Community-Acquired Pneumonia in Adults

Community-acquired pneumonia (CAP) is diagnosed based on clinical signs and symptoms (see Figure 1) plus new infiltrates on imaging.

The causative pathogen is identified in less than half of CAP cases. Still, clinicians should test for treatable pathogens including Streptococcus pneumoniae — which remains the most common bacterium — Legionella, and respiratory viruses (e.g., influenza, SARS-CoV-2).

Clinicians can use clinical prediction tools such as the Pneumonia Severity Index and CURB-65 score to guide hospital admission decisions and the American Thoracic Society/Infectious Diseases Society of America 2007 criteria for intensive care unit (ICU) admission.

Outpatient providers can consider amoxicillin, amoxicillin-clavulanate, ma…