Abstract

Community-acquired pneumonia (CAP) is a costly disease that is associated with significant morbidity and mortality. The growing prevalence of this disease has resulted in various advances in diagnosis and treatment. The most common pathogens of CAP include Streptococcus pneumoniae, Haemophilus influenzae, and atypical pathogens; however, the underlying pathogen often is unknown. Treatment of CAP has evolved because of changing etiologic patterns and increasing antimicrobial resistance among common respiratory pathogens. Among the groups that have established treatment guidelines for CAP are the American Thoracic Society (ATS), the Infectious Diseases Society of America (IDSA), and the Centers for Disease Control and Prevention (CDC). These guidelines establish risk factors associated with drug resistance or infection with specific pathogens. In addition, each guideline provides unique recommendations that are similar in some ways, yet different in others. By understanding the various risk factors for drug resistance and the treatment options endorsed by these guidelines, physicians can treat patients with the most appropriate antimicrobial available.