TABLE 32-1. -- Common Causes of Community-Acquired Pneumonia in

Patients Who Do Not Require Hospitalization*

Mycoplasma pneumoniaeStreptococcus pneumoniae

Chlamydophila pneumoniaeHaemophilus influenzae

Respiratory viruses

TABLE 32-3. -- Common Causes of Severe Community-Acquired Pneumonia*] [†

Streptococcus pneumoniaeEnteric gram-negative bacilliStaphylococcus aureusLegionella spp.Mycoplasma pneumoniaeRespiratory virusesPseudomonas aeruginosa (relative frequency determined by the presence or absence of specific risk factors)

32-2 -- .Common Causes of Community-Acquired Pneumonia in Patients Who Require Hospitalization*

Streptococcus pneumoniaeMycoplasma pneumoniae

Chlamydophila pneumoniaeHaemophilus influenzae

Mixed infectionsEnteric gram-negative bacilli

Aspiration (anaerobes)Respiratory viruses

Legionella spp.

• PATIENTS WHO DO REQUIRE HOSPITALIZATION • Two sets of blood cultures• Gram stain and culture of a valid sputum sample• Urinary antigen test for detection of Legionella pneumophila (in endemic areas or during outbreaks)• Stain for acid-fast bacilli and culture of sputum (if tuberculosis is suggested by clinical history or radiologic findings)• Fungal stain and culture of sputum, and fungal serologies (if infection by an endemic mycosis is suggested by the clinical history or radiologic findings)• Sputum examination for Pneumocystis jirovecii (if suggested by clinical history or radiologic findings)• Serologies for Mycoplasma pneumoniae, Chlamydophila pneumoniae, Chlamydophila psittaci, Coxiella burnetii, Legionella spp., and respiratory viruses (in endemic areas or during outbreaks)• Culture and microscopic evaluatio