Importance of viral and bacterial infections in chronic obstructive pulmonary disease exacerbations

J Clin Virol. 2009 Oct;46(2):129-33. doi: 10.1016/j.jcv.2009.07.010. Epub 2009 Aug 7.


Background: Few studies have evaluated the contribution of both viruses and bacteria in acute exacerbation of chronic obstructive pulmonary disease (AECOPD).

Objectives: This study estimated the burden of both types of pathogens among adults seeking care for an AECOPD during two consecutive winter seasons.

Study design: Patients 50 years or older who consulted within 10 days of AECOPD onset were eligible. Clinical data were collected on a standardized questionnaire, and nasopharyngeal aspirates (NPA), paired sera, and non-induced sputum were collected. Polymerase chain reaction (PRC) assays were used to identify viral, atypical and bacterial pathogens in NPA specimen.

Results: Overall, 108 patients with AECOPD were included, 88% of patients were admitted and 2 patients (2%) received intensive care. A third of patients (31%) had evidence of a viral infection, 9% with influenza A, 7% RSV and 7% with PIV-3. One patient was positive for Mycoplasma pneumoniae. Bacterial pathogens were identified in 49% of patients with available sputum, most frequently Staphylococcus aureus, Pseudomonas aeruginosa, and Haemophilus influenzae. Among virus-infected patients, 14 (58%) also had bacteria in their sputum, but co-infected patients did not present with different symptoms than patients with single infections.

Conclusions: These results suggest that influenza and RSV are frequent contributors of AECOPD, and that coinfection with bacteria does not appear to be more severe among virus-infected patients. Clinicians should be aware that AECOPD may be frequently triggered by viruses, and may consider antivirals and proper infection control measures in appropriate epidemiological setting.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Bacterial Infections / complications
  • Bacterial Infections / microbiology
  • Female
  • Humans
  • Influenza A virus / isolation & purification
  • Influenza, Human / complications
  • Male
  • Middle Aged
  • Pulmonary Disease, Chronic Obstructive / microbiology*
  • Pulmonary Disease, Chronic Obstructive / virology
  • Respiratory Syncytial Virus Infections / complications
  • Respiratory Syncytial Viruses / isolation & purification
  • Respiratory Tract Infections / complications*
  • Respiratory Tract Infections / microbiology
  • Respiratory Tract Infections / virology
  • Risk Factors
  • Sputum / microbiology
  • Virus Diseases / complications
  • Virus Diseases / virology