Susan C. Ball, MD, MPH

Mr D is a 38-year-old African American man in whom AIDS had been diagnosed in 2001; he had responded well to antiretroviral therapy, with a recent CD4+ cell count of 376/µL and an HIV RNA level less than 50 copies/mL. He presented to our clinic complaining of a mildly tender "lump" on the left side of his neck, which he first noticed a week ago. He denied fever, chills, sweats, cough, anorexia, weight loss, and urinary symptoms but had a sore throat for 2 days.

Legionella species are among the leading causes of community-acquired pneumonia (CAP) in the general population, and although rare in patients with HIV infection, Legionella pneumonia is associated with significant morbidity and mortality