Community-Acquired Pneumonia

Community-acquired pneumonia is a major cause of morbidity and mortality. The features of pneumonia result from an inflammatory response to infectious agents in the alveolar space, but the infectious etiology often remains undetermined. Major risk factors for the development of pneumonia include advanced age and medical comorbidities. The commonest causes remain Streptococcus pneumoniae and viruses, but a broad array of other pathogens may cause infection in patients with defined risk factors. The chest radiograph remains a key part of the investigation. Increasing molecular tests, including nucleic acid amplification tests, are supplementing traditional culture-based diagnosis. Empiric antimicrobials should be started early and are based on severity scores and local epidemiology to ensure appropriate coverage that minimizes unwanted consequences of broad-spectrum therapy. Vaccination and cigarette smoking programs are key preventive strategies.