Severe Community-Acquired Pneumonia (CAP) due to Atypical Pathogens

Community-acquired pneumonia (CAP) is a relatively common and potentially serious infection that affects both immunocompetent and immunosuppressive adults throughout the world. The annual incidence of CAP in the United States is approximately 4 million cases. CAP due to atypical pathogens accounts for approximately 20 to 40 percent of cases necessitating hospitalization. There are few data regards to the prevalence rates of severe CAP due to atypical pathogens necessitating admission to the intensive care unit. This review article summarizes clinical features, diagnostic criteria, differential diagnosis, and management based on guidelines of medical societies.