The severity of radiographic abnormality correlated with the presence of Legionella pneumophila detectable in sputum by direct immunofluorescence (p less than 0.001). No correlation of radiographic severity to smoking, immunosuppression, advanced age, race, or underlying disease, nor to symptoms of abdominal pain, diarrhea, neurologic abnormalities or high fever, nor to laboratory data including hyponatremia, leukocytosis, or hematuria was found.
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