Legionnaires' disease in renal transplant patients.

Legionnaires disease, which is commonly manifested as pneumonia, was only recently recognized to be a bacterial infection. Diagnosis can be difficult because Gram's stain does not readily stain the bacterium in pulmonary secretions, the organism is not readily cultured, and legionellae is not affected by many commonly used antibiotics. In a retrospective review of all of our transplant patients, we identified 14 cases of Legionnaires' disease after 101 renal transplants. The patients characteristically had high fever, polymorphonuclear leukocytosis, dyspnea and an unproductive cough accompanied by radiographic changes of consolidating pneumonia. Legionnaires' disease can be diagnosed by direct immunofluorescent antibody staining, culture on special media or increases in serum titers of legionella antibodies in surviving patients. Since the recognition of Legionnaires' disease in 1977, we have successfully treated seven renal transplant patients using erythromycin with or without rifampin.