Legionnaires' disease acquired its name in July 1976, when an outbreak of pneumonia occurred among people attending a convention of the American Legion at the Bellevue-Stratford Hotel in Philadelphia. Of the 182 reported cases, mostly men, 29 died. On January 18, 1977, the causative agent was identified as a previously unknown strain of bacteria, subsequently named "Legionella", and the species that caused the outbreak was named "Legionella pneumophila". Outbreaks of Legionnaires' disease receive significant media attention, but this disease usually occurs in single, isolated cases not associated with any recognized outbreak. When outbreaks do occur, they are usually in the summer and
Legionella cherrii were cultured around 36 °C in an environment containing 2.5% carbon dioxide. The genus "Legionella" is named after the 1976 pneumonia ("Legionella pneumophila") outbreak at the American Legion convention at the Bellevue-Stratford Hotel in Philadelphia. The genus was previously unknown, but it was established three years later. The specific term "cherrii" is derived from the scientist William B. Cherry due to his contributions on the studies of Legionellae. "L. cherrii" is rod-shaped and considered an oxidase-negative bacterium since it lacks cytochrome c oxidase and does not use oxygen in its electron transport chain. "L. cherrii" also has the ability to