Pneumonia and Other Pulmonary Infections

Abstract

Pulmonary infections span a wide spectrum, ranging from self-limited to life threatening. Pneumonia refers to infection of lung parenchyma, specifically the alveolar or gas-exchanging portions of the lung. Taken together, pneumonia and influenza rank as the sixth leading cause of death in the United States and the leading infectious cause of death in the United States and the world. Tuberculosis (TB) is a bacterial disease caused by Mycobacterium tuberculosis. TB, historically a leading cause of death worldwide, remains an enormous global public health epidemic in much of the developing world. Rates of coinfection with HIV are high, and HIV increases the morbidity and mortality associated with TB. This review details the pathophysiology, epidemiology, clinical presentation, and treatment of pulmonary infection, including pneumonia, empyema, pulmonary abscess, and tuberculosis (TB). Figures show chest radiographs of reactivation pulmonary tuberculosis, HIV-infected patients with proven culture-confirmed tuberculosis, prominent hilar adenopathy with clear lung fields, and bilateral interstitial changes; and treatment of drug-susceptible pulmonary tuberculosis. Tables list major causes of pulmonary infection, host defence mechanisms against pulmonary infection, initial empirical antibiotic therapy in patients with suspected community-acquired pneumonia, initial antibiotic therapy for community-acquired pneumonia in outpatients, initial antibiotic therapy for community-acquired pneumonia in patients who require hospitalization, antibiotic choices for aspiration pneumonia, pneumonia severity index scoring, and mortality by pneumonia severity index point score. This review contains 2 figures, 9 tables, and 87 references Key words: Pulmonary infections; Pneumonia; Tuberculosis; Lung infection; Mycobacteria; Community-acquired pneumonia; Health care-associated pneumonia; Aspiration pneumonia; Empyema; Legionnaires disease