| Infecting Organism | Initial Radiographic Worsening | Maximum Time to Resolution | Residual Radiographic Abnormalities |
|---|---|---|---|
| Streptococcus pneumoniae | |||
| Bacteremic | Majority | 3-5 months | 25-35% |
| Nonbacteremic | Occasional | 1-3 months | Rare |
| Group B Streptococci | Common | 1-3 months | Common |
| Staphylococcus aureus | Majority | 3-5 months | Common |
| Haemophilus influenzae | Occasional | 1-5 months | Occasional |
| Legionella | Majority | 3-5 months | 25% |
| Chlamydia pneumoniae | Rare | 1-3 months | Occasional |
| Moraxella catarrhalis | Rare | 1-3 months | Uncommon |
| Enteric gram-negative organisms | Occasional | 3-5 months | 10-20% |
| Viruses | Variable | Variable | Occasional fibrosis, bronchiolitis obliterans organizing pneumonia |
| Mycoplasma pneumoniae | Variable | Variable | Uncommon |
| *Modified from Niederman MS, Sarosi GA. Respiratory Infections. Philadelphia, W.B. Saunders Co., 1994, 278. | |||