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 of age. It occurs about five times more frequently in the developing world versus the developed world. Viral pneumonia accounts for about 200 million cases. Hospital-acquired pneumonia is pneumonia that is acquired in a hospital setting at least 48 hours after being admitted. Pneumonia the second most common hospital-acquired disease, while also being the leading cause of death among hospital-acquired infections. Hospital-acquired pneumonia is also seen to be the cause for nearly half of all the antibiotics taken within hospitals worldwide. A sub-type of hospital-acquired pneumonia, known as ventilator-associated pneumonia, is described as pneumonia acquired more than 48 hours after