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
Atypical pneumonia process most often involves the lower lobe, but may affect any lobe or combination of lobes. Mycoplasma is found more often in younger than in older people. Older people are more often infected by Legionella. Atypical pneumonia Atypical pneumonia, also known as walking pneumonia, is the type of pneumonia not caused by one of the pathogens most commonly associated with the disease. Its clinical presentation contrasts to that of "typical" pneumonia. A variety of microorganisms can cause it. When it develops independently from another disease it is called primary atypical pneumonia (PAP). The term was introduced in the 1930s and