Lower respiratory tract virus findings in mechanically ventilated patients with severe community-acquired pneumonia

Clin Infect Dis. 2014 Jul 1;59(1):62-70. doi: 10.1093/cid/ciu237. Epub 2014 Apr 11.


Background: The role of viral infections in the etiology of severe community-acquired pneumonia (SCAP) was prospectively evaluated from 2008 to 2012 at a university-level intensive care unit.

Methods: Clinical data and microbiological tests were assessed: blood cultures, urine pneumococcal and legionella antigens, Mycoplasma pneumoniae and Chlamydia pneumoniae antibodies from paired serums, and respiratory virus detection by multiplex, real-time polymerase chain reaction (PCR) from nasopharyngeal swabs and lower tracheal specimens via intubation tube.

Results: Of 49 mechanically ventilated SCAP patients (21 men and 28 women; median age, 54 years), the etiology was identified in 45 cases (92%). There were 21 pure bacterial infections (43%), 5 probably pure viral infections (10%), and 19 mixed bacterial-viral infections (39%), resulting in viral etiology in 24 patients (49%). Of 26 viruses, 21 (81%) were detected from bronchial specimens and 5 (19%) from nasopharyngeal swabs. Rhinovirus (15 cases, 58%) and adenovirus (4 cases, 15%) were the most common viral findings. The bacterial-viral etiology group had the highest peak C-reactive protein levels (median, 356 [25th-75th percentiles, 294-416], P = .05), whereas patients with probably viral etiology had the lowest peak procalcitonin levels (1.7 [25th-75th percentiles, 1.6-1.7]). The clinical characteristics of pure bacterial and mixed bacterial-viral etiologies were comparable. Hospital stay was longest among the bacterial group (17 vs 14 days; P = .02).

Conclusions: Viral findings were demonstrated in almost half of the SCAP patients. Clinical characteristics were similar between the pure bacterial and mixed bacterial-viral infections groups. The frequency of viral detection depends on the availability of PCR techniques and lower respiratory specimens.

Keywords: etiology; intensive care; severe community-acquired pneumonia; viral infection.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Cohort Studies
  • Community-Acquired Infections / epidemiology*
  • Community-Acquired Infections / pathology
  • Community-Acquired Infections / virology*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Multiplex Polymerase Chain Reaction
  • Pneumonia, Viral / epidemiology*
  • Pneumonia, Viral / pathology
  • Pneumonia, Viral / virology*
  • Prospective Studies
  • Real-Time Polymerase Chain Reaction
  • Respiration, Artificial
  • Viruses / classification*
  • Viruses / isolation & purification*
  • Young Adult