Until recently, bacterial infections in the lung were believed to be the primary cause of COPD exacerbation, with air pollution and unknown causes being second runner up. A recent state-of-the art literature review reports that viruses should also be added to this list and that bacteria is also associated with stable COPD.
COPD exacerbation is defined as having an acute worsening of COPD symptoms. It is the main reason that people with COPD are admitted to the hospital, and one of the primary causes of death in the COPD population. Because prevention of COPD exacerbation can greatly reduce morbidity and mortality rates, it remains a primary goal in COPD treatment.
Historically, bacteria have played a major role in COPD exacerbation, with treatment centering around antibiotics. However, bacteria are also present in patients who are stable, which suggests that having a bacterial infection does not automatically lead to an exacerbation. On-the-contrary, the outcome of a bacterial infection is strongly influenced by other factors involving both patient and bacteria. Moreover, because COPD exacerbation occurs more frequently in Winter and is often preceded by cold symptoms, researchers now believe that respiratory viral infections are also a causative factor in acute exacerbation of symptoms, for which antibiotics should not be prescribed.
In conclusion, the review points out that bacteria and viruses play a major role in stable COPD and the development of COPD exacerbation. Because there are different types of bacteria and different strains of each type, developing new methods to detect and identify these pathogens will lead to more effective treatment and a better understanding of the role bacteria play in COPD. Finally, before being treated with an antibiotic for COPD exacerbation, it is crucial that the specific infectious agent -- whether bacterial or viral -- be identified. This way, doctors can prescribe the appropriate treatment, whether that be an antibiotic or an anti-viral.
Read more about COPD exacerbation:
Beasley, Victoria, et. al. Lung microbiology and exacerbations in COPD. International Journal of COPD. 30 August 12, 2012:7 555-569.