Community-acquired pneumonia (CAP) is an infection that begins outside the hospital or is diagnosed within 48 hours after admission to the hospital in a person who has not resided in a long-term care facility for 14 days or more before admission (Grossman, & Porth, 2014). As according to Ferri (2017), the incidence of community-acquired pneumonia (CAP) is 1 in 100 persons. CAP is the most common infectious cause of death in the U.S. (p. 983).
The most common cause of infection is S. pneumoniae. Other common pathogens include H. influenza, S. aureus, and gram-negative bacilli. Less common agents are Mycoplasma pneumoniae, Legionella, Chlamydia species, and viruses, sometimes called atypical agents. Common viral causes of CAP include the influenza virus, RSV, adenovirus, and parainfluenza virus (Grossman, & Porth, 2014).