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
Hospital-acquired pneumonia diabetes). The number of residents in long term care facilities is expected to rise dramatically over the next 30 years. These older adults are known to develop pneumonia 10 times more than their community-dwelling peers, and hospital admittance rates are 30 times higher. Nursing home-acquired pneumonia is an important subgroup of HCAP. Residents of long term care facilities may become infected through their contacts with the healthcare system; as such, the microbes responsible for their pneumonias may be different from those traditionally seen in community-dwelling patients, requiring therapy with different antibiotics. Other groups include patients who are admitted as a