Legionella micdadei (Pittsburgh pneumonia agent). Two infections with unusual clinical features.

We describe herein the clinical features, diagnosis, and successful treatment of two patients with Legionella micdadei pneumonia, the Pittsburgh pneumonia agent. The rapid pulmonary cavitation and relapse of symptoms after a course of therapy in a renal transplant recipient, and the prolonged illness with hemorrhagic pleural fluid, splenomegaly, and multiple-organ dysfunction in a nonimmunocompromised host, illustrate the clinical spectrum of infections with this organism.