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Key Points
➤ This guideline addresses the clinical entity of pneumonia that
is acquired outside of the hospital setting in patients in the U.S.
who have not recently completed foreign travel and who do not
have an immunocompromising condition.
➤ Antibiotic recommendations for the empiric treatment of
community-acquired pneumonia (CAP) are based on selecting
agents effective against the major treatable bacterial causes
of CAP.
• Traditionally, these bacterial pathogens include Streptococcus pneumoniae,
Haemophilus influenzae, Mycoplasma pneumoniae, Staphylococcus aureus,
Legionella species, Chlamydia pneumoniae, and Moraxella catarrhalis.
➤ In addition, the emergence of multidrug-resistant pathogens,
including methicillin-resistant S. aureus (MRSA) and
Pseudomonas aeruginosa require separate recommendations
when the risk of each of these pathogens is elevated.
➤ Other, far less common, multidrug-resistant Enterobacteriaceae
can cause CAP, including organisms producing extended-
spectrum beta-lactamase (ESBL). Those organisms are effectively
covered by P. aeruginosa strategies and are therefore not
otherwise mentioned.
➤ Bacterial pathogens often co-exist with viruses, and there
is no current diagnostic test accurate enough or fast enough
to determine that CAP is due solely to a virus at the time of
presentation. Therefore, our initial recommendations are to treat
empirically for possible bacterial infection or co-infection.
