Aetiology of HAP in patients with COPD and bronchiectasis

The most common pathogens that cause HAP in patients with chronic obstructive pulmonary disease (COPD) and bronchiectasis are the same as in patients without comorbid lung disease (eg Streptococcus pneumoniae, gram-negative bacteria). Due to frequent infections and antibiotic exposure, sputum culture results may identify multidrug-resistant bacteria (eg Pseudomonas aeruginosa). However, these bacteria are more likely to be colonising organisms rather than the cause of pneumonia.