Detection of respiratory viruses and Legionella spp. by real-time polymerase chain reaction in patients with community acquired pneumonia

Scand J Infect Dis. 2009;41(1):45-50. doi: 10.1080/00365540802448799.

Abstract

We conducted a study on throat swabs obtained from a group of hospitalized patients with community acquired pneumonia (CAP). Throat swab specimens from 242 adults admitted to hospital with CAP were tested. In total, 1 or more aetiological agents were identified by real-time PCR in 55 (23%) patients. The most frequently detected pathogens were coronavirus (17%), parainfluenza virus (6%) and influenza virus (4%). Overall, viral pathogens were identified by conventional techniques in 7 (2%) patients, and real-time PCR in 50 (21%) patients (p<0.0001). The diagnostic yield increased from 137 cases (57% of patients using conventional microbiological assays) to 158 cases (65% of patients using real-time PCR assays and conventional microbiological assays; p=0.06). A significantly higher percentage of mortality was present in patients with a mixed bacterial and viral infection. L. pneumophila PCR was positive in only 3 out of 11 cases (27%) of Legionnaires' disease (LD). This study demonstrates that real-time PCR can increase the number of microbiological detections of respiratory pathogens, mainly as a result of detection of respiratory viruses.

MeSH terms

  • Adolescent
  • Adult
  • Community-Acquired Infections* / diagnosis
  • Community-Acquired Infections* / microbiology
  • Community-Acquired Infections* / virology
  • Culture Media
  • DNA, Bacterial / analysis
  • DNA, Bacterial / isolation & purification
  • DNA, Viral / analysis
  • DNA, Viral / isolation & purification
  • Hospitalization
  • Humans
  • Legionella pneumophila / classification
  • Legionella pneumophila / genetics
  • Legionella pneumophila / isolation & purification
  • Legionella* / classification
  • Legionella* / genetics
  • Legionella* / isolation & purification
  • Legionnaires' Disease / diagnosis
  • Legionnaires' Disease / microbiology
  • Pharynx / microbiology
  • Pharynx / virology
  • Pneumonia, Bacterial* / diagnosis
  • Pneumonia, Bacterial* / microbiology
  • Pneumonia, Viral* / diagnosis
  • Pneumonia, Viral* / virology
  • Polymerase Chain Reaction / methods*
  • Viruses* / classification
  • Viruses* / genetics
  • Viruses* / isolation & purification
  • Young Adult

Substances

  • Culture Media
  • DNA, Bacterial
  • DNA, Viral