Legionnaires' disease that occur globally is not known. Legionnaires' disease is the cause of an estimated 2-9% of pneumonia cases that are acquired outside of hospital. An estimated 8,000 to 18,000 cases a year in the United States require hospitalization. Outbreaks of disease account for a minority of cases. While it can occur any time of the year, it is more common in the summer and fall. The disease is named after the outbreak where it was first identified, at a 1976 American Legion convention in Philadelphia. The length of time between exposure to the bacteria and the appearance of symptoms is
Aspiration pneumonia area of consolidation, where liquids accumulate in a particular region of the lung, in alcoholics who aspirate in the supine position. Aspiration pneumonia is typically diagnosed by a combination of clinical circumstances (people with risk factors for aspiration) and radiologic findings (an infiltrate in the proper location). A chest x-ray is typically performed in cases where any pneumonia is suspected, including aspiration pneumonia. Findings on chest x-ray supportive of aspiration pneumonia include localized consolidation depending on the patient's position when the aspiration occurred. For example, people that are supine when they aspirate often develop consolidation in the left lower lobe