Table 3.

Microbial etiology of Community-Acquired Pneumonia in the elderly patients [2,9,69,70,72,76].

Microorganism	Frequency
Streptococcus pneumoniae	10%–50%
Intracellular bacteria	2%–15%
Haemophilus influenzae	1%–10%
Respiratory viruses	2%–20%
Pseudomonas aeruginosa	1%–15%
Staphylococcus aureus	1%–7%
Polymicrobial etiology	2%–13%
Enterobacteriaceae	1%–3%
Aspiration	10%