1976 Philadelphia Legionnaires' disease outbreak failed. The disease was finally produced in guinea pigs. The CDC announced the discovery at a press conference on January 18, 1977. The bacterium was later named "Legionella pneumophila". "Legionella pneumophila" is the most common cause, but sometimes other species of Legionella bacteria also cause Legionnaires' disease. The terms "Philadelphia fever" and "Legion fever" appear to have been used at the time of the outbreak and for shortly thereafter, although at least one 2008 source which covers disease in a historical narrative sense also included "Legion Fever" as alternate name. Both the World Health Organization in 2018 and the United
Epidemiology of pneumonia case fatality rate in the UK is around 5–10%. In the United States, community-acquired pneumonia affects 5.6 million people per year, and ranks 6th among leading causes of death. In 2009, there were approximately 1.86 million emergency department encounters for pneumonia in the United States. In 2011, pneumonia was the second-most common reason for hospitalization in the U.S., with approximately 1.1 million stays—a rate of 36 stays per 10,000 population. Pneumonia was one of the top ten most expensive conditions seen during inpatient hospitalizations in the U.S. in 2011, with an aggregate cost of nearly $10.6 billion for 1.1 million