Legionnaires' disease and fever of unknown origin.

In a patient with fever of unknown origin and granulomas of the liver extensive serological testing revealed a significant rise in antibodies only to Legionella pneumophila despite the fact that he never was shown to have pneumonia. Absorption studies yielded additional evidence that this immunological response was specific for L. pneumophila. Bacteremia and extrapulmonary involvement, including the liver, has been shown with L. pneumophila, but never without pneumonia. Furthermore, granulomas of the liver have not been described in connection with legionellosis. This patient is regarded as a case of fever of unknown origin related to L. pneumophila infection.