title: Improved diagnosis of the etiology of community-acquired pneumonia with real-time polymerase chain reaction.
abstract: BACKGROUND
  Community-acquired pneumonia (CAP) remains an important cause of morbidity and mortality. Polymerase chain reaction (PCR) has been shown to be more sensitive than current standard microbiological methods and, therefore, may improve the accuracy of microbiological diagnosis for patients with CAP.
  
  
  METHODS
  Conventional detection techniques and multiplex real-time PCR for atypical bacteria and respiratory viruses were performed on samples collected from 105 adults enrolled in a prospective study. An infiltrate was visible on each patient's chest radiograph, and a pneumonia severity index score was determined for each patient.
  
  
  RESULTS
  Microbiological diagnoses were determined for 52 (49.5%) of 105 patients by conventional techniques and for 80 (76%) of 105 patients by real-time PCR. The time to obtain the result of real-time PCR could be reduced to 6 h. PCR methodology was significantly more sensitive for the detection of atypical pathogens and viruses (P< or =.001). Respiratory viral infections and mixed infections were detected in 15 (14.2%) and 3 (2.8%) of 105 patients, respectively, by conventional methods, but were detected in 59 (56.2%) and 28 (26.5%) of 105, respectively, by real-time PCR. Presence of a mixed infection was significantly associated with severe pneumonia (P=.002). Human rhinoviruses and coronaviruses, OC43 and 229E, were frequently identified pathogens.
  
  
  CONCLUSIONS
  The combined real-time PCR assay is more sensitive for diagnosis of the main viruses and atypical bacteria that cause CAP compared with conventional methods, and obtains results in a clinically relevant time period.
authors: Department of Medical Microbiology, Leiden University Medical Center, Leiden, The Netherlands.
authors: Kate E
authors: KE
authors: Templeton
authors: Sitha A
authors: SA
authors: Scheltinga
authors: Willian C J F M
authors: WC
authors: van den Eeden
authors: A Willy
authors: AW
authors: Graffelman
authors: Peterhans J
authors: PJ
authors: van den Broek
authors: Eric C J
authors: EC
authors: Claas
mesh_terms: D000293:Adolescent; D000328:Adult; D000375:Aging; D017714:Community-Acquired Infections / Q000175:diagnosis* / Q000453:epidemiology / Q000382:microbiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D011014:Pneumonia / Q000175:diagnosis* / Q000453:epidemiology / Q000382:microbiology*; D016133:Polymerase Chain Reaction / Q000379:methods*; D012307:Risk Factors