Legionnaires' disease Synonyms legionellosis,[1] Legion fever Transmission electron microscopy image of L. pneumophila, responsible for over 90% of Legionnaires' disease cases[2] Classification and external resources Specialty Infectious disease, pulmonology ICD-10 A48.1, A48.2 ICD-9-CM 482.84 DiseasesDB 7366 MedlinePlus 000616 eMedicine med/1273 MeSH D007876 Orphanet 549