Respiratory Virus

Studies have indicated that approximately one-third of all episodes of COPD exacerbations are associated with viral infection. Lab tests show that the viral infection present during an exacerbation is significantly greater than during a stable period of COPD. Common viral pathogens include influenza, parainfluenza, rhinovirus, coronavirus, adenovirus, and respiratory syncytial virus.

Researchers speculate that the severity of the episodes may be related to the causative pathogen(s). One study suggests that episodes associated with viral infection tend to be less severe than those associated with bacteria. If the episode is severe, and if there is a viral pathogen present, a bacterial pathogen may also be present. Seemungal, et al found an association between increased dyspnea and the common cold during exacerbations; their findings indicated that viral infections may result in prolonged exacerbations.