Legionella micdadei infection presenting as severe secretory diarrhea and a solitary pulmonary mass.

Sixty percent of infections with non-pneumophila species of Legionella are caused by Legionella micdadei. Although diarrhea is a common symptom of legionellosis, including that due to L. micdadei infection, severe, life-threatening diarrhea is rare. We describe a patient with profound secretory diarrhea (secretion rate, up to 8 L/day) that was secondary to culture-proven L. micdadei pneumonia. In addition, a 3-cm pulmonary nodule was detected, which completely resolved after proper treatment for Legionella infection. Resolving pulmonary nodules have been previously reported in association with treatment of L. micdadei infections.