Common organisms in community-acquired pneumonia
| Outpatient care |
| Streptococcus pneumoniae |
| Mycoplasma pneumoniae |
| Haemophilus influenzae |
| Chlamydophila pneumoniae |
| Respiratory virus (influenza A and B, adenovirus, respiratory syncytial virus, parainfluenza) |
| Inpatient (non-intensive care) |
| S pneumoniae |
| M pneumoniae |
| C pneumoniae |
| H influenzae |
| Legionella species |
| Aspiration-related oral flora |
| Respiratory viruses |
| Inpatient (intensive care) |
| S pneumoniae |
| Staphylococcus aureus |
| Legionella species |
| Gram-negative bacilli |
| H influenzae |
From Mandell LA, Wunderink RG, Anzueto A, et al; Infectious Diseases Society of America; American Thoracic Society. Infectious Diseases Society of America/American Thoracic Society consensus guidelines on the management of community-acquired pneumonia in adults. Clin Infect Dis 2007; 44(suppl 2):S27–S72, by permission of Oxford University Press.