First reported United States case of Legionella pneumophila serogroup 1 pneumonia in a patient receiving anti-tumor necrosis factor-alpha therapy.

Legionellosis has been reported to be an extremely rare disease in Hawai'i. The authors report a case of a 67-year-old woman with a history of rheumatoid arthritis treated with long-term adalimumab who developed severe right-sided community-acquired pneumonia and a parapneumonic effusion. Legionella pneumophila serogroup 1 was confirmed as the microbiologic cause based on a positive urine Legionella antigen as well as direct fluorescent antibody and Legionella culture of bronchoalveolar lavage.