1976 Philadelphia Legionnaires' disease outbreak 1976 Philadelphia Legionnaires' disease outbreak The 1976 Legionnaires disease outbreak, occurring in the late summer in Philadelphia, Pennsylvania, was the first occasion in which a cluster of a particular type of pneumonia cases were determined to be caused by the "Legionella pneumophila" bacteria. Previous outbreaks were retroactively diagnosed as being most probably caused by Legionella bacteria. On July 21, 1976, the American Legion opened its annual three-day convention at the Bellevue-Stratford Hotel in Philadelphia, Pennsylvania. More than 2,000 Legionnaires, mostly men, attended the convention. The date and city were chosen to coincide with America’s celebration of the 200th anniversary of
Legionella clemsonensis Legionella clemsonensis Legionella clemsonensis was isolated in 2006, but was discovered in 2016 by Clemson University researchers. It is a Gram-negative bacterium. “"Legionella"” is named after the American Legion convention where the first outbreak occurred, killing 34 people and sickening 221 individuals in 1976. It occurred in Philadelphia during the convention for the association of the U.S. veterans. The specific name "clemsonensis"” derives from Clemson University, where undergraduates DNA-sequenced this new strain. "Legionella" has a correlation with another genus called "Coxiella". Both cause lung infection that can eventually lead to pneumonia due to the intracellular bacteria in aerosols. Based on