Impact of bacterial infections on airway diseases

Bacterial infections play an important role as aetiologic agents in acute exacerbations of chronic obstructive pulmonary disease (COPD). Modern investigational tools, including bronchoscopy, microbial molecular epidemiology and measurement of specific immunity have established that bacteria cause up to 50% of acute exacerbations in COPD. Acute exacerbations have enormous economic costs and contribute to morbidity, mortality and impairment in health related quality of life. Chronic bacterial persistence in the lower airways and lower respiratory tract in patients with COPD is not innocuous. It is likely to contribute to persistent airway inflammation and might contribute to acute airway exacerbations or progression of airway obstruction. Further investigation is required in these fertile areas of investigation. Bacteria also play a role in asthma exacerbations, but their role is less well defined than with patients with COPD. Mycoplasma pneumoniae may be associated with asthma chronicity. Chronic airway infection models document that M. pneumoniae plays a role in airway remodelling, including angiogenesis, vascular remodelling and airway wall thickening. Recent studies have identified patients with asthma as an at-risk group for invasive pneumococcal disease. The feasibility and cost effectiveness of a pneumococcal vaccination strategy among persons with asthma deserves careful, immediate attention