratory tract infection.
abstract: BACKGROUND
  Rapid diagnostic tests with a high sensitivity for lower respiratory tract infection (LRTI) could lead to improved patient care and reduce unnecessary antibiotic use and associated costs. Diagnostic yields, feasibility, and costs of real-time polymerase chain reaction (PCR) of nasopharyngeal and oropharyngeal swab specimens in the routine diagnostic work-up for LRTI were determined.
  
  
  METHODS
  In a randomized controlled trial, nasopharyngeal and oropharyngeal swab specimens from patients admitted for antibiotic treatment of LRTI were evaluated by means of real-time PCR for respiratory viruses and atypical pathogens, as well as by conventional diagnostic procedures. Real-time PCR results for patients in the intervention group were reported to the treating physician; results for patients in the control group were not made available.
  
  
  RESULTS
  A total of 107 patients (mean age [+/- standard deviation], 63.6+/-16.3 years) were included, of whom 55 were allocated to the intervention group. The pathogens detected most frequently were influenza virus (14 patients), Streptococcus pneumoniae (8), coronavirus (6), Staphylococcus aureus (5), and rhinoviruses (5). Real-time PCR increased the diagnostic yield from 23 cases (21% of patients) to 47 cases (43% of patients), compared with conventional diagnostic tests. The detection of viral pathogens by PCR was associated with the winter season, less infiltrates on chest radiographs, lower C-reactive protein levels, and shorter duration of symptoms. Use of real-time PCR results resulted in partial or total cessation of antibiotic treatment for 6 patients (11%; 95% confidence interval, 2-19), but overall antibiotic use was comparable in the intervention group and the control group (median duration of treatment, 10.0 vs. 9.0 days; P=not significant). Use of real-time PCR increased treatment and diagnostic costs with 318.17 per patient.
  
  
  CONCLUSIONS
  Implementation of real-time PCR for the etiological diagnosis of LRTI increased the diagnostic yield considerably, but it did not reduce antibiotic use or costs.
authors.affiliation: Division of Medicine, Department of Internal Medicine and Infectious Diseases, University Medical Center, Utrecht, The Netherlands.
authors.forename: Jan Jelrik
authors.initials: JJ
authors.lastname: Oosterheert
authors.forename: Anton M
authors.initials: AM
authors.lastname: van Loon
authors.forename: Rob
authors.initials: R
authors.lastname: Schuurman
authors.forename: Andy I M
authors.initials: AI
authors.lastname: Hoepelman
authors.forename: Eelko
authors.initials: E
authors.lastname: Hak
authors.forename: Steven
authors.initials: S
authors.lastname: Thijsen
authors.forename: George
authors.initials: G
authors.lastname: Nossent
authors.forename: Margriet M E
authors.initials: MM
authors.lastname: Schneider
authors.forename: Willem M N
authors.initials: WM
authors.lastname: Hustinx
authors.forename: Marc J M
authors.initials: MJ
authors.lastname: Bonten
mesh_terms: D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D000890:Anti-Infective Agents; D001419:Bacteria / Q000235:genetics / Q000302:isolation & purification; D001424:Bacterial Infections / Q000175:diagnosis* / Q000188:drug therapy / Q000191:economics / Q000382:microbiology; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016133:Polymerase Chain Reaction; D012141:Respiratory Tract Infections / Q000175:diagnosis* / Q000188:drug therapy* / Q000191:economics / Q000382:microbiology; D012680:Sensitivity and Specificity; D014777:Virus Diseases / Q000175:diagnosis* / Q000188:drug therapy / Q000191:economics / Q000821:virology; D014780:Viruses / Q000235:genetics / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents