1976 Philadelphia Legionnaires' disease outbreak States Center for Disease Control and Prevention (CDC) in 2017 only use the term Legionnaires' disease to refer to the serious version with pneumonia. CDC investigators quickly discovered outbreaks of respiratory disease caused by "L. pneumophila" dating back to 1959. An outbreak of what was dubbed Pontiac fever occurred in a health department in Pontiac, Michigan in July 1967. No one died. Although caused by the same bacterium, Pontiac fever is a milder ailment than Legionnaires' disease. Pneumonia is absent in those with Pontiac fever. An outbreak of pneumonia in July–August, 1965, at St. Elizabeths Hospital in Washington, DC, which
Epidemiology of pneumonia Epidemiology of pneumonia Pneumonia is a common illness affecting approximately 450 million people a year and occurring in all parts of the world. It is a major cause of death among all age groups, resulting in 1.4 million deaths in 2010 (7% of the worlds yearly total) and was the 4th leading cause of death in the world in 2016, resulting in 30 million deaths worldwide. Pneumonia is a type of lower respiratory tract infection, and is also the most deadly communicable disease as of 2016. Rates are greatest in children less than five and adults older than 75 years