12/1,000/year, about 600,000 hospitalization cases per year (in the U.S.).
The 6th leading cause of death in the U.S. (7th in Taiwan).
The most common cause of death due to infectious disease
Primarily involve the interstitium or the alveoli.
Sudden onset of fever (80%)
Sputum production (66%)
Pleuritic pain (50%)
Signs of pulmonary consolidation (dullness, increased fremitus, egophony, bronchial breatathing sound, rales)
More gradual onset
Legionella-CNS, heart, liver, GI and GU
M.pneumoniae- upper RT, GI, skin
The point that extrapulmonary organ involvement separate atypical from typical pneumonia cannot be overemphasized!
Prompt and accurate diagnosis of CAP is important, since it is the only acute respiratory tract infection in which delayed antibiotic treatment has been associated with increased risk of death.