Legionella Penumonia Diagnosed by Urinary Antigen Detection

: A 63-year-old man with dyspnea and high fever was admitted to the hospital. A pneumonic shadow in the right lower lung field was observed. After administration of rifampicin and clarithromycin, his symptoms were gradually alleviated. Although Legionella pneumonia was highly suspected, Legionella pneumophila was not isolated from his sputum specimens and the serum level of indirect immunofluorescent antibody titer was not significantly elevated. However, we believe it is very likely that he had Legionella pneumonia, because we detected a high density of urinary Legionella pneumophila serogroup 1 antigen by antigen capture EIA.