Risk Factors for Community-acquired Pneumonia in Adults: A Review

© 2016 Wolters Kluwer Health, Inc. The knowledge of risk factors for community-acquired pneumonia (CAP) is essential to the design of preventive measures to reduce its incidence. We present a review of the main risk factors for CAP in adults, paying particular attention to chronic comorbidities, medication, and lifestyle factors. The most frequently observed comorbidities associated with CAP are chronic obstructive pulmonary disease, asthma, and heart failure. Certain lifestyle factors such as smoking, dental hygiene, nutritional and dietary habits, and certain working and environmental conditions (such as contact with dust and sudden changes of temperature) have been shown to be modifiable risk factors for CAP. Moreover, in the elderly, oropharyngeal dysphagia is a major risk factor for CAP, as an impaired swallow response and delayed airway protection favor tracheobronchial aspirations. Finally, vaccination against pneumococcal disease with the pneumococcal conjugate vaccine (PCV-13) has been shown to be effective and is recommended for high-risk patients and elderly individuals, as Streptococcus pneumoniae is the most frequently isolated pathogen from patients with CAP.