Managing Community-Acquired Pneumonia in Adults

Community-acquired pneumonia (CAP), also known as community-acquired bacterial pneumonia (CABP), is an infection of the lungs that is acquired outside of the hospital setting. Lower respiratory infections including CAP are the leading cause of death from infectious disease in the world. In the US, there were 1.3 million emergency department visits and 49,157 deaths attributed to pneumonia in 2017. When combined with influenza, pneumonia was the eighth leading cause of death in the US. In the elderly, CAP has a higher burden of hospitalization and total cost than heart attack, stroke, and fractures combined. It is linked to 1.5 million hospitalizations in adults each year, with an estimated mortality rate of 6.5% during hospitalization.6 In October of 2019, the American Thoracic Society, along with the Infectious Diseases Society of America, published an updated guideline on the diagnosis and treatment of adults with CAP.This guideline is the long-awaited update to the 2007 version published by the same groups. This update does not provide recommendations for managing foreign travelers or patients who are immunocompromised (eg, patients receiving cancer chemotherapy, bone marrow transplant recipients, HIV patients, etc.). Notable changes to the guideline include the removal of the healthcare-associated pneumonia category, the use of empiric amoxicillin monotherapy for outpatients with no coexisting conditions (eg, chronic lung, heart, liver, or kidney disease; diabetes, asplenia, malignancy, or alcoholism), and the use of macrolide monotherapy only if local resistance rates are less than 25%. This issue summarizes the causes, risk factors, and current treatment recommendations for CAP in adults. The 2019 guideline was released before the pandemic caused by severe acute respiratory syndrome coronavirus  (SARSCoV-2). The guideline and this issue do not include information on managing CAP in patients with coronavirus disease 2019 (COVID-19).