|Description:||This 2005 photograph shows numbers of Legionella sp. colonies, which had been cultivated on an agar cultured plate, and illuminated using ultraviolet light.|
At least 46 Legionella spp., and 70 serogroups have been identified. L. pneumophila, an ubiquitous aquatic bacterial organism, which thrives in warm environments, primarily at temperatures ranging from 32°- 45°C, causes over 90% of Legionnaires' disease (LD) in the United States. LD is the more severe form of legionellosis, and is characterized by pneumonia, commencing 2 - 10 days after exposure. Pontiac fever represents an acute-onset, manifesting as a flu-like, non-pneumonic illness, and occurs within a few hours, to two days after exposure.