Pneumonia, Community-Acquired (Adult)

PATHOGENS

Commonly encountered organisms are listed below:

• Streptococcus pneumoniae
• Haemophilus influenzae
• Moraxella catarrhalis
• Chlamydophila pneumoniae
• Legionella species
• Mycoplasma pneumoniae
• Viruses:
  • SARS-CoV-2
  • Influenza A or B
  • RSV
  • Human metapneumovirus
  • Rhinovirus
  • Painfluenza
  • Adenovirus
• Mycobacterium tuberculosis
• Nocardia
• Group A Streptococcus
• Neisseria meningiditis
• Anaerobes
  • Aspiration pneumonia
• Gram negatives
  • In some CAP series, it may account for 5-10% of cases.
    • Risks include COPD, current corticosteroid use, and prior antibiotic therapy.
      • Severe CAP: GN bacterial pneumonia is more common in severe cases and is associated with higher mortality.